416 Questions
What is the main reason why HBV infection is not curable?
The virus genome persists and is archived inside hepatocytes
What is the main difference between HCV and HBV?
HCV infection is curable, while HBV infection is not curable
What is the main issue with stop codons and deletions in HBsAg?
They can lead to liver cancer even if the patient has undetectable viremia
What is the mechanism of action of ribavirin?
It inhibits the inosine monophosphate deidrogenase enzyme, leading to reduced synthesis of guanine nucleotides and inhibition of viral nucleic acids production
What is the mechanism of action of amantadine and rimantadine against influenza virus?
They block the M2 viral proton pump
Which of the following drugs is used for the treatment of herpes simplex virus?
Penciclovir
What is the mechanism of action of acyclovir against herpes viruses?
It inhibits viral DNA polymerase
Which of the following drugs has high activity against cytomegalovirus?
Ganciclovir
What is the goal of HIV treatment with ART?
To suppress the virus to undetectable levels
What is the main function of neuraminidase in the influenza virus life cycle?
To cleave sialic acid residues on glycoprotein during the entry of virus into target cell
Which of the following antiviral drugs is administered via inhalation?
Zanamivir
What is the target of M2 protein in anti-influenza drugs?
To determine an acidification of the endocytic vesicle
What is the mechanism of action of neuraminidase inhibitors?
They block the activity of neuraminidase by mimicking the structure of sialic acid residues
What are the key treatment goals for individuals living with HIV?
Maximally and durably suppress plasma HIV RNA, restore and preserve immunologic function, reduce HIV-associated morbidity and prolong the duration and quality of survival, and prevent HIV transmission
What happens if HIV therapy is stopped?
HIV returns rapidly
What is the reason for the difficulty in eradicating retroviruses?
The presence of proviral DNA and cellular reservoirs
What are the two important factors in the achievement of a good virologic response and to contain emergence of resistance?
Drug potency and genetic barrier
What is genetic barrier in the context of HIV treatment?
The type and the number of mutations required by HIV to develop a fully resistant virus
What is interferon and what are its advantages?
A protein that broadens the action spectrum, has low toxicity and modest antigenic properties
What is the effect of combining interferon and ribavirin in treating viral infections?
It improves the duration of virologic response compared to monotherapy
What is a vaccine and what is its purpose?
A body inoculum that stimulates an active immune response against a specific factor
What is herd immunity?
Direct protection from infectious disease that occurs when a large percentage of a population has become immune to an infection
What is the mechanism of action of nucleos(t)ide reverse transcriptase inhibitors?
They arrest the synthesis of viral DNA by reverse transcriptase
Which of the following is an integrase inhibitor?
Dolutegravir
What is the role of gp41 in HIV-1 entry?
Binds to gp120
Which of the following drugs binds to CCR5 to inhibit HIV-1 entry?
Maraviroc
What is the function of integrase in the HIV life cycle?
Mediates the transfer of proviral DNA into the host genome
What is the primary difference between passive and active immunization?
Passive immunization is a short-term immunization achieved by the transfer of antibodies, while active immunization is relatively permanent.
What are the limitations of passive immunization?
It can only be administered at the beginning of an acute infection.
What are the common methods of acquiring passive immunization?
Human or animal blood plasma or serum, pooled human immunoglobulin, and monoclonal antibodies.
What is the purpose of active immunization?
To develop a relatively permanent immune response against pathogens.
What is the risk associated with passive immunization?
Hypersensitivity reactions and serum sickness.
What is the mechanism of action of integrase inhibitors in treating HIV?
They interfere with the strand transfer process of the viral DNA by binding to integrase
How do protease inhibitors prevent the maturation of the viral particle?
By binding to the active site of HIV protease
What is drug resistance in the context of HIV treatment?
The ability of the virus to replicate even in the absence of the drug
What is the new treatment option being offered to people with HIV in England?
A long-acting injection of cabotegravir and rilpivirine
Which of the following is NOT a drug available for the treatment of chronic hepatitis B virus?
Interferon α 2B
What is the most commonly used adjuvant in the production of antibodies from immunized animals?
Both aluminum hydroxide and paraffin oil
What is tetanus?
A disease caused by a bacterium
What is the estimated minimum human lethal dose of tetanospasmin?
2.5 nanograms per kilogram of body weight
Where can C. tetani spores be found?
In soil, intestines and feces of animals, and contaminated heroin
What is the function of tetanolysin?
It is not known
What is the basic cycle of the tetanus vaccination for infants?
Three doses in the first year of life
What is the purpose of the hexavalent vaccine?
To protect against tetanus and other infections
When are the booster doses for tetanus given?
At 6 years and 15 years of age
What is the composition of the vaccine against Hepatitis B?
Purified HBsAg attained from transformed cells of Saccharomyces cerevisiae
How is the vaccine given?
Intramuscularly
What are the ideal characteristics of a good vaccine?
Efficacy, once-a-day administration, no side effects, stability, easy administration, wide availability, low prices
What are the constituents of a vaccine?
Active ingredient, preserving liquid, stabilizers, adjuvants
What are the different routes of administration for vaccines?
Oral, parenteral, intradermal, subcutaneous, intramuscular
What is the disadvantage of vaccines based on whole inactivated organisms?
They elicit little or completely absent cell-mediated immunity
How are vaccines based on attenuated living organisms produced?
By isolating a microorganism of high virulence from a case of severe disease
What is the main goal of antiviral drugs during a pandemic?
To decrease the number of deaths
Which of the following is NOT an ideal characteristic for an antiviral drug?
Carcinogenic
Which of the following infectious diseases does NOT have a drug for treatment?
Zika virus infections
What is an important characteristic of an antiviral drug during a pandemic alert period?
It should prevent the spread of new virus subtypes
Which of the following is NOT a characteristic of an ideal antiviral drug?
Toxic
What is an adjuvant in the context of vaccines?
An agent that modifies the effect of other agents in the vaccine
What are the disadvantages of vaccines based on attenuated living organisms?
They can cause a reactivation of the virulent microorganism
What is a toxoid in the context of vaccines?
A chemical treatment used to suppress the toxicity of a toxin
What is a potential risk of viral vaccines produced using attenuated living organisms?
They are difficult to store at room temperature
What type of response is induced by vaccines based on attenuated living organisms for intracellular microorganisms?
A strong cell-mediated response
What is the difference between the tetravalent and nonavalent vaccines?
The tetravalent vaccine protects against 4 genotypes, while the nonavalent vaccine protects against 9 genotypes
What is the advantage of using vectored vaccines?
They are easy and relatively cheap to make
What is the bivalent vaccine?
It protects against genotypes 16 and 18
What is a vectored vaccine?
A vaccine based on genome modification of an innocuous and weakened microorganism introducing the genic sequence of selected antigen in order to make it express
What is the advantage of using interferon in treating viral infections?
It has a low toxicity and broad action spectrum
What is the goal of vaccination?
To reduce the circulation of a pathogen in unvaccinated individuals
What is herd immunity?
A form of indirect protection from infectious disease
What is the difference between the inactivated and weakened live polio vaccines?
The weakened live vaccine is orally givable
What is the sustained virological response rate of interferon and ribavirin therapy?
More than 50%
What are the ideal characteristics of a good vaccine?
No side effects
What are the constituents of a vaccine?
Preservatives, stabilizers, and antibiotics
Which of the following is NOT a route of administration for vaccines?
Topical
What is the disadvantage of vaccines based on whole inactivated organisms?
They need booster doses
How are vaccines based on attenuated living organisms produced?
By using chemical mutagenesis
What is passive immunization?
A short-term immunization achieved by transfer of antibodies
What are the methods of acquisition for passive immunization?
Human or animal blood plasma or serum, pooled human immunoglobulin, and monoclonal antibodies
What is the duration of immunity derived from passive immunization?
A few weeks or months
When is passive immunization used?
To provide immediate protection without developing memory
What are the potential risks associated with passive immunization?
Hypersensitivity reactions and serum sickness
What is the main function of neuraminidase inhibitors in treating influenza infections?
They interfere with a specific function essential for virus replication
Which of the following drugs is an inhibitor of neuraminidase?
Zanamivir
What is the function of M2 protein in the influenza virus life cycle?
To act as protonic pumps
How many drugs have been approved to treat influenza infections?
8
Why is it more complex to employ drugs against viruses than bacteria?
Viruses replicate exclusively in host cells
What is the mechanism of action of rimantadine against influenza virus?
It targets the M2 viral proton pump
What is the primary target of anti-herpes virus drugs?
Viral DNA polymerase
What is the main difference between acyclovir and guanosine?
Acyclovir lacks a 3' hydroxyl group
What is the mechanism of action of ganciclovir against cytomegalovirus?
It inhibits viral DNA polymerase
What is the goal of HIV treatment with ART?
To control the symptoms of HIV
What is the main reason why HBV infection is not curable?
The virus genome persists and is archived inside hepatocytes
What is the issue with stop codons and deletions in the HBsAg gene?
They lead to the production of truncated HBsAg even with suppressive therapy
What makes HCV curable?
The viral genome is not archived into the genome of infected cells
What is the mechanism of action of ribavirin?
It inhibits the production of viral nucleic acids
What is the mechanism of action of interferon against HCV?
It activates the immune system to fight the virus
What is the difference between the Bivalent and Nonavalent vaccines?
The Nonavalent vaccine covers more genotypes than the Bivalent vaccine
What is the advantage of using vectored vaccines?
They are easy and relatively cheap to make
Which vaccine covers the most genotypes?
Nonavalent
What is a vectored vaccine?
A vaccine based on genome modification of an innocuous and weakened microorganism
Which vector is commonly used for various vaccines?
Adenovirus vector
What is the mechanism of action of integrase inhibitors in HIV treatment?
They interfere with the strand transfer process of the viral DNA by binding to the active site of integrase
What is the consequence of amino acid substitutions in the HIV protease enzyme?
They reduce the affinity of protease inhibitors for the enzyme
What is the primary advantage of the long-acting injection for HIV treatment?
It is easier to administer than daily pills
Which drugs are available for the treatment of chronic hepatitis B virus?
Lamivudine and Entecavir
What is the mechanism of action of immune-modulant drugs in hepatitis B treatment?
They modify the host immune response to the virus
What is the main goal of therapy and prophylaxis with antiviral drugs during a pandemic?
To decrease the number of deaths
Which of the following is NOT a characteristic of an ideal antiviral drug?
Toxic
Which of the following human infectious diseases does NOT have drugs for treatment?
Hepatitis A infections
What are the three main goals of therapy and prophylaxis with antiviral drugs during a pandemic?
To decrease morbidity, decrease mortality, and prevent the spread of new virus subtypes
Which of the following is NOT a characteristic of an ideal antiviral drug?
Water-soluble
What is the primary goal of ART (antiretroviral therapy) in individuals living with HIV?
Reduce HIV-associated morbidity and prolong the duration and quality of survival
What makes retroviruses so difficult to eradicate?
They integrate their DNA into the host cell's genome
What is genetic barrier in the context of HIV treatment?
The type and the number of mutations required by HIV to develop a fully resistant virus
What is the mechanism of action of integrase inhibitors in HIV treatment?
They prevent the integration of viral DNA into the host cell genome
What are the two important factors in achieving a good virologic response and containing emergence of resistance in HIV treatment?
The patient's adherence to the treatment regimen and the potency and genetic barrier of the drugs used
What is the basic cycle of the tetanus vaccination for infants?
Three doses of vaccine within the first year of life
What is the purpose of the hexavalent vaccine?
To prevent tetanus and several other infections
When are the booster doses for tetanus given?
At 6 and 15 years of age
What are subunit vaccines?
Vaccines that consist of purified bacterial or viral components
What is the composition of the vaccine against human papillomavirus (HPV)?
Virus-like particles without pathogen properties
What is the mechanism of action of nucleoside reverse transcriptase inhibitors?
They arrest the synthesis of viral DNA by reverse transcriptase
What is the mechanism of action of non-nucleoside reverse transcriptase inhibitors?
They affect the flexibility of reverse transcriptase, blocking its ability to synthesize DNA
What is the function of integrase in the HIV life cycle?
To transfer the proviral DNA into the host genome
What is the mechanism of action of enfuvirtide?
It binds to gp41 to inhibit HIV-1 entry
What is the mechanism of action of integrase inhibitors?
They block the ability of integrase to transfer proviral DNA into the host genome
What is the most commonly used adjuvant in the production of antibodies from immunized animals?
Aluminum hydroxide
What is tetanus?
A bacterial infection caused by Clostridium tetani
What is the estimated minimum human lethal dose of tetanospasmin?
2.5 nanograms per kilogram of body weight
What are the clinical manifestations of tetanus?
Generalized rigidity and convulsive spasms of skeletal muscles
What is the function of tetanolysin?
It is not known with certainty
What is the function of neuraminidase in the influenza virus life cycle?
It releases viral particles from infected cells
Which of the following drugs is administered via inhalation for the treatment of influenza infections?
Zanamivir
What is the target of neuraminidase inhibitors in anti-influenza drugs?
The activity of neuraminidase
What is the role of the M2 protein in the influenza virus life cycle?
It acts as a protonic pump
How do neuraminidase inhibitors act as competitive inhibitors?
They mimic the structure of sialic acid residues
What is the mechanism of action of nucleos(t)ide reverse transcriptase inhibitors?
They arrest the synthesis of viral DNA by reverse transcriptase
What is the function of integrase in the HIV life cycle?
It mediates the transfer of proviral DNA into the host genome
What is the mechanism of action of non-nucleoside reverse transcriptase inhibitors?
They affect the flexibility of the reverse transcriptase enzyme
Which drug binds to CCR5 to inhibit HIV entry?
Maraviroc
Which drug binds to gp41 to inhibit HIV entry?
Enfuvirtide
What is the mechanism of action of amantadine and rimantadine in inhibiting influenza virus penetration?
Blocking the M2 viral proton pump
What is the target of anti-herpes virus drugs?
Viral DNA polymerase
What is the specific use of acyclovir in the treatment of viral infections?
Herpes simplex virus, chickenpox virus, Epstein-Barr virus, and herpes encephalitis in immuno-compromised patients
What is the mechanism of action of ganciclovir in inhibiting viral replication?
Inhibiting the viral DNA polymerase
What is the goal of HIV treatment with antiretroviral therapy (ART)?
To reduce the viral load to undetectable levels
What is the mechanism of action of integrase inhibitors in treating HIV?
They interfere with the strand transfer process of the viral DNA by binding to the active site of integrase
What is the consequence of amino acid substitutions that emerge in the substrate-binding domain of the HIV protease enzyme?
They reduce the affinity of the protease inhibitors for the enzyme
What is the new long-acting injection that is being offered to people with HIV in England?
Cabotegravir and rilpivirine injections
Which of the following is a nucleoside RT inhibitor for the treatment of chronic hepatitis B virus?
Adefovir
What is the main consequence of drug resistance in HIV treatment?
The virus continues to replicate despite the presence of the drug
What is the main goal of antiviral therapy and prophylaxis during a pandemic?
To reduce morbidity and mortality
Which of the following is NOT an infectious disease for which there are drugs available for treatment?
Ebola virus infections
What are the ideal characteristics of an antiviral drug?
Water-soluble, chemically and metabolically stable, and easily absorbed
Which of the following infectious diseases has a drug available for treatment?
Varicella-zoster virus infections
What is the main characteristic of an ideal antiviral drug?
Water-soluble, chemically and metabolically stable, and easily absorbed
What is an adjuvant in the context of vaccines?
A pharmacological or immunological agent that modifies the immune response to a vaccine
Which of the following is a disadvantage of vaccines based on attenuated living organisms?
They can cause a reactivation of the virulent microorganism
What is the difference between a vaccine based on inactivated microorganisms and a vaccine based on attenuated living organisms?
Vaccines based on attenuated living organisms can cause a reactivation of the virulent microorganism
What is a toxoid in the context of vaccines?
A chemical treatment used to suppress toxicity in toxins
What is a disadvantage of vaccines based on attenuated living organisms?
They can cause a reactivation of the virulent microorganism
What is the primary disadvantage of vaccines based on whole inactivated organisms?
They elicit little to no cell-mediated immunity
Which of the following is NOT a constituent of a vaccine?
Enzymes
What is the primary advantage of vaccines based on attenuated living organisms?
They elicit a strong cell-mediated immune response
Which of the following is NOT a route of administration for vaccines?
Intravenous
What is the purpose of adjuvants in vaccines?
To stimulate the immune system
What is the advantage of using a combination of interferon and ribavirin for HCV treatment?
It increases the duration of virologic response
Which diseases have the potential to be eradicated by a vaccine?
Measles, rubella, and smallpox
What is herd immunity?
A measure of protection for individuals who are immune
What is a vaccine?
A body inoculum that stimulates an active immune response against a specific factor
What is the difference between the vaccines developed by Jonas Salk and Albert Sabin for poliomyelitis?
Sabin's vaccine was orally givable, while Salk's was inactivated
What is an advantage of vaccines based on attenuated living organisms?
They induce a strong cell-mediated response
What is a disadvantage of vaccines based on toxoids?
The detoxification process is reversible
What is the purpose of an adjuvant in a vaccine?
To modify the effect of other agents
What is a potential risk of vaccines based on attenuated living organisms?
They may cause the reactivation of the virulent microorganism
What is the temperature range required for storing vaccines based on toxoids?
Preferably 4°C
What makes HBV infection not curable?
The persistence of HBV genome (cccDNA) inside the hepatocytes
What is the difference between HCV and HBV in terms of viral genome replication?
HCV replication occurs only in cytoplasm, while HBV replication occurs in both cytoplasm and nucleus
What is the mechanism of action of ribavirin?
It inhibits the replication of several RNA and DNA viruses
What is the clinical relevance of stop codons and deletions in HBsAg?
They increase the risk of liver cancer even with fully suppressive therapy
What is the difference between HIV and HBV in terms of curability?
HBV infection is curable, while HIV infection is not curable
What is the causative agent of tetanus?
Clostridium tetani
What is the estimated minimum lethal dose of tetanospasmin for a 70-kg human?
2.5 nanograms
What is the most commonly used adjuvant in the production of antibodies from immunized animals?
Aluminum hydroxide
What is the function of tetanolysin produced by Clostridium tetani?
It is not known with certainty
Where are the spores of Clostridium tetani commonly found?
In soil and in the intestines and feces of various animals
What is the recommended basic cycle of the tetanus vaccination for infants?
Three doses of vaccine in the first year
What is the composition of the hexavalent vaccine?
Protects against tetanus, diphtheria, poliomyelitis, hepatitis B, pertussis and Haemophilus influenzae type infections B
When are the booster doses for tetanus given?
At 6 years and 15 years of age
What is the recommended interval for further boosters of the tetanus vaccine for adults?
Every 10 years
What is the method of delivery for the tetanus vaccine?
Intramuscular
What is the primary goal of antiretroviral therapy (ART) for individuals living with HIV?
Reduce HIV-associated morbidity and prolong survival
What is the reason why HIV-1 cannot be eliminated from infected patients even with effective HAART?
HIV-1 quickly returns when therapy is stopped
What is the role of genetic barrier in achieving a good virologic response and preventing emergence of resistance?
It determines the likelihood of clinically meaningful resistance
What is the mechanism by which retroviruses replicate in host cells?
Retroviruses synthesize a DNA copy of their genome after entry into the host cell
What types of immunization are mentioned in the text?
Active and passive
What is the difference between passive and active immunization?
Passive immunization provides short-term protection and does not develop memory, while active immunization is relatively permanent
What are the methods of acquisition for passive immunization?
Natural maternal antibodies, antitoxins, and immune globulins
What is the duration of immunity derived from passive immunization?
A few weeks or months
When is passive immunization used?
When there is a high risk of infection and insufficient time for the body to develop its own immune response, or to reduce the symptoms of ongoing or immunosuppressive diseases
What is the difference between the Bivalent and Nonavalent HPV vaccines?
Bivalent includes genotypes 16 and 18, while Nonavalent includes genotypes 6, 11, 16, 18, 31, 33, 45, 52, and 58
What is the advantage of using vectored vaccines?
Vectored vaccines can be easily and relatively cheaply produced
Which genotypes are included in the Tetravalent HPV vaccine?
6, 11, 16, and 18
What is a vectored vaccine?
A vaccine that uses a genetically modified virus to introduce genetic material from the pathogen being targeted
Which HPV vaccine includes the most genotypes?
Nonavalent
What is the difference between passive and active immunization?
Passive immunization involves the transfer of antibodies while active immunization involves natural maternal antibodies.
What is the purpose of passive immunization?
To reduce the symptoms of ongoing or immunosuppressive diseases.
What is the duration of immunity derived from passive immunization?
A few weeks or months.
What are the potential risks associated with passive immunization?
Hypersensitivity reactions.
What is the method of acquisition for passive immunization?
Transfer of antibodies.
What is the mechanism of action of nucleoside reverse transcriptase inhibitors (NRTIs)?
They arrest the synthesis of viral DNA by reverse transcriptase
Which of the following is NOT a nucleoside reverse transcriptase inhibitor?
Raltegravir
What is the function of integrase in the HIV life cycle?
It mediates the transfer of the proviral DNA into the host genome
Which drug binds to CCR5 to inhibit HIV entry?
Maraviroc
What is the mechanism of action of non-nucleoside reverse transcriptase inhibitors (NNRTIs)?
They affect the flexibility of reverse transcriptase, blocking its ability to synthesize DNA
What is the mechanism of action of amantadine and rimantadine in inhibiting influenza virus penetration?
Blocking the M2 viral proton pump
Which of the following is NOT one of the anti-herpes virus drugs mentioned in the text?
Zidovudine
What is the primary target of anti-herpes virus drugs like acyclovir?
Viral DNA polymerase
What is the structural similarity between acyclovir and guanosine?
Acyclovir is an analogue of guanosine
What is the mechanism of action of ganciclovir against cytomegalovirus?
Inhibiting viral DNA polymerase through a viral kinase encoded by gene UL97
What is the advantage of interferon as a treatment for viral infections?
Low toxicity and modest antigenic properties
What is the benefit of combining interferon and ribavirin in the treatment of HCV?
It improves sustained virological response compared to monotherapy
Which diseases have the potential to be eradicated by a vaccine?
Measles, rubella, HBV, smallpox, polio
What is the goal of vaccination?
To reduce disease in both vaccinated and unvaccinated individuals
What is herd immunity?
The immunity of a population to a pathogen
What is the purpose of antiviral drugs during a pandemic alert period?
To reduce the number of individuals at risk of getting a disease
Which of the following diseases does NOT have drugs for treatment according to the text?
Zika virus infections
What are the characteristics of an ideal antiviral drug according to the text?
Water-soluble, chemically and metabolically stable, easily absorbed
What is the target of neuraminidase inhibitors in anti-influenza drugs?
Release of new virus particles from infected cells
What is the purpose of prophylaxis with antiviral drugs during a pandemic alert period?
To increase the number of individuals at risk of getting a disease
What is the causative agent of tetanus?
A bacterium
What is the function of tetanolysin, one of the exotoxins produced by Clostridium tetani?
It is not known with certainty
What is the estimated minimum human lethal dose of tetanospasmin, the neurotoxin produced by Clostridium tetani?
2.5 nanograms per kilogram of body weight
Which of the following animals may harbor Clostridium tetani?
Cats
What are the two most commonly used adjuvants in the production of antibodies from immunized animals?
Aluminum hydroxide and paraffin oil
What is the mechanism of action of integrase inhibitors in HIV treatment?
They interfere with the strand transfer process of viral DNA by binding to integrase.
What is the consequence of amino acid substitutions that emerge in the substrate-binding domain of HIV protease?
They reduce the affinity of protease inhibitors for the enzyme.
What is the primary goal of long-acting injection treatment for HIV?
To replace daily pills with a more convenient treatment.
What is the difference between nucleoside RT inhibitors and acyclic nucleoside phosphonate analogues RT inhibitors?
Nucleoside RT inhibitors act as chain terminators, while acyclic nucleoside phosphonate analogues RT inhibitors inhibit viral DNA synthesis.
What is the function of immune-modulant drugs in the treatment of chronic hepatitis B virus?
To stimulate the immune system to fight the virus.
What is the main goal of antiretroviral therapy (ART) for HIV infection?
Reduce HIV-associated morbidity
Why is it difficult to eradicate retroviruses like HIV?
Proviral DNA and cellular reservoirs prevent eradication
What is the significance of drug potency and genetic barrier in HIV treatment?
Both drug potency and genetic barrier are important
When should antiretroviral therapy (ART) be initiated for individuals living with HIV?
Regardless of WHO clinical stage and CD4 cell count
What is the likelihood of clinically meaningful resistance if a drug has a low genetic barrier?
High likelihood
What is the difference between the Bivalent and Nonavalent vaccines for HPV?
Nonavalent covers more genotypes than Bivalent
What is a potential advantage of using vectored vaccines?
They are relatively easy and cheap to make
What is the Tetravalent vaccine for HPV?
Covers genotypes 6, 11, 16, and 18
What is a vectored vaccine?
A vaccine based on genome modification of a microorganism
Which virus vector is commonly used for various vaccines?
Adenovirus vector
What is a disadvantage of vaccines based on attenuated living organisms?
There is a possibility of reactivation of the virulent microorganism
What is an adjuvant in a vaccine?
A pharmacological or immunological agent that modifies the immune response to the vaccine
What is a toxoid vaccine?
A vaccine based on a toxin whose toxicity has been suppressed by chemical treatment
What is a disadvantage of vaccines based on inactivated microorganisms?
Their effectiveness is generally lower than that of vaccines based on attenuated living organisms
What is a disadvantage of vaccines based on living organisms?
There is a possibility of reactivation of the virulent microorganism
What are the constituents of a vaccine?
Active ingredient, preserving liquid, stabilizers, antibiotics, adjuvants
Which route of administration is NOT used for vaccines?
Intravenous
What is the basic cycle of the tetanus vaccination for infants?
Three doses administered in the first year of life
Which type of vaccine elicits little or completely absent cell-mediated immunity?
Vaccines based on whole inactivated organisms
How are vaccines based on attenuated living organisms produced?
By isolating a microorganism of low virulence from a case of mild disease
Which infections are prevented by the hexavalent vaccine?
Tetanus, diphtheria, poliomyelitis, hepatitis B, pertussis, and Haemophilus influenzae type infections B
Which of the following diseases can be prevented by a vaccine based on whole inactivated organisms?
Whooping cough (pertussis)
How many booster doses are given for the tetanus vaccination?
Two booster doses
Which type of vaccine is associated with a lower risk of adverse reactions?
Subunit vaccines
What is the composition of the vaccine against Hepatitis B?
Purified HBsAg attained from transformed cells of Saccharomyces cerevisiae
What is the function of neuraminidase in the influenza virus life cycle?
It cleaves sialic acid residues on glycoproteins, allowing the entry of the virus into target cells and the release of viral particles from infected cells
What is the mechanism of action of neuraminidase inhibitors?
They mimic the structure of sialic acid residues and act as competitive inhibitors of the neuraminidase enzyme
What is the target of M2 protein inhibitors?
The M2 protein itself
What is the difference between Zanamivir and Oseltamivir?
Zanamivir is administered via inhalation, while Oseltamivir is administered per oral suspension
Why is it more complex to develop drugs against viruses compared to bacteria?
Viruses can replicate exclusively in host cells of the organism
What is the mechanism of action of Ribavirin against viral replication?
It inhibits the inosine monophosphate deidrogenase enzyme
Why is HBV infection not curable?
HBV genome persists and is archived inside the hepatocytes
What is the consequence of stop codons and deletions in S antigen in HBV infection?
The production of truncated HBsAg can still go on even if the patient receives a fully suppressive therapy
What is the main difference between HCV and HBV in terms of curability?
HCV is curable, while HBV infection is not curable
What is the mechanism of action of Interferon against HCV infection?
It stimulates the immune system to attack the virus
What is the mechanism of action of integrase inhibitors in HIV treatment?
They interfere with the strand transfer process of the viral DNA by binding to integrase
What is the consequence of amino acid substitutions that emerge in the substrate-binding domain of the HIV protease?
They reduce the affinity of integrase inhibitors for the enzyme
What is drug resistance in the context of HIV treatment?
The ability of the virus to replicate despite the presence of the drug
What is the new long-acting injection being offered to people with HIV in England?
Two separate injections of cabotegravir and rilpivirine every two months
What is the mechanism of action of protease inhibitors in HIV treatment?
They impede the maturation of the viral particle
What is the mechanism of action of amantadine and rimantadine in inhibiting influenza virus penetration?
They inhibit the viral proton pump M2
What is the primary target of anti-herpes virus drugs like acyclovir?
Viral DNA polymerase
What is the difference between acyclovir and guanosine?
Acyclovir lacks a 3' hydroxyl group
What is the difference between the affinity of acyclovir for viral thymidine kinase and cellular kinases?
Acyclovir has 200 times higher affinity for viral thymidine kinase
What is the main difference between the activation of acyclovir and gancyclovir?
Acyclovir is activated by a viral kinase encoded by the gene UL97
What is the mechanism of action of interferon?
It promotes virus resistance by induction
What is the advantage of using a vaccine?
Reduction / absence of disease in individuals
What is the difference between the vaccines developed by Jonas Salk and Albert Sabin against poliomyelitis?
Salk's vaccine was inactivated, while Sabin's was weakened live
What is herd immunity?
Indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection
What is the effect of the combination of interferon and ribavirin on HCV treatment?
Improves the duration of virologic response and allows to achieve a sustained virological response in 50% of the cases
What is the primary goal of therapy and prophylaxis with antiviral drugs during pandemics?
Reduce morbidity and mortality
Which of the following is NOT a characteristic of an ideal antiviral drug?
Toxic
Which of the following human infectious diseases currently has drugs for treatment?
Influenza virus
What is a desirable characteristic of an antiviral drug?
Metabolically stable
What is the purpose of prophylaxis with antiviral drugs during pandemics?
Protect people who play key roles in managing the response to pandemic
What is the difference between HBV and HCV replication?
HBV genome is archived inside the hepatocytes
What is the consequence of stop codons and deletions in HBsAg in HBV infection?
They can lead to the production of truncated HBsAg even with suppressive therapy
What is the mechanism of action of ribavirin in inhibiting viral replication?
Non-competitive inhibition of RNA polymerase
What is the consequence of drug resistance mutations in the RT in HBV infection?
They correspond to stop codons in the HBsAg
What is the function of interferon in HCV infections?
Activates the immune system of the organism
What are the types of immunization mentioned in the text?
Passive and active immunization
What is passive immunization?
A short-term immunization achieved by the transfer of antibodies
What are the methods of acquisition for passive immunization?
Natural maternal antibodies, antitoxins, and immune globulins
What is the duration of immunity derived from passive immunization?
A few weeks or months
When is passive immunization used?
When there is a high risk of infection and insufficient time for the body to develop its own immune response
What is the mechanism of action of nucleoside reverse transcriptase inhibitors (NTRIs)?
They arrest the synthesis of viral DNA by reverse transcriptase
What is the function of integrase in the HIV life cycle?
It mediates the transfer of proviral DNA into the host genome
Which drug binds to CCR5 to inhibit HIV-1 entry?
Maraviroc
What is the mechanism of action of non-nucleoside reverse transcriptase inhibitors (NNRTIs)?
They affect the flexibility of reverse transcriptase, blocking its ability to synthesize DNA
What is the function of gp120 in the HIV-1 entry process?
It binds to CD4 to facilitate HIV-1 entry
What are the key treatment goals for individuals living with HIV?
Suppress plasma HIV RNA
What is the mechanism of action of retroviruses that makes them difficult to eradicate?
Integration of the viral DNA into the host cell's genome is an essential step in the viral replication cycle, making eradication difficult
What is the significance of genetic barrier in achieving a good virologic response and preventing emergence of resistance?
It determines the number of mutations required by HIV to develop a fully resistant virus
What is the significance of drug potency in the treatment of HIV infection?
It determines the potency of the drug against HIV
Is it necessary to initiate ART in all individuals living with HIV?
Yes, regardless of WHO clinical stage and at any CD4 cell count
What are the ideal characteristics of a good vaccine?
Stability
What are the constituents of a vaccine?
Active ingredient, preserving liquid, and stabilizers
What is the route of administration for a vaccine?
Intramuscular
What is the disadvantage of vaccines based on whole inactivated organisms?
Completely absent cell-mediated immunity
How are vaccines based on attenuated living organisms produced?
By performing multiple cultures to decrease virulence but not antigenicity
What is the causative agent of tetanus?
Clostridium tetani
What is the most commonly used adjuvant in the production of antibodies from immunized animals?
Aluminum hydroxide
What are the clinical manifestations of tetanus?
Muscle stiffness and convulsive spasms of skeletal muscles
What is the estimated minimum human lethal dose of tetanospasmin?
175 nanograms per kilogram of body weight
What is the function of tetanolysin?
It is not known with certainty
What is the primary disadvantage of vaccines based on attenuated living organisms?
They have the possibility of reactivating the virulent microorganism
What is the role of an adjuvant in vaccines?
To modify the effect of other agents and boost the immune response
Which of the following diseases can be prevented by a vaccine based on a toxoid?
Tetanus
What is the disadvantage of vaccines based on inactivated microorganisms?
They induce a weaker cell-mediated response
What is the storage requirement for vaccines based on attenuated living organisms?
At least -4°C, preferably -80°C
What is the main function of antiviral drugs?
To interfere with a specific function essential for virus replication
What makes it difficult to employ drugs against viruses compared to bacteria?
Viral ability to replicate exclusively in host cells
Which of the following is a target of anti-influenza drugs?
Neuraminidase enzyme
What is the function of neuraminidase in the influenza virus life cycle?
Cleaves sialic acid residues on glycoprotein to allow entry and release of virus
How do neuraminidase inhibitors work?
They block the activity of neuraminidase by mimicking the structure of sialic acid residues
What is the difference between Zanamivir and Oseltamivir?
Zanamivir is administered via inhalation, Oseltamivir is administered per oral suspension
What is the function of M2 protein in the influenza virus life cycle?
Acts as a protonic pump to determine acidification of the endocytic vesicle
What is the recommended cycle for tetanus vaccination in infants?
Three doses of vaccine in the first year of life
What is the purpose of the booster doses for tetanus vaccination?
To maintain an adequate level of immunity
What other infections can the hexavalent vaccine protect against, in addition to tetanus?
Diphtheria and poliomyelitis
What is the composition of the vaccine against Hepatitis B?
Purified viral components
What is the mechanism of protection of the vaccine against human papillomavirus (HPV)?
It provides type-specific protection against relevant HPV genotypes
What is the mechanism of action of protease inhibitors in treating HIV?
They inhibit the catalytic activity of the HIV protease
What is drug resistance in the context of HIV treatment?
The ability of the virus to replicate despite the presence of the drug
What is the target of reverse transcriptase inhibitors in treating chronic hepatitis B virus?
The viral DNA polymerase
What is the mode of delivery for the new long-acting injection for HIV treatment?
Subcutaneous injection
What is the difference between the Nonavalent and Tetravalent vaccines?
The Nonavalent vaccine targets more genotypes of HPV than the Tetravalent vaccine
What is a vectored vaccine?
A vaccine made by modifying an innocuous microorganism to express a selected antigen
What is the advantage of using vectored vaccines?
They are relatively easy and cheap to make
Which genotypes of HPV are targeted by the Bivalent vaccine?
Genotypes 16 and 18
What is the adenovirus vector used for in vaccines?
It can be used for various vaccines
What are the ideal characteristics of a good vaccine?
Stability
Which of the following is NOT a constituent of a vaccine?
Antibiotics
What is the route of administration for a vaccine?
Oral
What is the disadvantage of vaccines based on whole inactivated organisms?
Elicits strong cell-mediated immunity
How are vaccines based on attenuated living organisms produced?
By chemical mutagenesis
What types of immunization are mentioned in the text?
Active and passive
What is the difference between active and passive immunization?
Active immunization provides immediate protection and passive immunization develops memory
What is an example of a method of acquisition for passive immunization?
Immune globulins
What is the limitation of immunity derived from passive immunization?
It lasts for a few weeks or months
When is passive immunization used?
When there is a high risk of infection and insufficient time for the body to develop its own immune response
What is the advantage of interferon in treating viral infections?
It has a low toxicity and broad action spectrum
What is the difference between Jonas Salk and Albert Sabin's polio vaccines?
Salk's vaccine was inactivated while Sabin's was orally givable
What is herd immunity?
Indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection
What is the primary advantage of vaccines?
They reduce or eliminate disease in individuals
What is the effect of the combination of interferon and ribavirin on HCV treatment?
It improves the duration of virologic response compared to interferon alone
What is the primary goal of therapy and prophylaxis with antiviral drugs during a pandemic?
To decrease the number of deaths
Which of the following diseases can be treated with drugs according to the text?
Hepatitis C
What are some characteristics of an ideal antiviral drug according to the text?
Water-soluble, chemically and metabolically stable, easily absorbed
What is the goal of prophylaxis with antiviral drugs during a pandemic?
To cause mutations in the virus
Which of the following viruses does NOT have drugs available for treatment according to the text?
Ebola virus
What is an advantage of vaccines based on attenuated living organisms?
They induce a strong cell-mediated response
What is a disadvantage of vaccines based on attenuated living organisms?
They pose a risk of reactivating the virulent microorganism
What is the function of an adjuvant in a vaccine?
To modify the effect of other agents
What is a disadvantage of vaccines based on toxoids?
The detoxification process is reversible
What is the main advantage of vaccines based on inactivated microorganisms?
They are generally more effective than attenuated living organism vaccines
What is the function of neuraminidase in the influenza virus life cycle?
It cleaves sialic acid residues on glycoprotein, allowing entry of virus into target cells
Which of the following is a target of anti-influenza drugs?
All of the above
How do neuraminidase inhibitors work?
They block the activity of neuraminidase
Which of the following drugs is administered via inhalation for the treatment of influenza?
Zanamivir
What is the function of the M2 protein in the influenza virus life cycle?
It determines an acidification of the endocytic vesicle, allowing release of viral genome into the cytoplasm
What is the primary goal of antiretroviral therapy (ART) in individuals living with HIV?
To restore and preserve immunologic function
What is the role of integrase inhibitors in HIV treatment?
To prevent emergence of resistance
What is the genetic barrier of a drug in HIV treatment?
The type and number of mutations required by HIV to develop a fully resistant virus
What is the consequence of stopping highly active antiretroviral therapy (HAART)?
HIV-1 returns rapidly
Why is it difficult to eradicate retroviruses like HIV?
They form viral reservoirs in the host cell's genome
What is the basic cycle of the tetanus vaccination for infants?
Three doses to be administered in the third, fifth and twelfth months of life
What is the composition of the hexavalent vaccine?
Tetanus, diphtheria, poliomyelitis, hepatitis B, pertussis, and Haemophilus influenzae type infections B
When are booster doses for tetanus vaccination given?
At 6 years of age and around 15 years of age
Which type of vaccines have better safety profiles than others?
Subunit vaccines
What is the composition of the vaccine against human papillomavirus (HPV)?
Human papillomavirus L1 capsid protein
What is the primary difference between HBV and HCV replication?
HBV genome is archived inside the hepatocytes
What is the mechanism of action of Ribavirin in inhibiting viral replication?
Inhibition of inosine monophosphate deidrogenase enzyme
What is the clinical relevance of stop codons and deletions in HBsAg?
They increase the risk of liver cancer even if viremia is undetectable
What is the mechanism of action of Interferon in inhibiting HCV replication?
Activation of host defense mechanisms
Why is HBV infection not curable?
HBV genome is archived inside the hepatocytes
What is the mechanism of action of amantadine and rimantadine in inhibiting influenza virus penetration?
They prevent the virus from entering the host cell
What is the primary target of anti-herpes virus drugs?
Viral thymidine kinase
Which of the following drugs is NOT used for the treatment of herpes simplex virus?
Ganciclovir
What is the goal of HIV treatment with ART?
To suppress viral replication to undetectable levels
What is the difference between the mechanism of action of acyclovir and ganciclovir?
Acyclovir is activated by a viral kinase, while ganciclovir is activated by a thymidine kinase
What is the mechanism of action of Fostemsavir in inhibiting HIV-1 entry?
Binds to gp120
Which of the following drugs is a non-nucleoside reverse transcriptase inhibitor?
Efavirenz
What is the function of integrase in the HIV life cycle?
Integrates HIV DNA into the host chromosome
Which of the following drugs inhibits the synthesis of viral DNA by reverse transcriptase?
Emtricitabine
What is the mechanism of action of Non-nucleoside reverse transcriptase inhibitors?
Binds to a hydrophobic pocket near the catalytic domain of reverse transcriptase to block its ability to synthesize DNA
What is the most commonly used adjuvant in the production of antibodies from immunized animals?
Aluminum hydroxide
What is the causative agent of tetanus?
Clostridium tetani
What is the estimated minimum lethal dose of tetanospasmin for a 70-kg human?
175 nanograms
What is the function of tetanolysin produced by Clostridium tetani?
Not known with certainty
Where are the spores of Clostridium tetani found?
In soil, intestines and feces of various animals, and on skin surfaces
What are the genotypes covered by the Nonavalent vaccine?
Genotypes 6, 11, 16, 18, 31, 33, 45, 52, 58
Which of the following vaccines has the lowest number of covered genotypes?
Bivalent (Cervarix)
What is the advantage of using vectored vaccines?
They are relatively easy and cheap to make
What is the adenovirus vector used for?
To produce all vectored vaccines
What is the mechanism of vectored vaccines?
They are based on genome modification of a pathogenic microorganism
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