Routine Vaccines and Hepatitis B

Routine Vaccines

• Routine vaccination is a critical preventive medical strategy.
• Concerns remain about vaccine efficacy, safety, and duration of protection.
• Important factors include the patient's age, underlying medical conditions, disease burden, vaccine efficacy, adverse reactions, and official recommendations.
• Vaccine-preventable diseases (VPDs) like Haemophilus influenzae type b (Hib) are now rarely encountered, but others, like pertussis, persist.

Hepatitis B Vaccine

• Five Hepatitis B vaccines are available in the US.
• Engerix-B and Recombivax HB, are monovalent vaccines given in a three-dose series at 0, 1-2, and 6 months.
• Pediarix, a pentavalent vaccine, is given at 2, 4, and 6 months (maximum age 6 years).
• Heplisav-B is given at 0 and 1 month, minimum age of 18 years.
• Twinrix, a bivalent vaccine, is given at 0, 1, and 6 months, minimum age of 18 years.
• All children must be immunized against HBV. High-risk adults, like those with diabetes or hepatitis C, or with travel or workplace risks, should also be vaccinated.
• Hepatitis B surface antigen (HBsAg) has been found on various objects, including in saliva, indicating transmission potential.
• HepB vaccine efficacy is high, with over 95% seroconversion after the third dose.
• Preterm infants weighing less than 2 kg should delay vaccination until at least one month of age or hospital discharge unless the mother is HBsAg positive or has unknown HBsAg status. In such cases, HepB should be administered within 12 hours of birth.

Hepatitis A Vaccine

• All infants should get two doses of hepatitis A vaccine (HepA) at ages 12-15 and 18-21 months.
• Side effects are localized swelling and redness.
• Hepatitis A is not a benign disease.
• Anyone wanting protection should be vaccinated at 0 and 6 months with HepA.

Pertussis Vaccine

• Waning immunity, changes in pertussis proteins, and disease perpetuation are factors.
• Most pertussis-related hospitalizations and deaths happen in infants too young to be fully vaccinated.
• Transmission occurs through respiratory droplets and by contact with contaminated objects.
• Susceptible individuals become infected following exposure, and contagions last for 1-3 weeks.
• Intense paroxysmal cough and malaise can last for months.
• Complications include pneumonia and seizures.
• Encephalopathy (which can cause permanent brain damage) occurs in about 1% of cases.

Adverse Reactions

• Minor adverse reactions to DTaP/Tdap vaccinations include injection site edema, fever, and fussiness.
• Previous reports of uncommon adverse reactions with DTap are not now considered connected to the vaccine.
• Anaphylactic reaction to DTaP is a contraindication for further doses.
• Limb swelling and abscesses have also been reported.

Recommendations for Pertussis Vaccine

• All children are vaccinated at 2, 4, and 6 months.
• Booster doses are given at 15-18 months and 4-6 years.
• Four doses are sufficient if the fourth dose is given after the fourth birthday.
• DTaP vaccines have efficacy rates ranging from 80 to 89%.

Diphtheria and Tetanus

• Vaccination against diphtheria and tetanus is critical.
• Routine vaccination includes five DTaP doses during childhood, one Tdap in adolescence, and periodic Td or Tdap boosters every 10 years.

Pneumococcal Conjugate Vaccine

• Prior to the introduction of the vaccine, Streptococcus pneumoniae caused 17,000 cases of invasive disease annually in the US, including 200 deaths among children <5 years.
• This gram-positive diplococcus caused invasive disease (bacteremia, meningitis, or infection in a normally sterile site.)
• The pathogen spreads via respiratory droplets.
• This vaccine significantly reduced the incidence of pneumococcal disease.

Rationale for Vaccination (Pneumococcal)

• Two vaccines, PPSV23 (23-valent polysaccharide) and PCV13 (13-valent conjugate), protect against pneumococcus.
• PCV13 induces more robust, long-lasting immunity.
• PPSV23 does not elicit long-lasting immunity and isn't effective in younger children.
• The use of PCV13 reduces nasopharyngeal carriage rates and transmission.
• PCV13 provides herd immunity, protecting unvaccinated adults.

Recommendations (Pneumococcal)

• Recommendations include four doses of PCV13 at specific ages (2, 4, 6, and 12-15 months).
• Immunosuppressed individuals require an additional dose of PCV13, followed by PPSV23 after 8 weeks.
• Catch-up vaccination is available for children who have not received all doses.

Haemophilus Influenzae Type B Vaccine

• All infants receive three doses of PRP-OMP (PedvaxHIB) at 2, 4 and 12-15 months, or four other types of hib vaccine at 2, 4, 6, and 12-15 months.
• Vaccines containing hib reduce the number of injections.
• Hib vaccine is generally not needed after age 5.
• Side effects include mild redness, pain, and swelling, low-grade fever.

Poliovirus Vaccine

• Poliovirus spreads primarily via the fecal-oral route.
• Incubation period is 3-35 days.
• Up to 90% of cases are asymptomatic.
• 1-2% are non-paralytic aseptic meningitis.
• Less than 2% are paralytic poliomyelitis.
• Case fatality rate is 2-5% in children and 15-30% in adults.
• A course of four inactivated poliovirus vaccines (IPV) is recommended before school entry.

Influenza Vaccine

• Influenza season sees increased hospitalizations and mortality due to complications like myocardial infarction, bacterial pneumonia, and worsening of other diseases
• Preschool children and infants (<1 year) are most vulnerable
• Children are at increased risk of encephalopathy and death from influenza
• Influenza is highly contagious, transmitted through airborne respiratory drops, primarily.
• Incubation period is 1 to 5 days.

Vaccine Types (Influenza)

• Inactivated influenza vaccine (IIV)
• Live attenuated influenza vaccine (LAIV)

Vaccine Efficacy (Influenza)

• Effectiveness depends on virus matching and recipient immunity.
• IIV has moderate efficacy (40-60%) in young children and good efficacy (over 40-70%) in older children.
• Protection develops within 2 weeks after vaccination.
• Immunity from IIV is limited. Annual vaccination before the flu season is recommended.

Adverse Reactions (Influenza)

• Local reactions to IIV include injection site soreness lasting less than 2 days.
• Systemic reactions, such as fever, malaise, and myalgia, can occur in children not previously exposed to influenza vaccine.
• Rare cases of Guillain-Barré syndrome may occur within 6 weeks of IIV vaccination.

Measles, Mumps, Rubella (MMR) Vaccine

• Measles can cause severe morbidity and even delayed fatal complications like encephalopathy or subacute sclerosing panencephalitis.
• Easily transmitted by people shedding the virus from approximately 4 days prior to rash onset to 4 days after.
• MMR vaccination is crucial to prevent and control outbreaks.

MMR Vaccine Recommendations

• MMR vaccine is usually given routinely at 12–15 months and then again at 4-6 years of age in healthy children.
• Immunocompromised children and those planning to attend college may require special considerations.

Varicella Vaccine

• Varicella-zoster virus (VZV) causes chickenpox.
• High communicability and spread via airborne droplets.
• Severe complications can occur, such as secondary skin infections, pneumonia, and other disorders.
• Chickenpox can reactivate later in life as shingles.
• Varicella vaccine is effective if administered within 3-5 days of exposure.

Recommendations (Varicella)

• The first dose is usually given at 12-15 months, and a second dose 4-6 years old or later.
• Immunocompromised individuals require special precautions to avoid contact with the vaccine-induced rash.

Meningococcal Conjugate Vaccine (MENACYW and MENB)

• Various types of Neisseria meningitidis, some pathogenic and some benign, colonize the throat.
• Transmitted through respiratory droplets.
• Most common in children less than 5 years old, with a further bump in teenagers and young adults.
• Serogroup B accounts for a significant amount of meningococcal disease in young children, while serogroups A and C are common in outbreaks.

Meningococcal Conjugate Vaccine: Vaccine Types

• MenACWY is recommended with booster doses at ages 11-12 and 16.
• Additional doses may be needed for individuals with risk factors, like asplenia, terminal complement deficiencies, or travel to hyperendemic areas.
• Mild local reactions (pain, fatigue, headache) are common.

Rotavirus Vaccine

• Infants receive three doses of RV5 or two doses of RV1 at 6 weeks to 32 weeks.
• Doses are spaced two months apart.
• Side effects include vomiting, diarrhea, irritability, and fever.
• Intussusception is a rare side effect with either vaccine.

Human Papillomavirus (HPV) Vaccine

• HPV is a vaccine against cancers linked to the virus and genital warts.
• Children and adolescents ages 9-26 are eligible to receive it.
• Two or three doses are administered over time.

Adult Vaccines

• Adults above a certain age should receive recommended vaccinations like Tdap, Flu, shingles (Zoster), Pneumococcal (PCV 13, PPSV23), and HPv (9-valent vaccine).

Vaccinations during Pregnancy

• Pregnant women need annual flu vaccinations administered at any stage of pregnancy.
• A Tdap dose is recommended during pregnancy to optimize antibody levels to protect the newborn.