Vaccine Creation and Development

Vaccine Creation and Development

• The first step in creating a vaccine is identifying the virus or bacterium that causes the disease.
• Vaccines can be made with weakened or deactivated pathogens, but this is not always an option.
• Pathogen antigens should be identified when using weakened or deactivated pathogens isn't an option.
• Antigens are unique protein or glycoprotein markers and can form the basis of a new vaccine.
• Some pathogens' antigens remain constant, but others, such as the flu virus, mutate and need annual re-analysis.
• The vaccine platform determines how the identified pathogen or antigens will be used to build a vaccine.
• Subunit vaccines, which only use part of the pathogen, and newer technologies like viral vector or nucleic acid-based vaccines are examples of vaccine platforms.
• The method of vaccine administration has an impact on the immune response.
• Injection, oral administration, and nasal administration are examples of administration methods.
• The designed vaccine must be tested, first in cell cultures and then in animal models.
• Vaccinated animals are deliberately exposed to the target disease in challenge studies to see if the vaccine protects them.
• If the disease is not too serious or effective treatments are available, human challenge studies may be conducted.
• GMP certification is required to demonstrate that the vaccine can be manufactured to a high standard and at scale.

Human Trials and Approval

• Human trials have three phases, all of which must be completed.
• Phase 1 involves administering the vaccine to a small group of healthy people to test for adverse reactions (safety trial).
• Phase 2 involves administering the vaccine to hundreds of people to determine the dose required to trigger an adequate immune response.
• Phase 3 involves trialling the vaccine in thousands of people to determine its effectiveness, which is often the slowest step.
• Researchers monitor how many participants become infected to determine the vaccine's effectiveness.
• Gathering enough data to be certain of the vaccine's effectiveness can take decades.
• Mass production of a vaccine to a high standard can be difficult once it is licensed.
• Getting the vaccine to where it is needed is difficult.
• Phase IV monitoring entails tracking rare adverse reactions that the vaccine may cause even after previous trials have been completed.

Speeding up Vaccine Production

• The vaccine production process can be expedited, but steps are never skipped.
• Reducing the time spent waiting for paperwork.
• Running different trial phases at the same time are ways to speed up the process.
• Working more efficiently could result in the production of a protective vaccine in as little as twelve to eighteen months.
• Advances in biotechnology have the potential to speed up production pipelines.

Newer Vaccine Platforms

• Nucleic acid vaccines deliver genetic templates for antigens rather than using pathogens or antigens directly.
• DNA or RNA templates can be delivered directly or in lipid nanoparticles to enter cells and improve stability after injection.
• Lipid nanoparticles can also act as adjuvants, which are molecular triggers that kick start the immune response.
• Inside the body, DNA or RNA templates instruct cells to produce antigens, which activate the immune response.
• RNA and DNA are easier and faster to produce in the lab than antigens.
• Nucleic acid vaccines are potentially safer than vaccines containing whole pathogens and could be used by people with weakened immune systems, but they are still experimental.
• Viral vector vaccines insert an incomplete segment of genetic material from a pathogen into a harmless virus.
• The harmless virus transports the genetic material, delivering it to the right location in the body.
• The genetic material is then translated into proteins, which trigger the immune system.
• The viral vector may be self-replicating, increasing the amount of vaccine in the body.
• Viral vector vaccines are quick to produce, and safe vectors have already been identified.
• Because the genetic material inserted is incomplete, it cannot replicate and cause disease, making them very safe.

Future of Vaccines

• Effective vaccines have the potential to save millions of lives, but they must be proven safe and effective, which can be a slow and methodical process.
• Researchers hope to develop vaccines against non-infectious diseases such as cancers based on chemical markers known as tumour neoantigens.