Types of Vaccination
There are several categories of vaccination, organized by the method of administration, the type of immune response elicited, and the target population, including Inactivated Vaccines, Live Attenuated Vaccines, Subunit Vaccines, Conjugate Vaccines, and mRNA Vaccines.
Main Categories
- Inactivated Vaccines — vaccines containing killed pathogens that cannot replicate, characterized by their inability to cause disease, and exemplified by the Flu Vaccine, which contains inactivated influenza virus and is administered annually to prevent seasonal flu outbreaks.
- Live Attenuated Vaccines — vaccines containing weakened pathogens that can replicate, characterized by their ability to elicit a strong immune response, and exemplified by the Measles, Mumps, and Rubella (MMR) Vaccine, which contains live, attenuated viruses and is administered to children to prevent measles, mumps, and rubella.
- Subunit Vaccines — vaccines containing only specific components of a pathogen, characterized by their reduced risk of adverse reactions, and exemplified by the Hepatitis B Vaccine, which contains a surface antigen from the hepatitis B virus and is administered to prevent hepatitis B infection.
- Conjugate Vaccines — vaccines containing a weakened pathogen linked to a carrier protein, characterized by their ability to enhance immune response, and exemplified by the Pneumococcal Conjugate Vaccine, which contains weakened pneumococcal bacteria linked to a carrier protein and is administered to prevent pneumococcal disease.
- mRNA Vaccines — vaccines containing genetic material from a pathogen, characterized by their ability to elicit a specific immune response, and exemplified by the Pfizer-BioNTech COVID-19 Vaccine, which contains mRNA from the SARS-CoV-2 virus and is administered to prevent COVID-19.
Comparison Table
| Vaccine Type | Cost | Scale | Speed | Risk |
|---|---|---|---|---|
| Inactivated Vaccines | Moderate (~$10-50 per dose) (CDC) | Large (millions of doses) | Slow (months to develop) | Low |
| Live Attenuated Vaccines | Low (~$5-20 per dose) (WHO) | Medium (thousands to millions of doses) | Moderate (weeks to months to develop) | Moderate |
| Subunit Vaccines | High (~$50-100 per dose) (GSK) | Small (thousands of doses) | Slow (months to years to develop) | Low |
| Conjugate Vaccines | Moderate (~$20-50 per dose) (Pfizer) | Medium (thousands to millions of doses) | Moderate (weeks to months to develop) | Moderate |
| mRNA Vaccines | High (~$100-200 per dose) (Moderna) | Small (thousands of doses) | Fast (weeks to develop) | Low |
How They Relate
The categories of vaccination often overlap, with some vaccines combining elements of multiple categories, such as Conjugate Vaccines, which use a combination of weakened pathogens and carrier proteins. Inactivated Vaccines and Live Attenuated Vaccines are commonly confused due to their similar methods of administration, but they differ in their ability to replicate and elicit an immune response. Subunit Vaccines and mRNA Vaccines are often compared due to their focus on specific components of a pathogen, but they differ in their use of genetic material versus protein components. Pfizer-BioNTech COVID-19 Vaccine and Moderna COVID-19 Vaccine are examples of mRNA Vaccines that have been developed and administered in response to the COVID-19 pandemic, demonstrating the ability of mRNA Vaccines to be developed quickly and elicit a specific immune response.