There are several types of vaccines, each designed to elicit a robust immune response:
- Live-attenuated vaccines: Contain weakened forms of the pathogen, such as the measles, mumps, and rubella (MMR) vaccine. - Inactivated vaccines: Contain killed pathogens, such as the polio vaccine. - Subunit, recombinant, or conjugate vaccines: Contain specific pieces of the pathogen, such as the hepatitis B vaccine. - mRNA vaccines: Use messenger RNA to instruct cells to produce a protein that triggers an immune response, such as the Pfizer-BioNTech and Moderna COVID-19 vaccines. - Vector vaccines: Use a different virus to deliver genetic material from the pathogen, such as the Johnson & Johnson COVID-19 vaccine.
