Types of Vaccines
Scientists around the world are working on the development and distribution of vaccines for COVID-19. It is not known if we will need a COVID-19 vaccine every year. Many COVID-19 vaccines currently in development are two-dose vaccines, including the two recently approved vaccines – one from Pfizer and one from Moderna. Both offer minimal protection after the first dose and fuller immunity within seven days of the second dose. What is not known is if we will need a COVID-19 vaccine every year.
mRNA Vaccine by Pfizer
On December 11, 2020, the Food and Drug Administration (FDA) announced an emergency use authorization (EUA) for the Phizer-BioNTech COVID-19 vaccine. This vaccine is reported to be approximately 95% effective at preventing COVID-19. The two-dose vaccine claims protection is achieved 7 days after the second dose, which is delivered 21 days after the first dose, with no serious safety concerns observed.
Learn more from our FAQs and the Pfizer-BioNTech FactSheet for recipients and caregivers
mRNA Vaccine by Moderna and the U.S. Government
Having completed Phase 3 clinical trials, this vaccine was reviewed and granted EUA status on December 18. Early results indicate it is safe and produces high levels of antibodies to the SARS-CoV-2 virus. This vaccine is also reported to be approximately 95% effective.
Common Types of Vaccines
- Inactivated Vaccines use the specific virus or bacteria (pathogen) after it’s been killed with heat or chemicals. The dead pathogen is introduced into the body but can still teach the body’s immune system how to fight the live versions of the pathogen in the future. In the United States, the injected polio is an example of an inactivated vaccine.
- Live, Attenuated Vaccines use a weakened (attenuated) version of the living virus or bacteria. These vaccines are close to a natural infection so they teach the immune system how to fight the full strength pathogen. Live, attenuated vaccines do not cause serious disease in people with healthy immune systems. Chickenpox, and the measles, mumps and rubella vaccines are examples of this type of vaccine.
- DNA/RNA or Genetic Vaccines use a small part of the pathogen’s genetic information to cause an immune response without causing disease or harm.
This information has been reviewed and approved by Stephen K. Frankel, MD, FCCM, FCCP (December 2020).