COVID vaccines 101


Alessandra Borges


There are three main types of COVID-19 vaccines: The mRNA vaccine, the Vector vaccine and the Protein subunit vaccine and while they work in different ways, they all offer protection from the virus. 

The mRNA vaccine, instructs cells to make a non-threatening piece of a protein called “spike protein” found on the exterior of the virus that causes COVID-19. After cells make the protein it moves to the surface of the cell. The immune system then recognizes that this piece of protein does not belong there and begins to produce antibodies. Both Pfizer and Moderna’s vaccines are mRNA vaccines, requiring 2 doses, their efficacy rate is about 95% and they are being widely distributed throughout the country. According to the Florida Department of Health, as of April 11, 11% of Florida residents have been vaccinated with either a mRNA vaccine (Pfizer or Moderna), or a Vector vaccine (Johnson & Johnson), which I will talk about now.

Viral vector-based vaccines differ from conventional vaccines in that they don’t contain antigens, but use the body’s own cells to produce them. This is done by injecting a modified, non-live virus (the vector) to deliver genetic code for antigen. By infecting cells and instructing them to make large amounts of antigen, an immune response is triggered. Johnson & Johnson created a Vector vaccine which requires only one dose and has an efficacy of 90%. While the distributions of the vaccine began in March, it was temporarily halted because of concerns over blood clots, and was evaluated. As of April 24, the vaccine is back in circulation and is considered to be safe for use now.  The AstraZeneca vaccine, also a vector vaccine, has an efficacy rate of 76% with the first dose, and 82% with the second. 

In the case of Protein Subunit vaccines, rather than injecting the entire neutralized virus into the body, it injects only fragments of what causes COVID-19, like the spike proteins that are part of the virus.

The Pfizer,Moderna and Johnson & Johnson vaccines are all available in Florida so which one should you get? Dr. Fauci advises, “I would recommend, get the first one you could get.”