Pfizer is now leading the coronavirus vaccine race: The company announced Monday that people who received its two shots during the company’s final stage of clinical trials were less likely to develop COVID-19. The results indicate the vaccine is more than 90% effective in preventing the disease.
Like the other leading vaccine candidates in the US, Pfizer’s shot does not inject the actual virus, SARS-CoV-2, into the body, contrary to popular myth. Instead, the vaccines all rely on a harmless segment of the virus to spur the production of antibodies.
But to stimulate that immune response, different vaccines rely on different technologies. Pfizer’s candidate is an mRNA vaccine, an unproven technology that uses a snippet of the coronavirus’ genome to encourage antibody production. Moderna’s uses the same approach, though no mRNA vaccine has