This spike protein, though harmless, is capable of triggering our immune system to produce antibodies that offer protection against future infection.
Novavax's vaccine is a protein adjuvant that contains the spike protein of the coronavirus itself, but formulated as a nanoparticle that cannot cause disease. The injected vaccine then stimulates the immune system to produce antibodies and T-cell immune responses.
The Vaccine Doses: The vaccines from each of the three companies require two doses. Each dose consists of 30 mcg for Pfizer and 100 mcg for Moderna, while for Novavax, each vaccine dose consists of 5 mcg of NVX-CoV2371 and 50 mcg of Matrix-M1 adjuvant that are co-formulated.
The interval between the two doses — the priming and booster dose — is 21 days each for Pfizer and Novavax and 28 days for Moderna.
The Target Population: The original late-stage trial of Pfizer-BioNTech evaluated the vaccine in participants ages 16 years and older. The trial enrolled 43,448 participants.
Moderna's Phase 3 COVE study enrolled 30,000 participants ages 18 years and up.
Since then, these two companies have obtained authorizations for their respective vaccines to be used in adolescents.
Both
companies have also initiated studies in the pediatric population.
Novavax's study enrolled 29,960 participants 18 years of age and older across 119 sites in the U.S. and Mexico. The placebo-controlled portion of PREVENT-19 continues in adolescents from 12 to less than 18 years of age and recently completed enrollment with 2,248 participants.