Data from the Novavax clinical trial also show that Novavax is more than 90% effective at protecting against symptomatic COVID-19, and 100% effective against severe illness and death. Common side effects include soreness at the injection site, fatigue, muscle pain, and headaches. 

In terms of serious adverse reactions to Novavax, data show there were six cases of myocarditis from a clinical trial of about 30,000 people, primarily among young men. The cases of myocarditis in the clinical trial were treatable, and all six individuals recovered well. The risk of developing myocarditis from COVID-19 remains higher than the risk of developing it from a COVID-19 vaccine, including Novavax.

Updated June 29, 2022