What side effects are expected with the Moderna vaccine?

It is important to note that the vaccine cannot give anyone the virus. Sore arm, injection site soreness and/or redness, some experience systemic side effects/immune response like muscle aches, fatigue, low grade fever, some reported a headache. These symptoms are likely to last 1-2 days, no more than one week and much less severe than actually getting the virus itself. In the Moderna clinical trial, systemic reactions were reported by the majority of vaccine recipients was higher in the younger age group (18-64 yo) than the older age group (81.9% vs 71.9% after dose 2). Within each age group, the frequency and severity of systemic reactions was higher after dose 2 than dose 1. For both age groups, fatigue, headache and myalgia were the most common.

Not everyone will experience significant side effects. This does NOT mean the vaccine isn’t working.

The CDC is actively collecting info about side effects – sign up with V-safe after getting the vaccine and get texts that ask several questions about how you feel. This is part of the ongoing active monitoring for safety.


Reviewed (No Change): February 9, 2021