Early data suggest several of the coronavirus vaccines may cause people to feel crummy for a few days. And then they'll need a second dose.
Liz Szabo, JoNel Aleccia
Kaiser Health News
Pfizer is expected to seek federal permission to release its Covid-19 vaccine by the end of November, a move that holds promise for quelling the pandemic but also sets up a tight time frame to make sure consumers understand what it will mean to get the shots.
The vaccine, and likely most others, will require two doses to work, injections that must be given weeks apart, company protocols show. Scientists anticipate that the shots will cause enervating flu-like side effects — including sore arms, muscle aches and fever — that could last days and temporarily sideline some people from work or school. And even if a vaccine proves 90 percent effective, the rate Pfizer touted for its product, 1 in 10 recipients would still be vulnerable. That means, at least in the short term, as population-level immunity grows, people can't stop social distancing and throw away their masks. Read more >>