How safe is someone after the first dose?
As the COVID-19 vaccines reach more people across the country, some people have asked: Could we delay the second dose of the Pfizer and Moderna vaccines to allow more people to be vaccinated more quickly? And, how safe am I after my first dose? As an immunologist, I hear this question frequently. The answer is that a single dose is very effective – but I would add that you should still get both doses. The issue is important, however, not only for your personal health but also for the country’s health as leaders figure out how to ensure there’s enough vaccine for everyone who wants one. A recent study in Israel showed that a single dose of the Pfizer COVID-19 vaccine is highly effective, up to 85%. The Sheba Medical Center reported its experience with vaccinating its nearly 10,000 staff members with the Pfizer COVID-19 vaccine. Vaccination there started Dec.19,2020, which coincided with the third wave of COVID-19 in Israel. The researchers looked to see the rate of reduction in SARS-CoV-2 infection and COVID-19 disease after vaccination.
