William Petri, M.D.: How effective is the first shot of the Pfizer or Moderna vaccine?
After a single dose of either vaccine, you have very high levels of protection after your body has time to build immunity, about a week. The scheduled second dose of these vaccines makes them even more effective.
March 20, 2021 · Leave a comment
William Petri, MD: What doctors know about lingering symptoms of coronavirus
Here is a summary of what is known today about recovering from COVID-19, as well as what to expect from lingering effects.
July 6, 2020 · Leave a comment
