Dr. Marc Siegel: I had measles and don't need a vaccine to protect me. What if I've had COVID?

Similarly, no one should wish for COVID-19, but if you have it, it is clear that your immunity lasts for at least several months if not longer.

I also had chicken pox, which means I don’t need a varicella vaccine, though I am at greater risk for getting a severe case of shingles (recurrence of the virus that causes chicken pox which is harbored in my nerves) than if I had received the vaccine.  The point is that natural immunity after infection isn’t perfect, but it is important. Similarly, no one should wish for COVID-19, but if you have it, it is clear that your immunity lasts for at least several months if not longer. In fact, a new study from Cleveland Clinic looking at over 50,000 workers there beginning in December found that the group that received the vaccine did no better at fending off COVID than the group that had already had it (5 percent of employees). (Both groups didn’t get sick with COVID).