Sam Fazeli, Columnist

Covid-19 Reinfections Are Real. Should You Be Worried?

An effective vaccine may keep Covid-19 at bay even if the virus lingers in one form or another. But there are unknowns.

A wave of fresh outbreaks is causing a spike in new Covid-19 cases worldwide. That’s before any reinfections.

Photographer: Pau Barrena/AFP via Getty Images
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We all suffer multiple bouts of the common cold throughout our lives and never think twice about it. We live with recurring influenza seasons despite a vaccine. But what about Covid-19?

Repeat occurrences of cold and flu happen because our immune systems seem to “forget” the previous infection. Sometimes, a case isn’t serious enough for the body to develop an immune reaction and create a “memory” to help fight it the next time. In other cases, the virus has changed enough such that the immune system doesn’t recognize it and has to mount a brand new reaction. This tends to happen with the flu because it mutates a lot, and is why vaccines targeting a specific flu strain become less effective as new ones arise.