It seems possible, though how often it happens isn’t known. Even if people can get reinfected, the World Health Organization says it likely wouldn’t happen regularly. Health experts generally believe people who had COVID-19 will have some immunity against a repeat infection. But they don’t know how much protection, or how long it would last. This is important because if immunity wears off, it could pose a challenge for vaccines. Some experts say booster shots may be needed. It’s also unclear whether reinfected people would be able to spread the virus to others.