In January 2021, [Joe] Gallo contracted COVID. … Gallo told the Nationals he had “natural immunity” from the virus. … “His prior infection does not give him durable immunity,” said UC Irvine epidemiologist Andrew Noymer, [associate professor of public health]. The vaccine might not do that either. Gallo wondered how we can proclaim the vaccine is effective when vaccinated people keep getting infected. “I’m sorry to say he is right on that point,” Noymer said, “at least partly.” … For now, Noymer said, the COVID vaccine resembles the flu shot: It can reduce your risk of infection, and it can reduce the risk of severe illness if you do get infected, but it cannot eliminate the risks.