Previous vaccines and masks may hold down Covid-19, some researchers say
(WorldNews Health)

As US leaders work to control the spread of coronavirus, researchers across the country -- and globe -- are working to answer the mysteries that remain around infections. One of those mysteries: why the experience can be so different from person to person. One expert says the answer may involve looking at previous vaccines individuals have had. `When we looked in the setting of Covid disease, we found that people who had prior vaccinations with a variety of vaccines -- for pneumococcus, influenza, hepatitis and others -- appeared to have a lower risk of getting Covid...