The U.S. death toll from COVID-19 topped 600,000 on Tuesday, even as the vaccination drive has drastically brought down daily cases and fatalities and allowed the country to emerge from the gloom and look forward to summer.
A small study offers the first hint that an extra dose of COVID-19 vaccines just might give some organ transplant recipients a needed boost in protection.
Vaccine maker Novavax said Monday its COVID-19 shot was highly effective against the disease and also protected against variants in a large study in the U.S. and Mexico, potentially offering the world yet another weapon against the virus at a time when developing countries are desperate for doses.