coronavirus immunity

An analysis of blood from people who had received the Johnson & Johnson COVID-19 vaccine found a lower level of neutralizing antibodies against viral variants but a strong response involving T cells.

First, can someone who has been vaccinated still spread the disease? Second, will the vaccine remain effective as the virus itself evolves? And third, how long will the vaccine's protection last?

There's a lot that scientists don't know about how viral infections can interact. But researchers are eager to figure out how coronavirus infections might affect flu infections and vice versa.

A vaccine against the coronavirus needs to keep people from getting very sick and dying. But preventing the spread of the disease is also important, and vaccines delivered by nasal spray may do that.