Because COVID-19 is a relatively new virus, researchers still aren’t sure exactly how long vaccines and prior infections provide protection.

COVID-19 may transition from pandemic to endemic, but when and how will we get there? One expert cautions against "declaring that we're done."

Calculating your risk of death or hospitalization if you are infected with the coronavirus requires good data – notably, the total number of infections in the US. Unfortunately, that data is fuzzy.

New details about the structure of the HIV virus may help in the design and development of a vaccine that can protect against AIDS.

Identifying "fence-sitters," adults ambivalent about vaccines, and using community members to relay reliable information could ease vaccine hesitancy.

Whether about a comet hitting the Earth or a virus infecting the world, fear-based messages often do not succeed at changing people’s behaviors.

People who exercise for 90 minutes immediately after receiving a flu or COVID-19 vaccine may get an extra immunity boost, researchers report.

A new survey shows young moms worried more about money than avoiding COVID-19 and were more hesitant about having their kids get the vaccine.