SAN FRANCISCO -- Moderna announced people may need a second booster to increase protection. But is a fourth shot the right approach? ABC7 News reporter Luz Pena from San Francisco spoke to multiple ...

With the Delta variant in play, federal health officials are analyzing the latest numbers to look at the frequency and seriousness of COVID-19 breakthrough infections. Will we need booster shots? And ...

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated. (NEXSTAR) – As COVID cases caused by the ...

Discussions around whether a COVID-19 vaccine booster is necessary can have seemingly conflicting information. “It’s complicated. This is not just a simple equation,” Dr. Michelle Barron, senior ...

As more Americans receive their COVID-19 vaccination daily, many are wondering how long they'll be effective for and whether some people will require booster shots at some point. Dr. Elizabeth Hudson, ...

There have been hundreds of measles cases reported in the U.S. since the beginning of the year. Here's what you need to know ...

WASHINGTON -- People with certain health conditions that make them moderately or severely immunocompromised may get a fourth mRNA COVID-19 shot, according to updated guidelines from the US Centers for ...

LOS ANGELES -- U.S. regulators issued new guidance this week shortening the time that people who received Moderna or Pfizer's COVID-19 vaccine have to wait for a booster, and it's different than the ...

Federal officials have authorized an extra dose of COVID-19 vaccine for certain Americans whose immune systems are compromised, an estimated 7 million people. But hundreds of thousands of others, ...