The COVID-19 virus is still circulating even as life has essentially returned to normal. That’s why those most vulnerable to severe illness must stay up to date on their vaccinations.

New guidance from federal health officials has cleared a second “bivalent” COVID-19 booster shot available for those 65 and older and those with health conditions that weaken their immune systems. “Bivalent” just means that the shot protects against new strains of the COVID-19 virus.

This updated vaccine debuted last fall for general use, meaning many people (though not enough!) have already had a bivalent booster in addition to their primary series of shots. The recent move by the Food and Drug Administration and the Centers for Disease Control and Prevention makes a second bivalent booster more narrowly available, limiting use to those whose age or health conditions elevate their risk of hospitalization or death.

If you or your loved ones fall into these two key groups, getting a second bivalent booster is prudent.

There’s compelling new evidence to get this second shot if you’re eligible. An analysis published April 12 in the New England Journal of Medicine concluded that the bivalent booster bolstered vaccine recipients’ protection against severe sickness or death. However, overall protection provided by the shot diminished in the months afterward – a reality that should spur those who qualify for a second booster to act.

In addition to age and health status, the new guidance includes time elapsed since the first bivalent booster: At least four months for those 65 and up and at least two months for those with weakened immune systems.

Nationally, about 94,000 new cases of COVID-19 are reported each week. And although that number is among the lowest tallies since the pandemic’s beginning, it’s still too many people getting sick with a potentially fatal virus. The most recent national weekly death toll stands at 1,160. COVID also has repeatedly shown that it can return with a vengeance after a lull.

So why didn’t federal health officials OK a second booster for younger people without serious health conditions?

A statement from the FDA suggests that authorities are trying to simplify COVID vaccine guidance. And that “most of the U.S. population 5 years of age and older has antibodies to SARS-CoV-2, the virus that causes COVID-19, either from vaccination or infection that can serve as a foundation for the protection provided by the bivalent vaccines.”

Essentially, protection from one bivalent booster should be sufficient for now in those under 65 with normal immune systems. But, as always, stay tuned for updates. This is still a new virus, and guidance is evolving as vaccines are updated and data gathered about their durability.

Plenty of people also still need to get the first bivalent booster. According to the CDC, just 16.7% of the U.S. population has had one. Among those 65 and older, it’s an alarming 42.4%. 

There’s plenty of room for improvement. And there’s good news as well for those who have never gotten a COVID-19 vaccine: Most people ages 6 and up don’t need to complete the multiple-shot primary vaccination series. They can just get a single dose of the bivalent vaccine, the CDC says.

It’s not time to let down our collective guard. Up-to-date vaccinations are vital to protect those most vulnerable to a still-circulating and still-dangerous virus.