Advisers to the Centers for Disease Control and Prevention on Tuesday endorsed the new shots for everyone 6 months of age and older. The agency's director is expected to sign off on the panel's recommendation. The vaccines could be available this week.

"Since entering office, my Administration has made historic progress in our ability to manage COVID-19 so that it no longer meaningfully disrupts our lives. Today marks another important milestone," President Joe Biden said in a statement. "Vaccination against COVID-19 remains the most important protection in avoiding hospitalization, long-term health complications, and death. I encourage all Americans to stay up-to-date on their vaccines."

The severity of the COVID-19 pandemic has faded, but there are still hundreds of hospitalizations and hundreds of deaths in the U.S. each week. Hospitalizations have been increasing since late summer, though the latest data indicate infections may be starting to level off, particularly in the South.

Still, experts worry that immunity from previous vaccinations and infections is fading in many people, and a new shot would save many lives.

Doctors hope enough people get vaccinated to help avert another “tripledemic” like last year when hospitals were overwhelmed with an early flu season, an onslaught of RSV, or respiratory syncytial virus, and yet another winter coronavirus surge.

Just like earlier vaccinations, the fall round is cleared for adults and children as young as age 6 months. FDA said starting at age 5, most people can get a single dose even if they’ve never had a prior COVID-19 shot. Younger children might need additional doses depending on their history of COVID-19 infections and vaccinations.

The newest shots target an omicron variant named XBB.1.5. That specific strain is no longer dominant but it’s close enough to coronavirus strains causing most COVID-19 illnesses today that FDA determined it would offer good cross-protection.

The updated vaccines will replace combination vaccines that mixed protection against the original coronavirus strain and even older omicron variants. Like earlier versions, they're expected to be most protective against severe illness, hospitalization and death, rather than mild infection.

Health officials are optimistic, barring a new mutant. As expected, XBB.1.5 has faded away in the months it took to tweak the vaccine. Today, there is a soup of different coronavirus variants causing illness and the most common ones are fairly close relatives. Recent lab testing from vaccine makers and other research groups suggest the updated shots will offer crossover protection.

“Vaccination remains critical to public health and continued protection against serious consequences of COVID-19, including hospitalization and death,” said Dr. Peter Marks, the director of the FDA’s Center for Biologics Evaluation and Research, in a statement. “The public can be assured that these updated vaccines have met the agency’s rigorous scientific standards for safety, effectiveness, and manufacturing quality. We very much encourage those who are eligible to consider getting vaccinated.”

Earlier vaccinations or infections have continued to help prevent severe disease and death but protection wanes over time, especially against milder infections as the virus continually evolves. The FDA did allow seniors and others at high risk to get an extra booster dose last spring. But most Americans haven’t had a vaccination in about a year; only about 20% of adults ever received the combo version.

The CDC decides how best to use vaccines and makes recommendations for U.S. doctors and the general public. The agency's panel of outside exerts recommended the updated COVID-19 shots by a vote of 13-1. The no vote came from a panel member who had argued that the new shots should initially be recommended only for older people and others at greatest risk of severe illness. But other panel members said all ages could — and should — benefit.

“We need to make vaccination recommendations as clear as possible,” said one panel member, Dr. Camille Kotton, an infectious diseases doctor at Massachusetts General Hospital.

The new vaccine will be available at pharmacies, health centers and some doctor offices. Locations will be listed on the government's vaccines.gov website. The list price of a dose of each shot is $120 to $130, according to the manufacturers. But federal officials said the new COVID-19 shots still will be free to most Americans through private insurance, Medicare or Medicaid. For the uninsured or underinsured, the CDC is working with health departments, clinics and certain pharmacies to temporarily provide free shots.

On Tuesday, a Pfizer official said his company expected to have doses available at some U.S. locations as early as Wednesday.