Should I get a COVID shot? CDC says most should wait for September

Update: The new COVID vaccines from Moderna and Pfizer have been greenlighted by the FDA and CDC and will begin rolling out Sept. 13. Read the latest here. Our earlier story is below.

Despite signs of a weekslong increase in COVID-19 hospitalizations nationwide, the Centers for Disease Control and Prevention are now warning most vaccinated Americans against seeking out getting another booster this month.

New vaccines redesigned to broaden immunity for currently circulating variants are on the way next month, officials say. Getting a shot now could mean you won't be eligible for one of those updated boosters after they are rolled out in mid-September, at a time when COVID-19 rates are projected to be even higher. 

That means that, except for still unvaccinated Americans or those who are older or at higher risk of severe disease, it might now be better to wait for the updated shots.

"If you do get the current COVID 19 vaccine now, or in early September, it could delay your ability to get this updated vaccine that's coming out in the middle of September. So again, talk to your doctor or nurse practitioner," CDC Director Dr. Mandy Cohen said Friday.

Why getting a COVID shot now could delay your next one

Guidance from the CDC and authorizations from the Food and Drug Administration already restrict most people from getting the current COVID-19 boosters less than two months after a person's last shot for the same virus. 

That stems from data earlier in the pandemic which suggests spacing out shots can trigger stronger immune responses against the virus, as well as decrease the risk of rare but serious side effects for some groups. 

It is possible this kind of interval could apply to the new COVID-19 vaccines for this fall, depending in part on what the CDC's outside advisers recommend at their upcoming meeting to weigh the updated shots in mid-September.

"Getting a COVID shot now could delay getting the updated one if the data demonstrates to CDC and ACIP that an interval between shots is warranted," CDC spokesperson Jason McDonald told CBS News in an email.

Doctors are generally not required by law to follow the advisory panel's recommendations when giving shots. They can also give fully approved vaccines "off-label" outside the FDA's indication.

However, getting a shot outside what the CDC recommends and FDA approves could mean you'll have to pay out of pocket for the vaccinations, which are otherwise required to be covered by insurance for virtually all insured Americans. Vaccinators may also be wary of opening themselves up to lawsuits by giving the shots against those approvals.

When is the best time to get the new fall COVID shots?

Health authorities say they plan to urge Americans to start getting the updated COVID-19 shots next month, alongside immunizations for seasonal influenza and – to protect some older adults and newborns – RSV, or respiratory syncytial virus. 

The new COVID-19 shots, which were redesigned to broaden immunity for the XBB.1.5 variant that drove a wave earlier this year, are expected to be available after a meeting of the CDC's vaccine advisers scheduled for Sept. 12. 

XBB.1.5 is closely related to current strains that are dominant in the U.S. like EG.5.

That CDC meeting date was picked to come "as close as possible" after the FDA's approval or authorizations of the new vaccines from Moderna, Novavax and Pfizer, officials said.

"So to the extent that there is more data that would be coming, and that clinicians are looking to CDC for what the ultimate recommendations are for clinical practice, there's as short of a delay as possible," a CDC official told reporters.

It is possible the meeting could also yield more detailed recommendations on when exactly is best to get the updated vaccines this coming season, akin to what is offered to doctors about timing shots for flu or RSV. 

Vaccines reach the highest effectiveness in the most recent weeks after they are given before they begin to wane, data previously presented to the panel suggests. Some at-risk Americans may also be recommended to get more than one COVID-19 booster this fall, officials have said. 

But beyond the ongoing increase of COVID-19 hospitalizations driven by current variants, other factors – like the emergence of a new highly-mutated variant called BA.2.86, which could drive a renewed wave later this fall and winter – might complicate recommendations.

Experts worry if BA.2.86 becomes more widespread, the upcoming shots and immunity from prior infections might be a poor match to the variants circulating, though more data is needed on the strain's impact. The CDC says it assesses the updated vaccines will still "be effective at reducing severe disease and hospitalization."

For now, authorities say they are not planning to roll out yet another update to the vaccines until next year. That will change only if the strain or other variants prove to be markedly more dangerous.