The Centers for Disease Control and Prevention expects updated Covid vaccines from Pfizer, Moderna and Novavax to be available to the public in mid-September, an agency official told reporters Thursday. 

That amounts to the most specific timeline to date. Federal officials have said the new shots could arrive around September. CDC Director Mandy Cohen had previously provided a later timeline, telling NPR that the vaccines could be available by the “early October time frame.”

Those shots still need approvals from the Food and Drug Administration and the CDC, which will set eligibility guidelines for the jabs. An independent panel of advisors to the CDC is meeting on Sept. 12 to vote on a recommendation for those guidelines. 

Officials from the CDC and FDA said the agencies will encourage Americans to receive an updated Covid shot and other key vaccines ahead of the fall, when respiratory viruses typically begin to spread more widely. That includes the annual flu shot and recently approved jabs that protect older adults and infants from respiratory syncytial virus.

“Our goal, our imperative, our task is to make sure we’re using those tools,” the CDC official said. “Vaccination is going to continue to be key this year because immunity wanes and because the Covid-19 virus continues to change.”

The arrival of updated vaccines offers some reassurance to Americans as the U.S. sees a slight uptick in Covid cases and hospitalizations. But those metrics remain below the summer peak that strained hospitals last year, the CDC official noted. 

The current surge appears to be fueled by newer strains of the virus like EG.5, or Eris, an omicron subvariant that accounted for 17.3% of all cases as of last week, according to the CDC. 

Pfizer, Moderna and Novavax designed their updated vaccines to target the omicron subvariant XBB.1.5, which is slowly declining in prevalence nationwide. But initial trial data from all three drugmakers suggest the new shots will still protect against EG.5. 

“One of the manufacturers have already made it clear that when testing their vaccine against the EG.5 that it looks like the neutralization is robust,” an FDA official told reporters Thursday. 

But it’s unclear how well the new shots will protect against another new omicron strain of the virus called BA.2.86, which has been identified in a very small number of cases in the U.S., U.K., Denmark and Israel.

“I think it’s too early to know for sure about BA.2.86 in terms of exact data,” the FDA official said, adding that more information will be available in the coming weeks. 

However, the official noted that the new vaccines will likely protect against any severe outcomes from catching the Covid virus.

Last week, the World Health Organization and the CDC said they are tracking BA.2.86 because it has 36 mutations that distinguish it from XBB.1.5. So far, there is no evidence that BA.2.86 spreads faster or causes more serious infections than previous versions.