COVID is rising. New vaccines may not be ready until mid-September.

Coronavirus infections are climbing again, marking another summer wave as children go back to school.

But this uptick arrives with an added layer of uncertainty because it’s unclear when and which Americans can receive updated vaccines this fall.

Daniel R. Kuritzkes, chief of the division of infectious diseases at Brigham and Women’s Hospital in Boston, said the current rise looks similar to seasonal bumps in previous years and is not driving a surge in severe illness.

This is the new rhythm of COVID waves. Many people are getting sick — some feeling lousy — especially after returning from vacation and conferences. Most probably won’t even know it’s COVID because the symptoms can be indistinguishable from a cold or other respiratory bug. Yet hospitals are no longer flooded with patients because immune systems are much better trained to fight the virus five years after it arrived.

But Kuritzkes and other medical and public health experts worry that delays and confusion surrounding the vaccines will limit access for those who need them the most: Adults ages 65 and older and people who have chronic conditions, weakened immune systems or are pregnant.

The federal committee that would recommend the updated coronavirus vaccine is not expected to meet until at least mid-September, according to industry employees and Centers for Disease Control and Prevention officials who spoke on the condition of anonymity to share sensitive information. By that point, the summer COVID wave could be over, but Americans could still get a boost of immunity ahead of an expected winter wave.

Here’s what to know about the latest with COVID and how to protect yourself:

Viral levels in wastewater started rising in late June and are considered high in the West, South and Midwest and headed that direction in the Northeast, according to Marlene Wolfe, principal investigator and co-program director of WastewaterSCAN, a private initiative that tracks municipal sewage data.

The levels of virus are roughly one-third of the levels recorded a year ago, when the country was experiencing an unusually large summer COVID wave.

Emergency room data suggests infections are disproportionately affecting children.

As of Aug. 7, coronavirus diagnoses accounted for 2.18 percent of emergency room visits among children up to age 11, the largest jump of any age group. Still, some experts caution that numbers are still very small.

Aaron Milstone, a pediatric infectious-disease specialist at Johns Hopkins University School of Medicine, said most children now have some level of hybrid immunity from prior infection and vaccination. But vaccines still play a key role in giving a child’s body a robust immune response, he said.

Coronavirus is always evolving to become more transmissible or adept at overcoming the frontline immune defenses that stop infections.

The current predominant variant is XFG, according to CDC wastewater tracking. XFG is an offshoot of the JN.1 subvariant of omicron that became dominant in the winter of 2023-2024.

The Food and Drug Administration has advised vaccine manufacturers to update their formulas to target the JN.1 lineage, specifically using the LP.8.1 strain that was dominant in the spring and is closely related to XFG.

The latest variants do not appear to cause worse symptoms or have significant differences compared with its predecessors, according to Scott Roberts, an assistant professor of infectious diseases at Yale School of Medicine.

For the coming fall season, the FDA has not yet approved an updated coronavirus vaccine. In recent years, the agency has typically signed off on an updated version by late August or early September in order for pharmacies and doctors’ offices to place orders.

Once the FDA gives the greenlight, the CDC’s Advisory Committee on Immunization Practices decides who should get the shots. Most insurers must pay for ACIP-recommended vaccines. Most of the newly appointed members of that committee have been critical of U.S. coronavirus vaccine policy.

It’s unclear whether Americans who are not considered high risk could still pay out-of-pocket to get a coronavirus vaccine off-label. That depends on the willingness of — and legal restrictions on — health care providers who would administer shots.

Most Americans have at least one condition that puts them at higher risk of severe illness from COVID. Physical inactivity, asthma, obesity, smoking and mood disorders are among the widespread risk factors highlighted under the new FDA framework for coronavirus vaccine approval.

AHIP, the major insurance lobby, has said its members are committed to maintaining coverage of vaccines for the upcoming respiratory virus season.

The FDA may not sign off on Pfizer’s updated coronavirus vaccine for children between the ages of six months and 4, the company said in a statement, adding the change has nothing to do with the safety and efficacy of the shot. However, the agency recently granted full approval to Moderna’s shot for young kids at risk of severe disease.

Public health experts say the best way to protect yourself from COVID is to stay up-to-date on vaccines.

The 2024-2025 vaccine formula is still available. But it might be harder to find because some doctors and pharmacies may have decided not to restock their supplies while they wait for a new version to arrive.

The CDC recommends two doses of the vaccine for people who are 65 and older or are immunocompromised.

Jessica Justman, an infectious disease specialist at Columbia University, said if someone in those groups had not yet received their second dose, they should go ahead and get it now, especially if they anticipate increased exposure such as attending a large indoor gathering.

The primary purpose of vaccination is to reduce the risk of severe disease, hospitalization and death. For those wanting to avoid infections completely, experts advise wearing surgical or KN95/N95 masks, avoiding crowded indoor settings and ventilating rooms.