BA.5 variant will keep Massachusetts at a COVID-19 plateau through the summer, experts predict

As the BA.5 variant of the coronavirus spreads rapidly around the country, it carries a clear message that no one wants to hear: COVID-19 is going to be with us for quite a while longer, and pretending otherwise will only strengthen the virus’s hand.

Experts disagree on whether BA.5 is more contagious or troublesome than previous subvariants of Omicron. But they’re unified in predicting there will be no summer lull: the virus likely will continue to simmer in the population, leading to more infections and hospitalizations, although probably not a dramatic surge in severe illness.

“There is this kind of persistent creeping wave of infection that we’re in at the moment,” said Dr. Jeremy Luban, professor of molecular medicine, biochemistry, and molecular biotechnology at the UMass Chan Medical School and a member of the Massachusetts Consortium on Pathogen Readiness. “It doesn’t seem to be letting up. It clearly hasn’t shot up the way the original Omicron did.”

Meanwhile, the World Health Organization is keeping an eye on another subvariant — BA.2.75 — which has been spreading in India and was detected in seven US states. But the WHO has not declared BA.2.75 a “variant of concern,” and experts said it doesn’t seem to be spreading quickly in the United States.

Last year at this time, Massachusetts was recording about 400 to 500 new COVID-19 cases a day. Today it’s harder to get a good count because so many people are testing privately at home. Even so, the state was reporting about 1,200 new cases a day last week in its most recent data release, and experts estimate probably hundreds more are being infected.

As of last week, BA.5 accounted for nearly 80 percent of cases nationwide. The subvariant transmits easily and infects those who’ve previously had COVID-19 as well as vaccinated people. But vaccination continues to protect against severe illness.

The Institute for Health Metrics and Evaluation at the University of Washington, which uses predictive modeling to preview the virus’s course, said the lack of data makes it hard to know where things are headed. But the institute said in a blog post that the BA.5 waves in Europe tended to last four to six weeks from beginning to the peak, and the United States can expect a similar pattern. The blog also said BA.5 is “probably not” a reason for great concern.

For Massachusetts, the IMHE projects a plateau of infections over the next few months, with the curve bending downward slightly in the early fall before rising gently in October.

But IMHE predicts hospital use and especially ICU use will dip to low levels in Massachusetts in August and stay low through October, as the vaccines continue to protect against serious illness.

Dr. Daniel R. Kuritzkes, chief of infectious diseases at Brigham and Women’s Hospital, said he hasn’t observed any difference between BA.5 and other recent Omicron variants in the volume or severity of illnesses. “We really seem to be in a plateau,” he said. “What’s disappointing is that the numbers haven’t gone down.”

At the Brigham, about 25 patients have COVID, and only four or five are in the ICU, mostly for other reasons. The number has been stable over the last few months, Kuritzkes said. Statewide, the number of people with COVID-19 in the hospital is four to five times greater than last July, but for the majority, COVID-19 was not the reason they were admitted.

Dr. Eric Topol, founder and director of the Scripps Research Translational Institute in La Jolla, Calif., has sounded alarms on his blog and Twitter about BA.5, saying this new subvariant is better able to evade the immune system than any previous version. Disregarding the risk “helps the virus find more people to infect,” he said in an interview. “All our behavior is doing is making things worse. We’re contributing to the virus’s success.”

BA.5 is so different from its predecessors that even people who’ve been infected with other Omicron subvariants, such as BA.1 or BA.2, are still susceptible, he said.

But others say social behaviors play a more important role in the virus’s spread than any intrinsic characteristics of the variant.

“We tend to overstate the role of the variant,” said Dr. David Rubin, director of PolicyLab at Children’s Hospital of Philadelphia. “What’s really driving these transmissions and hospitalizations is our environment and behavior.” School ended and people started traveling for vacation, he said. The hot weather drove gatherings indoors. What looks like greater transmissibility might simply be more opportunities to spread.

“I don’t think there’s any demonstrable evidence it’s a more severe variant,” he said of BA.5

Luban, the UMass scientist, agreed that “social behavior has a huge effect on the pandemic,” but it’s hard to know whether it plays a greater role than a variant’s nature.

But he does worry about uncontrolled spread. “The more those numbers go up, the virus has opportunities to do things we cannot predict,” he said.

Last fall, most experts expected that if a new surge were coming, it would be a version of the Delta variant, which was dominant at the time. “Then all of a sudden people woke up Thanksgiving morning to find there was this creature from out of the blue that was totally unrelated to Delta,” he said. That was Omicron, which brought a huge surge in cases.

“The big fear is that we’ll go through that again, that there will be something unrelated that will pop up,” Luban said.

That is Topol’s fear too. New and possibly more dangerous variants could develop in immunocompromised people or animal reservoirs, he said.

Topol called for a more aggressive and urgent federal effort to get nasal vaccines developed and approved because they will prevent transmission. Nasal vaccines have the potential to stop the virus in the upper airways, where it first enters the body, and from where infectious droplets emerge during breathing, talking, and sneezing. Additionally, he said, a major push is needed to develop a vaccine effective against any variant, as well as a medication to back up the antiviral Paxlovid, which he said would lose effectiveness as the virus develops resistance to it.

While masking, distancing, and improving air quality are all necessary, they’re insufficient, Topol said. “They’re not going to lead to the end of the pandemic,” he said.

Julia Raifman, assistant professor of health law, policy, and management at the Boston University School of Public Health, also called for more action to stop COVID’s spread. The continuing inequitable toll of COVID-19 on Black and Hispanic people and low-wage workers demands a more robust public health response, she said. Her research found that low-income workers reported missing work 12 times more, on average, than high-income workers between August 2020 and June 2022.

Each time a surge occurs, public health officials should announce it, urge vaccination and testing, and impose mask mandates — just for those high-transmission periods, Raifman said. “We need leaders to communicate when it’s important” to take precautions, she said.

Raifman also advocates for temporary mask mandates in public spaces, such as requiring masks in libraries during certain hours so elderly people and others at risk can safely visit. Designating “masked-only” cars in trains or requiring masks on certain flights would enable the vulnerable and the cautious to carry on with their lives, she said.

Despite it all, most experts remain cautiously optimistic that the pandemic will eventually settle into a predictable pattern. Even Topol expressed confidence that the new tools, like nasal vaccines, would eventually be used.

Luban feels better just looking at the declining death rates.

“There was a time when we had mobile morgues being set up around the country,” he said. “We seem to be past that, and that is huge.”

Felice J. Freyer can be reached at felice.freyer@globe.com. Follow her @felicejfreyer.