New variants, boosters and more: Your expert guide to COVID-19 as fall approaches

Wastewater detection levels of the coronavirus in the Greater Boston area have been rising for more than a month, and there's a been a recent uptick in COVID-19 hospitalizations in Massachusetts.

Given these increases and the fact that fall and winter have brought the biggest surges in cases so far in the COVID-19 pandemic, as the summer comes to end, you may be wondering what to expect.

Here are some key takeaways from local public health experts.

Is COVID on the rise again?

Yes, but it’s important to keep any absolute numbers in perspective. Some key metrics that we use to assess how much of the coronavirus is circulating — including MWRA wastewater data and statewide hospitalizations — are higher than they were earlier in summer, but remain below the peaks of past surges.

Dr. Shira Doron, chief infection control officer at Tufts Medicine, said the number of patients with severe COVID-19 at their main Boston hospital has remained in the single digits since May, when they had their first day with zero such patients.

“Two patients in the hospital compared to the 90 that we've had [during surges] is really not a big number for us. And of course, it's very manageable from a health care standpoint,” she said.

Dr. Sabrina Assoumou, an infectious disease physician at Boston Medical Center, and an associate professor of medicine at Boston University, agreed the situation in Massachusetts is very different than it was in the early stages of the COVID-19 pandemic when deaths were high, and clinicians like her felt helpless.

“That’s the way I would look at it, that, yes, there's more virus circulating. Yes, the virus, it is evolving,” Assoumou said. “It will continue to evolve. But we do have a lot of tools and a lot of lessons that we've learned to help us sort of move forward.”

Should we expect yet another fall or winter surge?

Assoumou said people's immune responses are better equipped now than in years past. Still, if there’s one thing about the coronavirus a health expert will always remind you: It's the virus' ability to shift.

“I hope, and I don't expect to see large surges,” she said. “But, you know, this virus has surprised us; we've learned to be humble.”

What are the new COVID-19 strains?

All currently circulating variants are in the omicron family.

XBB.1.5 exploded in the United States at the end of 2022 and was the dominant strain here through the end of July. It was able to spread rapidly and has a moderate ability to evade previous immunity, but does not carry additional risk of severe disease.

XBB.1.16 appeared in January. So far, it's been more prevalent overseas than in the United States. The WHO notes that XBB.1.16 has a moderate ability to spread and evade previous immunity, but it also does not appear to cause more severe disease.

BA.2.86, nicknamed " Pirola" on social media, was first documented in July. It has shown up in a few places overseas, and at least two cases of infection with this subvariant have been identified in the United States. BA.2.86 has public health experts preliminarily concerned because of the number and type of mutations it’s shown.

There are few known cases of infection. The Centers for Disease Control and Prevention cautions that much remains unknown about the BA.2.86 variant, including whether it may cause more severe illness or be more transmissible than other strains. But based on the timing of when it was identified, the CDC does not believe the BA.2.86 variant has driven the recent increase in U.S. hospitalizations.

EG.5, informally called "Eris" after the Greek goddess of discord, is also a descendant of the XBB line. It has been circulating worldwide since being identified in February. It's appeared in 51 countries, including the United States. The EG.5 variant was responsible for about 19% of cases in the Northeast U.S. as of mid-August, according to CDC data.

But while EG.5 is widespread, the World Health Organization said it has not been linked to more severe illness and it does not pose any additional risk compared to other circulating COVID variants.

FL.1.5.1, nicknamed "Fornax," is currently the most prevalent strain in the region. It accounted for 23.5% of cases in the Northeast U.S. in mid-August, according to CDC data.

How can I protect myself against these variants?

Currently, the most prevalent variants are in the omicron family and appear to spread in the same ways as prior variants.

Doron emphasized that because of high vaccination rates and previous infections, there is a “wall of community immunity” in Massachusetts that is preventing most current cases from becoming severe.

“Our immune system is brilliant: it evolves also when the virus is evolving,” Assoumou explained. “If you've been vaccinated and you've seen this virus, your body is able to sort of respond and tailor things.”

Assoumou recommended masking in crowded places and taking a COVID-19 test when you have respiratory illness symptoms like a cough, runny nose or sore throat. Precautionary masking and testing, she said, can go a long way to forestalling another surge.

The main message from experts continues to be: even if there’s a lot of COVID-19 cases, they don’t expect a lot of deaths or severe illness, and especially for people who are not in high-risk categories.

“We have antivirals, we have Paxlovid,” Assoumou said. “And if there's actually one message that we need to make sure that gets through is that Paxlovid works if you qualify for it. So if you get infected, I would say call your doctor ... It works very well, it would prevent you from needing to be hospitalized.”

Well what about the fall vaccines? Who should get a 2023 COVID booster?

The fall COVID-19 vaccines specifically target the XBB.1.5 variant. Moderna reported that clinical trial data showed its new formula also protects against the XBB family variants more prevalent right now: EG.5 and FL.1.5.1. Pfizer and Novavax have also said their fall boosters show effectiveness against EG.5.

These booster shots may be available by mid-September.

There are a few regulatory hurdles left. First, the FDA needs to sign off on the new formulas. Then a panel of advisors to the CDC will discuss whether to recommend the updated shots. After that, the CDC needs to sign off on those recommendations in order for the vaccines to be made available to the public.

“If you're worried about this virus, the number one thing to do is that you are up to date with your vaccinations,” Assoumou said. “That's how you protect yourself and your family.”

For now, the best advice is if you are in a high-risk category, you should get an updated vaccine. People at higher risk of severe disease include older adults, those with certain medical conditions, and those with weakened immune systems.

Are we reaching endemicity, when we could treat COVID-19 more like the flu?

Assoumou said we’ll only know when COVID-19 is endemic by looking in the rear-view mirror, because there’s no way to assess endemicity in real time.

And she cautioned that reaching a manageable level of COVID-19 is not an end point.

“Endemic doesn't mean mild or without consequences, right?” Assoumou said. “We can see a condition that's endemic that still causes a lot of havoc.”

Assoumou said she believes COVID-19 may get into a rhythm of quieting down in spring and summer, and then picking up in fall, but she was quick to say it has not become seasonal like the flu in any predictable way.

Still, Doron said we need to be “moving toward treating it like an endemic virus.” She noted that the proportion of people dying from COVID-19 is much lower than it once was, but it's still occurring year-round.

For right now, Doron and Assoumou agreed you should take routine precautions to protect yourself and others: testing when you’re sick, masking when necessary, and being up to date on your vaccines.