New Covid Variant Leading Surge in Respiratory Illness

By Julie Appleby, KFF Health News

It’s winter, that cozy season that brings crackling fireplaces, indoor gatherings — and a wave of respiratory illness. Nearly four years since the pandemic emerged, people are growing weary of dealing with it, but the virus is not done with us.

Nationally, a sharp uptick in emergency room visits and hospitalizations for covid-19, influenza, and respiratory syncytial virus, or RSV, began in mid-December and appears to be gaining momentum.

Here are a few things to know this time around:

What’s Circulating Now?

The covid virus is continually changing, and a recent version is rapidly climbing the charts. Even though it appeared only in September, the variant known as JN.1, a descendant of omicron, is rapidly spreading, representing between 39% to half of the cases, according to pre-holiday stats from the Centers for Disease Control and Prevention.

Lab data indicates that the updated vaccines, as well as existing covid rapid tests and medical treatments, are effective with this latest iteration. More good news is that it “does not appear to pose additional risks to public health beyond that of other recent variants,” according to the CDC.

Even so, new covid hospitalizations — 34,798 for the week that ended Dec. 30 — are trending upward, although rates are still substantially lower than last December’s tally. It’s early in the season, though. Levels of virus in wastewater — one indicator of how infections are spreading — are “very high,” exceeding the levels seen this time last year.

And don’t forget, other nasty bugs are going around. More than 20,000 people were hospitalized for influenza the week ending Dec. 30, and the CDC reports that RSV remains elevated in many areas.

“The numbers so far are definitely going in the not-so-good direction,” said Ziyad Al-Aly, the chief of the research and development service at the Veterans Affairs St. Louis Healthcare System and a clinical epidemiologist at Washington University in St. Louis. “We’re likely to see a big uptick in January now that everyone is back home from the holidays.”

Milder Cases and Fewer Deaths

Certainly, compared with the first covid winter, things are better now. Far fewer people are dying or becoming seriously ill, with vaccines and prior infections providing some immunity and reducing severity of illness.

Even compared with last winter, when omicron was surging, the situation is better. New hospitalizations, for example, are about one-third of what they were around the 2022 holidays. Weekly deaths dropped slightly the last week of December to 839 and are also substantially below levels from a year ago.

“The ratio of mild disease to serious clearly has changed,” said William Schaffner, a professor of medicine in the division of infectious diseases at Vanderbilt University School of Medicine in Nashville, Tennessee.

Even so, the definition of “mild” is broad, basically referring to anything short of being sick enough to be hospitalized.

While some patients may have no more than the sniffles, others experiencing “mild” covid can be “miserable for three to five days,” Schaffner said.

How Will This Affect My Day-to-Day Life?

“Am I going to be really sick? Do I have to mask up again?” It is important to know the basics.

For starters, symptoms of the covid variants currently circulating will likely be familiar — such as a runny nose, sore throat, cough, fatigue, fever, and muscle aches.

So if you feel ill, stay home, said Marcus Plescia, chief medical officer of the Association of State and Territorial Health Officials. “It can make a big difference.”

Dust off those at-home covid test kits, check the extended expiration dates on the FDA website, and throw away the ones that have aged out. Tests can be bought at most pharmacies and, if you haven’t ordered yours yet, free test kits are still available through a federal program at covid.gov.

Test more than once, especially if your symptoms are mild. The at-home rapid tests may not detect covid infection in the first couple of days, according to the FDA, which recommends using “multiple tests over a certain time period, such as two to three days.”

With all three viruses, those most at risk include the very young, older adults, pregnant people, and those with compromised immune systems or underlying diseases, including cancer or heart problems. But those without high-risk factors can also be adversely affected.

While mask-wearing has dropped in most places, you may start to see more people wearing them in public spaces, including stores, public transit or entertainment venues.

Although a federal mask mandate is unlikely, health officials and hospitals in at least four states — California, Illinois, Massachusetts, and New York — have again told staff and patients to don masks. Such requirements were loosened last year when the public health emergency officially ended.

Such policies are advanced through county-level directives. The CDC data indicates that, nationally, about 46.7% of counties are seeing moderate to high hospital admission rates of covid.

“We are not going to see widespread mask mandates as our population will not find that acceptable,” Schaffner noted. “That said, on an individual basis, mask-wearing is a very intelligent and reasonable thing to do as an additional layer of protection.”

The N95, KN95, and KF94 masks are the most protective. Cloth and paper are not as effective.

And, finally, if you haven’t yet been vaccinated with an updated covid vaccine or gotten a flu shot, it’s not too late. There are also new vaccines and monoclonal antibodies to protect against RSV recommended for certain populations, which include older adults, pregnant people, and young children.

Generally, flu peaks in midwinter and runs into spring. Covid, while not technically seasonal, has higher rates in winter as people crowd together indoors.

“If you haven’t received vaccines,” Schaffner said, “we urge you to get them and don’t linger.”

Repeat Infections

People who have dodged covid entirely are in the minority.

At the same time, repeat infections are common. Fifteen percent of respondents to a recent Yahoo News/YouGov poll said they’d had covid two or three times. A Canadian survey released in December found 1 in 5 residents said they had gotten covid more than once as of last June.

Aside from the drag of being sick and missing work or school for days, debate continues over whether repeat infections pose smaller or larger risks of serious health effects. There are no definitive answers, although experts continue to study the issue.

Two research efforts suggest repeat infections may increase a person’s chances of developing serious illness or even long covid — which is defined various ways but generally means having one or more effects lingering for a month or more following infection. The precise percentage of cases — and underlying factors — of long covid and why people get it are among the many unanswered questions about the condition. However, there is a growing consensus among researchers that vaccination is protective.

Still, the VA’s Al-Aly said a study he co-authored that was published in November 2022 found that getting covid more than once raises an “additional risk of problems in the acute phase, be it hospitalization or even dying,” and makes a person two times as likely to experience long covid symptoms.

The Canadian survey also found a higher risk of long covid among those who self-reported two or more infections. Both studies have their limitations: Most of the 6 million in the VA database were male and older, and the data studied came from the first two years of the pandemic, so some of it reflected illnesses from before vaccines became available. The Canadian survey, although more recent, relied on self-reporting of infections and conditions, which may not be accurate.

Still, Al-Aly and other experts say taking preventive steps, such as getting vaccinated and wearing a mask in higher-risk situations, can hedge your bets.

“Even if in a prior infection you dodged the bullet of long covid,” Al-Aly said, “it doesn’t’ mean you will dodge the bullet every single time.”

KFF Health News is a national newsroom that produces in-depth journalism about health issues.

Is Another Covid Spike Coming? 6 Tips to Help You Stay Safe

By Celine Gounder, Kaiser Health News

The emergence last year of the highly transmissible omicron variant of the covid-19 virus caught many people by surprise, and led to a surge in cases that overwhelmed hospitals and drove up fatalities. Now we’re learning that omicron is mutating further to better evade the immune system.

Omicron-specific vaccines were authorized by the FDA in August and are recommended by U.S. health officials for anyone 5 or older. Yet only half of adults in the United States have heard much about these booster shots, according to a recent Kaiser Family Foundation poll, and only a third say they’ve gotten one or plan to get one as soon as possible. In 2020 and 2021, covid cases spiked in the U.S. between November and February.

Although we don’t know for sure that we’ll see another surge this winter, here’s what you should know about covid and the updated boosters to prepare.

1. Do I need a covid booster shot this fall?

If you’ve completed a primary vaccination series and are 50 or older, or if your immune system is compromised, get a covid booster shot as soon as possible. Forty percent of deaths are occurring among people 85 and older and almost 90% among people 65 and over. Although people of all ages are being hospitalized from covid, those hospitalizations are also skewing older.

Unvaccinated people, while in the minority in the U.S., are still at the highest risk of dying from covid. It’s not too late to get vaccinated ahead of this winter season. The United Kingdom, whose covid waves have presaged those in the United States by about a month, is beginning to see another increase in cases.

If you’ve already received three or more covid shots, you’re 12 to 49 years old, and you’re not immunocompromised, your risk of hospitalization and death from the disease is significantly reduced and additional boosters are not likely to add much protection.

However, getting a booster shot provides a “honeymoon” period for a couple of months after vaccination, during which you’re less likely to get infected and thus less likely to transmit the virus to others. If you’ll be seeing older, immunocompromised, or otherwise vulnerable family and friends over the winter holidays, you might want to get a booster two to four weeks in advance to better shield them against covid.

You may have other reasons for wanting to avoid infection, like not wanting to have to stay home from work because you or your child is sick with covid. Even if you aren’t hospitalized from covid, it can be costly to lose wages or arrange for backup child care.

One major caveat to these recommendations: You should wait four to six months after your last covid infection or vaccination before getting another shot. A dose administered too soon will be less effective because antibodies from the previous infection or vaccination will still be circulating in your blood and will prevent your immune cells from seeing and responding to vaccination.

2. Do kids need to be vaccinated even if they’ve had covid?

Although children are at lower risk for severe covid than are adults, the stakes for kids are higher than many diseases already recognized as dangerous. Their risk shouldn’t be measured against the risk that covid poses to other age groups but against the risk they face from other preventable diseases.

In the first two years of the pandemic, covid was the fourth- or fifth-leading cause of death in every five-year age bracket from birth to 19, killing almost 1,500 children and teenagers. Other vaccine-preventable diseases like chickenpox, rubella, and rotavirus killed an average of about 20-50 children and teens a year before vaccines became available. By that measure, vaccinating kids against covid is a slam-dunk.

Children who have had covid also benefit from vaccination. The vaccine reduces their risk of hospitalization and missing days of school, when parents might need to stay home with them.

But it’s precisely because the stakes are higher for kids that many parents are anxious about getting their children vaccinated. As recently as July, just after the FDA authorized covid vaccines for children as young as 6 months, a KFF poll found that over half of parents of children under age 5 said they thought vaccines posed a greater risk to the health of their child than getting the disease. And in the most recent poll, half said they had no plans to get their children vaccinated. Covid vaccination rates range from 61% among children ages 12 to 17 to 2% among kids younger than 2.

Similar to influenza, covid is most deadly for the very youngest and oldest. At especially high risk are infants. They’re unlikely to have immunity from infection, and a small share have been vaccinated. Unless their mothers were vaccinated during pregnancy or got covid during pregnancy — the latter of which poses a high risk of death for the mother and of preterm birth for the baby — infants are probably not getting protective antibodies against covid through breast milk. And because infants have small airways and weaker coughs, they’re more likely to have trouble breathing with any respiratory infection, even one less deadly than covid.

3. Will I need a covid shot every year?

It depends on the targets set by public health officials whether covid becomes a seasonal virus like the flu, and how much the virus continues to mutate and evade humanity’s immune defenses.

If the goal of vaccination is to prevent severe disease, hospitalization, and death, then many people will be well protected after their primary vaccination series and may not need additional shots. Public health officials might strongly recommend boosters for older and immunocompromised people while leaving the choice of whether to get boosted to those with lower risk. If the goal of vaccination is to prevent infection and transmission, then repeat boosters will be needed after completing the primary vaccination series and as often as a couple of times a year.

Influenza is a seasonal virus causing infections and disease generally in the winter, but scientists don’t know whether covid will settle into a similar, predictable pattern. In the first three years of the pandemic, the United States has experienced waves of infection in summer. But if the covid virus were to become a wintertime virus, public health officials might recommend yearly boosters. The Centers for Disease Control and Prevention recommends that people 6 months and older get a flu shot every year with very rare exceptions. However, as with the flu, public health officials might still place a special emphasis on vaccinating high-risk people against covid.

And the more the virus mutates, the more often public health officials may recommend boosting to overcome a new variant’s immune evasion. Unfortunately, this year’s updated omicron booster doesn’t appear to provide significantly better protection than the original boosters. Scientists are working on variant-proof vaccines that could retain their potency in the face of new variants.

4. Are more covid variants on the way?

The omicron variant has burst into an alphabet soup of subvariants. The BA.5 variant that surfaced earlier this year remains the dominant variant in the U.S., but the BA.4.6 omicron subvariant may be poised to become dominant in the United States. It now accounts for 14% of cases and is rising. The BA.4.6 omicron subvariant is better than BA.5 at dodging people’s immune defenses from both prior infection and vaccination.

In other parts of the world, BA.4.6 has been overtaken by BA.2.75 and BF.7 (a descendant of BA.5), which respectively account for fewer than 2% and 5% of covid cases in the U.S. The BA.2.75.2 omicron subvariant drove a wave of infections in South Asia in July and August. Although the U.S. hasn’t yet seen much in the way of another variant descended from BA.5 — BQ.1.1 — it is rising quickly in other countries like the U.K., Belgium, and Denmark. The BA.2.75.2 and BQ.1.1 variants may be the most immune-evasive omicron subvariants to date.

BA.4.6, BA.2.75.2, and BQ.1.1 all evade Evusheld, the monoclonal antibody used to prevent covid in immunocompromised people who don’t respond as well to vaccination. Although another medication, bebtelovimab, remains active in treating covid from BA.4.6 and BA.2.75.2, it’s ineffective against BQ.1.1. Many scientists are worried that Evusheld will become useless by November or December. This is concerning because the pipeline for new antiviral pills and monoclonal antibodies to treat covid is running dry without a guaranteed purchaser to ensure a market. In the past, the federal government guaranteed it would buy vaccines in bulk, but funding for that program has not been extended by Congress.

Other omicron subvariants on the horizon include BJ.1, BA.2.3.20, BN.1, and XBB, all descendants of BA.2.

It’s hard to predict whether an omicron subvariant or yet another variant will come to dominate this winter and whether hospitalizations and deaths will again surge in the U.S. Vaccination rates and experience with prior infections vary around the world and even within the United States, which means that the different versions of omicron are duking it out on different playing fields.

While this might all sound grim, it’s important to remember that covid booster shots can help overcome immune evasion by the predominant omicron subvariants.

5. What about long covid?

Getting vaccinated does reduce the risk of getting long covid, but it’s unclear by how much. Researchers don’t know if the only way to prevent long covid is to prevent infection.

Although vaccines may curb the risk of infection, few vaccines prevent all or almost all infections. Additional measures — such as improving indoor air quality and donning masks — would be needed to reduce the risk of infection. It’s also not yet known whether prompt treatment with currently available monoclonal antibodies and antiviral drugs like Paxlovid reduces the risk of developing long covid.

6. Do I need a flu shot, too?

The CDC recommends that anyone 6 months of age or older get an annual flu shot. The ideal timing is late October or early November, before the winter holidays and before influenza typically starts spreading in the U.S. Like covid shots, flu shots provide only a couple of months of immunity against infection and transmission, but an early flu shot is better than no flu shot. Influenza is already circulating in some parts of the United States.

It’s especially important for people 65 or older, pregnant women, people with chronic medical conditions, and children under 5 to get their yearly flu shots because they’re at highest risk of hospitalization and death. Although younger people might be at lower risk for severe flu, they can act as vectors for transmission of influenza to higher-risk people in the community.

High-dose flu vaccines and “adjuvanted” flu vaccines are recommended for people 65 and older. Adjuvants strengthen the immune response to a vaccine. It is safe to get vaccinated for covid and the flu at the same time, but you might experience more side effects like fevers, headache, or body aches.

Kaiser Health News is a national newsroom that produces in-depth journalism about health issues.

The ‘Parallel Pandemic’ of Long Covid

By Liz Szabo, Kaiser Health News

The latest covid-19 surge, caused by a shifting mix of quickly evolving omicron subvariants, appears to be waning, with cases and hospitalizations beginning to fall. Like past covid waves, this one will leave a lingering imprint in the form of long covid, an ill-defined catchall term for a set of symptoms that can include debilitating fatigue, difficulty breathing, chest pain, and brain fog.

Although omicron infections are proving milder overall than those caused by last summer’s delta variant, omicron has also proved capable of triggering long-term symptoms and organ damage. But whether omicron causes long covid symptoms as often — and as severe — as previous variants is a matter of heated study.

Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy, is among the researchers who say the far greater number of omicron infections compared with earlier variants signals the need to prepare for a significant boost in people with long covid.

The U.S. has recorded nearly 38 million covid infections so far this year, as omicron has blanketed the nation. That’s about 40% of all infections reported since the start of the pandemic, according to the Johns Hopkins University Coronavirus Research Center.

Long covid “is a parallel pandemic that most people aren’t even thinking about,” said Akiko Iwasaki, a professor of immunobiology at Yale University. “I suspect there will be millions of people who acquire long covid after omicron infection.”

Scientists have just begun to compare variants head-to-head, with varying results. While one recent study in The Lancet suggests that omicron is less likely to cause long covid, another found the same rate of neurological problems after omicron and delta infections.

Estimates of the proportion of patients affected by long covid also vary, from 4% to 5% in triple-vaccinated adults to as many as 50% among the unvaccinated, based on differences in the populations studied.

One reason for that broad range is that long covid has been defined in widely varying ways in different studies, ranging from self-reported fogginess for a few months after infection to a dangerously impaired inability to regulate pulse and blood pressure that may last years. Even at the low end of those estimates, the sheer number of omicron infections this year would swell long-covid caseloads.

“That’s exactly what we did find in the UK,” said Claire Steves, a professor of aging and health at King’s College in London and author of the Lancet study, which found patients have been 24% to 50% less likely to develop long covid during the omicron wave than during the delta wave.

“Even though the risk of long covid is lower, because so many people have caught omicron, the absolute numbers with long covid went up,” Steves said.

Reinfections Raise Risk

A recent study analyzing a patient database from the Veterans Health Administration found that reinfections dramatically increased the risk of serious health issues, even in people with mild symptoms. The study of more than 5.4 million VA patients, including more than 560,000 women, found that people reinfected with covid were twice as likely to die or have a heart attack as people infected only once. And they were far more likely to experience health problems of all kinds as of six months later, including trouble with their lungs, kidneys, and digestive system.

“We’re not saying a second infection is going to feel worse; we’re saying it adds to your risk,” said Dr. Ziyad Al-Aly, chief of research and education service at the Veterans Affairs St. Louis Health Care System.

Researchers say the study, published online but not yet peer-reviewed, should be interpreted with caution. Some noted that VA patients have unique characteristics, and tend to be older men with high rates of chronic conditions that increase the risks for long covid. They warned that the study’s findings cannot be extrapolated to the general population, which is younger and healthier overall.

“We need to validate these findings with other studies,” said Dr. Harlan Krumholz, director of the Yale New Haven Hospital Center for Outcomes Research and Evaluation. Still, he added, the VA study has some “disturbing implications.”

With an estimated 82% of Americans having been infected at least once with the coronavirus as of mid-July, most new cases now are reinfections, said Justin Lessler, a professor of epidemiology at the University of North Carolina Gillings School of Global Public Health.

‘Breathing Through a Straw’

Of course, people’s risk of reinfection depends not just on their immune system, but also on the precautions they’re taking, such as masking, getting booster shots, and avoiding crowds.

New Jersey salon owner Tee Hundley, 43, has had covid three times, twice before vaccines were widely available and again this summer, after she was fully vaccinated. She is still suffering the consequences.

After her second infection, she returned to work as a cosmetologist at her Jersey City salon but struggled with illness and shortness of breath for the next eight months, often feeling like she was “breathing through a straw.”

She was exhausted, and sometimes slow to find her words. While waxing a client’s eyebrows, “I would literally forget which eyebrow I was waxing,” Hundley said. “My brain was so slow.”

When she got a breakthrough infection in July, her symptoms were short-lived and milder: cough, runny nose, and fatigue. But the tightness in her chest remains.

“I feel like that’s something that will always be left over,” said Hundley, who warns friends with covid not to overexert. “You may not feel terrible, but inside of your body there is a war going on.”

Although each omicron subvariant has different mutations, they’re similar enough that people infected with one, such as BA.2, have relatively good protection against newer versions of omicron, such as BA.5. People sickened by earlier variants are far more vulnerable to BA.5.

Several studies have found that vaccination reduces the risk of long covid. But the measure of that protection varies by study, from as little as a 15% reduction in risk to a more than 50% decrease. A study published in July found the risk of long covid dropped with each dose people received.

For now, the only surefire way to prevent long covid is to avoid getting sick. That’s no easy task as the virus mutates and Americans have largely stopped masking in public places. Current vaccines are great at preventing severe illness but do not prevent the virus from jumping from one person to the next.

Scientists are working on next-generation vaccines — “variant-proof” shots that would work on any version of the virus, as well as nasal sprays that might actually prevent spread. If they succeed, that could dramatically curb new cases of long covid.

“We need vaccines that reduce transmission,” Al-Aly said. “We need them yesterday.”

Kaiser Health News is a national newsroom that produces in-depth journalism about health issues.

Covid’s New Wave: Get Another Booster Shot or Wait?

By Sam Whitehead and Arthur Allen, Kaiser Health News

Gwyneth Paige didn’t want to get vaccinated against covid-19 at first. With her health issues — hypertension, fibromyalgia, asthma — she wanted to see how other people fared after the shots. Then her mother got colon cancer.

“At that point, I didn’t care if the vaccine killed me,” she said. “To be with my mother throughout her journey, I had to have the vaccination.”

Paige, who is 56 and lives in Detroit, has received three doses. That leaves her one booster short of federal health recommendations.

Like Paige, who said she doesn’t currently plan to get another booster, some Americans seem comfortable with the protection of three shots. But others may wonder what to do: Boost again now with one of the original vaccines, or wait months for promised new formulations tailored to the latest, highly contagious omicron subvariants, BA.4 and BA.5?

The rapidly mutating virus has created a conundrum for the public and a communications challenge for health officials.

“What we’re seeing now is a little bit of an information void that is not helping people make the right decision,” said Dr. Carlos del Rio, a professor of infectious diseases at the Emory University School of Medicine.

Del Rio said the public isn’t hearing enough about the vaccines’ value in preventing severe disease, even if they don’t stop all infections. Each new covid variant also forces health officials to tweak their messaging, del Rio said, which can add to public mistrust.

About 70% of Americans age 50 and older who got a first booster shot — and nearly as many of those 65 and older — haven’t received their second covid booster dose, according to data from the Centers for Disease Control and Prevention. The agency currently recommends two booster shots after a primary vaccine series for adults 50 and older and for younger people with compromised immune systems. Last week, multiple news outlets reported that the Biden administration was working on a plan to allow all adults to get second covid boosters.

Officials are worried about the surge of BA.4 and BA.5, which spread easily and can escape immune protection from vaccination or prior infection. A recent study published in Nature found BA.5 was four times as resistant to the currently available mRNA vaccines as earlier omicron subvariants.

Mixed Messages

Consistent messaging has been complicated by the different views of leading vaccine scientists. Although physicians like del Rio and Dr. Peter Hotez of Baylor College of Medicine see the value in getting a second booster, Dr. Paul Offit, a member of the FDA’s vaccine advisory committee, is skeptical it’s needed by anyone but seniors and people who are immunocompromised.

“When experts have different views based on the same science, why are we surprised that getting the message right is confusing?” said Dr. Bruce Gellin, chief of global public health strategy at the Rockefeller Foundation and Offit’s colleague on the FDA panel.

Janet Perrin, 70, of Houston hasn’t gotten her second booster for scheduling and convenience reasons and said she’ll look for information about a variant-targeted dose from sources she trusts on social media. “I haven’t found a consistent guiding voice from the CDC,” she said, and the agency’s statements sound like “a political word salad.”

On July 12, the Biden administration released its plan to manage the BA.5 subvariant, which it warned would have the greatest impact in the parts of the country with lower vaccine coverage. The strategy includes making it easier for people to access testing, vaccines and boosters, and covid antiviral treatments.

During the first White House covid briefing in nearly three weeks, the message from top federal health officials was clear: Don’t wait for an omicron-tailored shot. “There are many people who are at high risk right now, and waiting until October, November for their boost — when in fact their risk is in the moment — is not a good plan,” said Dr. Rochelle Walensky, head of the CDC.

With worries about the BA.5 subvariant growing, the FDA on June 30 recommended that drugmakers Pfizer-BioNTech and Moderna get to work producing a new, bivalent vaccine that combines the current version with a formulation that targets the new strains.

The companies both say they can make available for the U.S. millions of doses of the reformulated shots in October. Experts think that deadline could slip by a few months given the unexpected hitches that plague vaccine manufacturing.

“I think that we have all been asking that same question,” said Dr. Kathryn Edwards, scientific director of the Vanderbilt Vaccine Research Program. “What’s the benefit of getting another booster now when what will be coming out in the fall is a bivalent vaccine and you will be getting BA.4/5, which is currently circulating?”

There are many people who are at high risk right now, and waiting until October, November for their boost — when in fact their risk is in the moment — is not a good plan.
— Dr. Rochelle Walensky, CDC.Director

The FDA on July 13 authorized a fourth covid vaccine, made by Novavax, but only for people who haven’t been vaccinated yet. Many scientists thought the Novavax shot could be an effective booster for people previously vaccinated with mRNA shots from Pfizer-BioNTech and Moderna because its unique design could broaden the immune response to coronaviruses. Unfortunately, few studies have assessed mix-and-match vaccination approaches, said Gellin, of the Rockefeller Foundation.

Edwards and her husband got covid in January. She received a second booster last month, but only because she thought it might be required for a Canadian business trip. Otherwise, she said, she felt a fourth shot was kind of a waste, though not particularly risky. She told her husband — a healthy septuagenarian — to wait for the BA.4/5 version.

People at very high risk for covid complications might want to go ahead and get a fourth dose, Edwards said, with the hope that it will temporarily prevent severe disease “while you wait for BA.4/5.”

The omicron vaccines will contain components that target the original strain of the virus because the first vaccine formulations are known to prevent serious illness and death even in people infected with omicron.

Those components will also help keep the earlier strains of the virus in check, said Dr. David Brett-Major, an infectious disease specialist at the University of Nebraska Medical Center. That’s important, he said, because too much tailoring of vaccines to fight emerging variants could allow older strains of the coronavirus to resurface.

Brett-Major said messages about the value of the tailored shots will need to come from trusted, local sources — not just top federal health officials.

“Access happens locally,” he said. “If your local systems are not messaging and promoting and enabling access, it’s really problematic.”

Although some Americans are pondering when, or whether, to get their second boosters, many people tuned out the pandemic long ago, putting them at risk during the current wave, experts said.

Dr. Georges Benjamin, executive director of the American Public Health Association, said he doesn’t expect to see the public’s level of interest in the vaccine change much even as new boosters are released and eligibility expands. Parts of the country with high vaccine coverage will remain relatively insulated from new variants that emerge, he said, while regions with low vaccine acceptance could be set for a “rude awakening.”

Even scientists are at a bit of a loss for how to effectively adapt to an ever-changing virus.

“Nothing is simple with covid, is it? It’s just whack-a-mole,” said Edwards. “This morning I read about a new variant in India. Maybe it’ll be a nothingburger, but — who knows? — maybe something big, and then we’ll wonder, ‘Why did we change the vaccine strain to BA.4/5?’”

Kaiser Health News is a national newsroom that produces in-depth journalism about health issues.