Is another bivalent COVID booster vaccine on the way? Here’s what we know

A woman receives a booster for COVID-19. (Getty Images)

Last fall, US health officials authorized new COVID-19 booster shots designed to target the original strain of the coronavirus and some of the Omicron sub-variants that were circulating at the time. The Centers for Disease Control and Prevention said the new booster vaccine, known as the bivalent COVID-19 vaccine, offers the highest protection against the virus at the moment.

But uptake is low. Although the bivalent booster has been shown to be safe and increase protection against infection and serious illness, so far only 16% of Americans have received it.

However, many of those who received the early shots come six months post-vaccination and are now wondering if they need a second dose and if so, when.

“That’s probably the most common question I get asked, ‘Hey doc, I got this in September. It’s been a few months. Shouldn’t I already be getting another booster?” Dr. Peter Hotez, co-director of the Texas Children’s Hospital Vaccine Development Center and dean of the National School of Tropical Medicine at Baylor College of Medicine, told Yahoo News.

On Tuesday, UK vaccine advisers recommended a spring booster dose for high-risk groups, including those over 75, immunosuppressed or nursing home residents.

Many early adopters of the bivalent vaccine don’t want to wait until the fall

Federal health agencies such as the Food and Drug Administration and the CDC have not made an official recommendation on whether a second bivalent booster dose is needed at this time. However, the FDA recently proposed moving to an annual booster plan for COVID-19, similar to the flu model. Under this strategy, most healthy people will receive one dose each fall. The agency said some Americans, including the elderly, unvaccinated young children and the immunocompromised, may need to be offered two or more doses a year.

Paula Lazor, 68, of Arlington, Virginia, told Yahoo News that she and her husband — who is 75 and has underlying health problems — got the bivalent booster as soon as it became available. Now they are both eager to get a second dose.

“My husband and I are very determined to get a second bivalent injection. We were actually planning on contacting our primary care doctor next week … to see if that’s possible,” Lazor said, adding that she wants her family to have the highest possible protection against the virus.

The CDC has confirmed several times that the main goal of the country’s COVID-19 vaccination strategy is to prevent severe illness, but people like Lazor also worry about getting “long COVID” and making others sick.

“We especially don’t want to pass this virus on to our grandchildren,” she said.

Lazor’s concern that the protection of the bivalent booster shot may be weakening by now is not unfounded given what we know about previous boosters.

Booster doses were first recommended in fall 2021 for high-risk groups. The initial boosters were of the same formula as the primary series, which was intended to target only the original strain of the virus. This is also known as a monovalent vaccine. Although these shots have proven to be very effective in protecting people against severe illness and death, scientific evidence has begun to show that the effectiveness of the vaccine against hospitalization for COVID-19 declines over time. This reduction in protection is particularly significant for those aged 65 and over. Experts said the decline in vaccine effectiveness is likely due to a combination of factors, including weakening immunity and the emergence of new variants.

“In the past for monovalent boosters, when you look at some of the data, the protection against hospitalization starts to drop off after about five months,” Hotez explained. If bivalent boosters are similar, he said, “we’re getting closer to that time, and so I think it’s important that CDC or FDA or both issue a statement so we know where we are at this point.”

There aren’t enough data to make a recommendation at this time, the CDC says

The CDC’s Advisory Committee on Immunization Practices — a group of outside experts who advise the agency on vaccines — recently met to discuss vaccines against COVID-19. During the meeting, the agency presented some data on the effectiveness of the bivalent booster dose.

According to these data, bivalent vaccines continue to offer protection against hospitalizations, but protection against infection appears to wane over time, particularly among the elderly. But the agency said: “Weakening for divalent VE [vaccine effectiveness] against hospitalization, including among the elderly, is not yet known.” This is partly because not enough time has passed since the shot was deployed. At the end of the meeting, the group of scientists concluded that there was “insufficient evidence” to make a recommendation on whether older people and those with weakened immune systems needed another booster dose at this time. However, they noted that this could change in the future.

But some experts believe federal health agencies should at least allow the extra booster dose so people can make their own choices — especially because community transmission remains high in many areas of the country, according to CDC data.

At an expert briefing on COVID-19 vaccines held recently by the Johns Hopkins Bloomberg School of Public Health, Dr. William Moss, a professor in the departments of epidemiology and international health, and molecular microbiology and immunology at that institution, told Yahoo News that allowing another bivalent booster injection for vulnerable populations would be a reasonable idea.

“Officially there is still no recommendation for an additional booster dose for these individuals, but based on what we are saying, I think it would be quite reasonable in vulnerable populations for whom the last booster dose was some time ago,” Moss said . “There will be some waning of protective immunity, certainly against mild and perhaps moderate disease. There is no right answer. This would also depend on the level of transmission in the community, but I would say that would be a reasonable consideration.

Dr. Monica Gandhi, an infectious disease specialist and professor of medicine at UC San Francisco, said it’s understandable that the elderly or immunocompromised feel anxious about not knowing when they might get another bivalent booster. But she said some studies show that the initial doses of the vaccines still do a good job of protecting them from severe disease. In addition, she said the antiviral drug against COVID Paxlovid continues to be an important tool for those in high-risk groups who catch the virus.

“I would say that the initial doses of the vaccines that you received seem to be working very well, and I wouldn’t be concerned about needing another dose before the fall, based on the level of evidence that we have,” Gandy said.

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