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 subvariants circulating at that time. The Centers for Disease Control and Prevention said the new booster, known as the bivalent COVID-19 vaccine, currently provides the highest protection against the virus.
But adoption has been low. Even though the bivalent booster has been shown to be safe and to increase protection against infection and serious illness, so far only 16% of Americans have received it.
However, many early adopters of vaccines arrive six months after vaccination and are now wondering if they need a second dose, and if so, when.
“It’s probably the most common question I get asked: ‘Hey, doc, I had this in September. It’s been a few months. Shouldn’t I get another reminder now?'” A Dr. Peter Hotez, co-director of the Texas Children’s Hospital Center for Vaccine Development and dean of the National School of Tropical Medicine at Baylor College of Medicine, told Yahoo News.
On Tuesday, vaccine advisers in the UK recommended a spring booster dose for high-risk groups, including people over 75, immunocompromised or residents of nursing homes.
Many first users of the bivalent vaccine do not want to wait until the fall
Federal health agencies such as the Food and Drug Administration and the CDC have not officially recommended the need for a second bivalent booster dose at this time. However, the FDA recently proposed moving to an annual COVID-19 booster plan, similar to the flu model. Under this strategy, most healthy people will receive a dose each fall. The agency said some Americans, including the elderly, unvaccinated young children and those who are immunocompromised, may need to be offered two or more doses per year.
Paula Lazor, 68, of Arlington, Va., told Yahoo News that she and her husband – who is 75 and has underlying health conditions – received the bivalent booster as soon as he is became available. They are now both eager to get a second dose.
“My husband and I are very keen on the idea of getting a second bivalent vaccine. In fact, we had planned to contact our treating doctor next week … to see if this is possible,” Lazor said, adding that she wanted her family to have the highest possible protection against the virus.
The CDC has repeatedly reaffirmed that the primary goal of the country’s COVID-19 vaccination strategy is to prevent serious illness, but people like Lazor also fear contracting “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 dual-recall protection may be waning is not unfounded, given what we know about past recalls.
Booster doses were first recommended in fall 2021 for high-risk groups. The initial boosters were the same formulation as the primary series, which was designed to target only the original strain of the virus. This is also known as a monovalent vaccine. Although these vaccines have been shown to be highly effective in protecting people from serious illness and death, scientific evidence has begun to show that vaccine effectiveness against COVID-19 hospitalization declines over time. This reduction in protection was significant, especially for people aged 65 and over. Experts said the decline in vaccine effectiveness is likely due to a combination of factors, including waning 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 go down after about five months,” Hotez explained. If bivalent boosters are similar, he said, “we’re getting closer to that time, and that’s why I think it’s important for the CDC or the FDA or both to issue a statement, so we know where we are at this point.”
Not enough data to make a recommendation at this time, 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 COVID-19 injections. During the meeting, the agency presented some data on the effectiveness of the bivalent booster dose.
According to these data, bivalent vaccines continue to provide protection against hospitalizations, but protection against infection appears to decline over time, particularly in the elderly. But the agency said: “The decline of bivalent EV (vaccine effectiveness) against hospitalization, including in 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” available to make a recommendation on whether older people and those who are immunocompromised need a another booster dose at this time. They noted, however, that this may change in the future.
But some experts believe federal health agencies should at least authorize the additional booster dose so people have the option to choose for themselves – especially because community transmission continues to be high in many parts of the country. , according to CDC data.
At a recent COVID-19 vaccine expert meeting hosted by the Johns Hopkins Bloomberg School of Public Health, Dr. William Moss, a professor in the departments of Epidemiology and International Health as well as Molecular Microbiology and Immunology of this institution, told Yahoo News that allowing another bivalent booster shot for vulnerable populations would be a good idea.
“Officially, there is no recommendation yet for an additional booster dose for these people, but from what we have said, I think it would be entirely reasonable in vulnerable populations, for whom the last recall goes back a while,” Moss said. . “There would have been a decrease in protective immunity, certainly against mild and possibly moderate disease. There is no right answer. It will also depend on the level of community transmission, but I would say that would be a reasonable consideration. »
Dr Monica Gandhi, an infectious disease specialist and professor of medicine at the University of California, San Francisco, said it’s understandable for the elderly or immunocompromised to worry about not knowing when they can get another booster. bivalent. But she said some studies have shown that the initial doses of vaccines still do a good job of protecting against serious illnesses. Additionally, she said the COVID antiviral pill Paxlovid continues to be an important tool for people in high-risk groups who catch the virus.
“I would say that the original doses of the vaccines you received seem to be working very well, and I wouldn’t be concerned about needing another dose until the fall, based on the level of evidence we have” , said Gandhi.