Will there be another round of bivalent boosters against COVID-19?

by time news

Dubai, United Arab Emirates (CNN) — US officials are considering whether to offer people at high risk of COVID-19 the chance to get another bivalent booster, according to a source familiar with the ongoing discussions.

Many people trying to protect themselves or their loved ones from severe illness are wondering when they will get another shot, including Michael Osterholm, who directs the University of Minnesota Center for Infectious Disease Research and Prevention.

The 70-year-old got an updated bivalent booster as soon as it was introduced in the US, last fall.

The bivalent booster is currently recommended for all Americans age 5 and older, at least 2 months after the last dose of vaccine, or 3 months after infection with COVID-19.

In February, about 6 months after his previous booster dose, Osterholm asked if his protection could be boosted with another bivalent shot, but was refused.

Studies of the effectiveness of COVID-19 vaccines show that protection against infection, emergency room visits, and hospitalization wears off after six months.

Some protection is left in B cells and T cells, components of the immune system that retain memory of past invaders, although the duration of this protection is not fully understood.

Last week, Osterholm contracted COVID-19 for the first time.

“I have no idea how I got it,” he said. “I was wearing an N95 mask.”

He also knows that receiving another bivalent booster dose will not completely prevent infection. However, Osterholm wonders what his health would have been like if he had received it.

Protection may be diminished from bivalent enhancers

Bivalent vaccines include two types of instructions to help the body fight COVID-19.

The first shows how to identify the ancestral strain of “Covid-19”, which is no longer circulating. The second group helps to better identify and attack the Omicron virus and its progeny.

Data collected by the US Centers for Disease Control and Prevention shows that updating the vaccine enhances protection.

Immunized people are 14 times less likely to die than unvaccinated people, and three times less likely to die than vaccinated people who did not receive a bivalent booster dose.

Although the bivalent vaccines have been beneficial, the new data suggests that just like the boosters that came before them, they may be declining in their level of protection.

And in the first two months after adults get the booster, the dose appears to be 50% more effective at preventing hospital or emergency room visits due to COVID-19.

However, by four months, the incremental protection from bivalent vaccines drops to just over 30%, according to data presented at the February meeting of the Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices.

Waiting for spring boosters

Some people are eagerly awaiting opportunities to get another dose.

“This is the most common question I’m being asked right now,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University.

However, he does not see spring boosters on the horizon in the United States.

“One of the disappointments with mRNA vaccines is that they don’t hold up as well as we would like for reasons that I think we don’t fully understand,” said Dr. Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine, in Houston.

He hopes to see vaccine doses available for adults 50 and older, not the 65-and-over category being considered by the Food and Drug Administration.

“The doses are there, and if we don’t use them soon, we’ll have to get rid of them,” Hotez explained.

Others worry that giving more boosters to the elderly and immunocompromised might give them a false sense of security and little extra protection.

Dr. Yvonne Maldonado, professor of global health and infectious diseases at Stanford University, said that advancing age reduces the body’s ability to respond to vaccines. People with weakened immune function may not notice much improvement in protection after vaccination.

“In this case, I don’t know if the extra boosters would make a difference, because we know the immune response for a lot of people is not going to be great,” she added.

You may also like

Leave a Comment