- A mix-and-match Covid-19 booster vaccine policy would provide two distinct advantages
- t’s safe to mix vaccine types.
- Messy messaging around boosters Right now, the permission for boosters is complicated.
A mix-and-match Covid-19 booster vaccine policy would provide two distinct advantages: a stronger immune response to the extra shot, plus a lot less confusion for people seeking booster doses, reports CNN Health.
Customized Booster Vaccine
Early results from research being done by a National Institutes of Health-led team shows that giving people a different type of booster shot from their original vaccine type provided a stronger immune response than giving an extra dose of the same vaccine — findings in line with research done earlier in the year in Britain.
It’s no surprise to vaccine experts that it’s safe to mix vaccine types.
People do that regularly with a variety of vaccines, including influenza vaccines, which are made by six or seven different companies in the United States alone in any given year, following a variety of formulas.
In many countries, children are given polio vaccines first as a shot and then boosted with a different, oral formulation — a combination that’s both safer and more effective.
Immune response might broaden
Johnson & Johnson’s Janssen vaccine uses a different method: a genetically engineered common cold virus called an adenovirus that cannot itself replicate, but that can deliver a small piece of coronavirus to cells and also stimulate an immune response.
AstraZeneca’s vaccine uses technology similar to Johnson & Johnson’s, and several studies have shown alternating doses of this vaccine with Pfizer’s generates a strong immune response.
Broader immune responses “Mixing different vaccine types might broaden the type of immune response,” said Dr. Angela Branche, an assistant professor at the University of Rochester School of Medicine who is helping run some of the clinical trials mixing booster doses.
The mRNA vaccines stimulate powerful surges of antibodies.
“I think the data will show that boosting is certainly likely to be very effective in conferring additional and longer protection,” she told CNN.
Neutralizing antibodies increases response
While Lyke stressed that the data was incomplete, she did say it showed boosting with a different type of vaccine from the original dose provided a stronger antibody response than did boost with the same type.
“What I would note is that the neutralizing antibodies did increase in response to any boost of the primary vaccination series,” she told the FDA’s Vaccines and Related Biological Products Advisory Committee.
Messy messaging around boosters Right now, the permission for boosters is complicated.
Moderna and Johnson & Johnson have asked permission for boosters, too.
“This is going to be very, very messy in terms of the messaging.”
Anyone over 40 eligible to get boosters
Dr. Amanda Cohn, an official at the US Centers for Disease Control and Prevention who sits both on VRBPAC and on the CDC’s vaccine advisory committee, said it would be very helpful if there could be flexibility for people trying to deliver boosters — for instance, for drug retailers going into nursing homes with only one brand of vaccine.
Dr. Peter Marks, who heads the FDA’s vaccine arm, the Center for Biologics Evaluation and Research, dropped some heavy hints about the direction the agency might take.
“I think we got what we needed from this discussion,” he said.
He noted that several members of VRBPAC said they would feel comfortable with allowing anyone over 40 to get boosters.
The risk of complications from an inflammatory heart condition called myocarditis falls off considerably after age 40, he said.
That points to the possibility of FDA emergency use authorizations for boosters covering all three vaccines.
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Source: CNN Health
