J&J vaccine as booster dose of Pfizer would elevate immune response

CDC Approved Booster Dose Keys 1:28

(CNN) -

Using Johnson & Johnson's Covid-19 Vaccine as a Booster Dose for People Initially Immunized with the Pfizer / BioNTech Vaccine Produces a Strong Immune Response and May Do More to Protect Against Serious Diseases researchers reported Sunday.

Their small study of 65 volunteers who initially received two doses of the Pfizer / BioNTech vaccine showed that using the J&J Janssen vaccine as a booster dose produced a slower but more sustained antibody response against the parent strain of the virus, as well as against the delta and beta variants, they said.

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What the booster dose did

The Pfizer / BioNTech booster dose produced a faster and stronger immune response that waned faster, their study suggested.

"Both vaccines increase antibody titers very well. By week four, the neutralizing antibody levels were comparable," Dr. Dan Barouch of Beth Israel Deaconess Medical Center and Harvard Medical School, who led the study, told CNN. study team.

But after four weeks, antibody levels began to decline in people who received booster doses of Pfizer, while they continued to rise in people who received the J&J vaccine.

The J&J vaccine also increased the number of immune cells called CD8 T cells.

Antibodies are a first line of immune protection that can prevent a virus from infecting cells, while T cells appear later and destroy infected cells.

This defense of T cells does not prevent mild infections, but it can prevent them from progressing to serious disease.

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What about the omicron variant?

While the study did not include the omicron variant, Barouch said the findings may be important in finding ways to combat the latest variant.

"For variants like omicron that could partially evade antibody responses, CD8 T cell responses may be particularly relevant for protection," he said.

"We think they are relevant in general, but they can become particularly relevant if a variant emerges that can largely escape antibodies."

"We don't know for sure about omicron yet, but as I'm sure you know, there has been a lot of concern or speculation that it could result in at least some degree, maybe a substantial degree, of vaccine-induced antibody escape. For a booster dose, a booster is necessary to increase antibody and T-cell responses. "

Barouch said his team has submitted the findings to a peer-reviewed journal, and in the meantime, they have been published online, without peer review, on the MedRxiv preprint server.

covid-19 vaccine