Johnson & Johnson says booster dose increased COVID antibodies in early trials

CHICAGO – A booster dose of Johnson & Johnson’s COVID-19 vaccine sharply increased antibody levels against the coronavirus, according to preliminary data from two small, early-stage trials, the company said in a press release on Wednesday .

J&J has come under pressure to prove whether a booster would increase protection against its unique vaccine as the U.S. government prepares to launch a booster campaign next month. The company plans to discuss the data with U.S. regulators when designing its recall schemes.

Preliminary data announced on Wednesday involved a total of 17 people. It found that a second dose of the J&J vaccine delivered six months after the first resulted in a nine-fold increase in binding antibody levels from those seen 28 days after the first dose, the company said.

The company has not released data indicating whether a second dose of its vaccine increases levels of neutralizing antibodies, which prevent the virus from entering cells.

This data is still being analyzed, said Dr Dan Barouch, a vaccine researcher at Harvard who helped design J & J’s COVID-19 vaccine, but was not involved in the booster study. by J&J.

Unlike neutralizing antibodies, binding antibodies mark the virus for destruction by other parts of the immune system. Barouch said that the increase in binding antibodies generally correlates with the increase in neutralizing antibodies.

Several countries, including the United States, have started offering booster doses to vulnerable people, including those who are immunocompromised, as the delta variant has spread and some vaccinated people have been infected with SARS-CoV-2, the virus that causes COVID-19. But these campaigns have ruled out the J&J vaccine because there is no evidence that a booster helps increase vaccine protection.

Counselors from the United States Centers for Disease Control and Prevention, in particular, were awaiting information on how to counsel immunocompromised people who have received the J&J vaccine and who are already recommended for a booster.

According to J&J, studies published Wednesday showed significant increases in binding antibody responses in participants aged 18 to 55 and in those 65 and older who received a lower booster dose.

Study abstracts are submitted to the MedRxiv preprint server prior to peer review or journal publication.

The results were published ahead of the long-awaited results of J&J’s large two-dose vaccine trial. A spokesperson said those results will be available in the coming weeks.

In July, J&J published interim Phase 1 / 2a data in the New England Journal of Medicine that showed neutralizing antibodies generated by its vaccine remained stable eight months after immunization with a single dose.

“With this new data, we also see that a booster dose of the Johnson & Johnson COVID-19 vaccine further increases antibody responses in study participants who had previously received our vaccine,” Mathai Mammen, head of research and development at J & J’s Janssen pharma division, said in a statement.

“We look forward to discussing with public health officials a potential strategy for our Johnson & Johnson COVID-19 vaccine, increasing eight months or more after primary single-dose vaccination.”

Several scientists have expressed concerns that people who have received the J&J vaccine may need boosters. A study by a team at New York University found that a “significant fraction” of blood samples from recipients who received the J&J vaccine had weak neutralizing antibodies against Delta and several other coronavirus variants.

J&J said the company is working with the CDC, the US Food and Drug Administration, the European Medicines Agency, the World Health Organization and other health authorities to administer a booster with the Johnson vaccine. Johnson COVID-19.

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