J&J COVID-19 Vaccine Shows a 90% Immune Response in Interim Data

After a single dose vaccination, Johnson & Johnson’s (J&J) JNJ-78436735 COVID-19 vaccine showed neutralizing antibodies against COVID-19 in over 90 percent of study participants at Day 29 and 100% of participants aged 18-55 years at Day 57.

These neutralizing antibodies remained stable through Day 71, currently the latest timepoint available in this ongoing study, in all participants aged 18-55 years.

The company plans to release data in participants 65 years and older in late January.

The findings were published in the New England Journal of Medicine.

The single dose investigational vaccine, which is being developed by the Janssen Pharmaceutical Companies of Johnson & Johnson, is more commonly referred to as the Ad26.COV2.S vaccine, and is a recombinant, replication-incompetent adenovirus serotype 26 (Ad26) vector encoding a full-length and stabilized SARS-CoV-2 spike (S) protein.

The phase 1/2a analysis showed that the company’s COVID-19 vaccine candidate was generally well-tolerated across all study participants.

While the vaccine is being studied as a single dose administration shot, the trial did evaluate 2 dose administration. The data showed that a second dose of JNJ-78436735, administered 56 days apart, was less reactogenic while it triggered more than a two-fold increase in antibodies against COVID-19.

“Although all ongoing phase 3 studies of other Covid-19 vaccines have assessed two-dose schedules, a single dose of Ad26.COV2.S elicited a strong humoral response in a majority of vaccine recipients, with the presence of S-binding and neutralizing antibodies in more than 90% of the participants, regardless of either age group or vaccine dose,” the investigators wrote.

The vaccine is built upon the company’s AdVac platform, which was used for its Ebola vaccine.

J&J said it believes it will be able to announce topline phase 3 data for its vaccine in late January 2021, and if it is shown to be safe and effective, the company expects to submit an application for Emergency Use Authorization (EUA) with the US Food and Drug Administration (FDA).

With this news, there has been speculation this could lead to the FDA setting a date for a Vaccines and Related Biologic Products Advisory Committee (VRBPAC) meeting in February to discuss whether or not they would grant the vaccine an EUA.