Johnson & Johnson Single-Shot COVID-19 Vaccine Elicits Both Humoral and Cellular Response, Protects Against Delta Variant

The results indicated that T cell responses—including CD8+ T cells, which seek out and destroy infected cells—persisted over the 8-month timeframe of the study, according to the authors.

Both the antibody and T cell immune responses generated by the Johnson & Johnson single-shot COVID-19 vaccine were stable through 8 months following immunization, according to the interim results of a phase 1/2a sub-study published in the New England Journal of Medicine. The results indicated that T cell responses—including CD8+ T cells, which seek out and destroy infected cells—persisted over the 8-month timeframe of the study, according to the authors.

The ongoing phase 1/2a trial is a multi-center, randomized, double-blind, placebo-controlled study that aims to evaluate the safety, reactogenicity, and immunogenicity of the Janssen COVID-19 Vaccine. The vaccine is administered at 2 dose levels intramuscularly, either as a single dose or on a 2-dose schedule 8 weeks apart. The sub-study currently reporting results uses cohort 1b of the ongoing trial, which enrolled 25 adults who are 18-55 years of age.

Data from the study suggested that 1 dose of the Johnson & Johnson COVID-19 vaccine resulted in the maturation of B cell response without further booster shots. Mature B cells produce antibodies that help to fight SARS-CoV-2. In combination with the T cell responses, these dual mechanisms of protection were capable of protecting against COVID-19, including disease caused by notable variants such as the Delta, Alpha, Beta, Gamma, Epsilon, and Kappa variants. This indicates an expansion of neutralizing antibodies over the 8 months of the study, according to the authors.

“These peer-reviewed data provide further and deeper insights into the durable humoral and cellular immune responses elicited by the single-shot Johnson & Johnson COVID-19 vaccine, thus offering potentially a dual mechanism of protection against COVID-19 disease, including against the Delta variant and other variants of concern,” said Mathai Mammen, MD, PhD, global head of Janssen Research & Development, in a press release. “The study showed that variant-specific neutralizing antibodies increased over the eight months examined after vaccination which suggests the maturation of B-cell responses. In addition, the T-cell responses are especially strong and stable over time, which is also potentially important for activity against these variants.”

The data complimented results previously published in Nature providing evidence of the Johnson & Johnson vaccine’s ability to elicit a response from multiple components of the immune system in individuals. Further, preclinical data demonstrated efficacy against SARS-CoV-2 infection caused by the Beta variant in non-human primates.

Additional data from analyzing blood samples obtained from a subset of participants in the phase 3 ENSEMBLE study demonstrated that the single-shot vaccine resulted in neutralizing antibody activity against the Delta variant at higher levels than was previously observed for the Beta variant.

REFERENCE

Johnson & Johnson single-shot COVID-19 vaccine demonstrated a durable immune response and elicited dual mechanisms of protection against delta and Other SARS-CoV-2 variants of concern in data published in New England Journal of Medicine [news release]. Johnson & Johnson; July 14, 2021. Accessed July 22, 2021. https://www.jnj.com/johnson-johnson-single-shot-covid-19-vaccine-demonstrated-a-durable-immune-response-and-elicited-dual-mechanisms-of-protection-against-delta-and-other-sars-cov-2-variants-of-concern-in-data-published-in-new-england-journal-of-medicine