Johnson & Johnson vaccine shows protection in pre-clinical trials

An experimental novel coronavirus (COVID-19) vaccine developed by Johnson & Johnson protected against infection with SARS-CoV-2, the virus that causes COVID-19, in pre-clinical studies, according to new data published in the journal Nature.

In the studies, researchers first immunized the NHPs with a panel of vaccine prototypes, and then challenged them with SARS-CoV-2 infection. The scientists found that, of seven vaccine prototypes tested in the study, Ad26.COV2.S, elicited the highest levels of neutralizing antibodies to SARS-CoV-2.

The level of antibodies correlated with the level of protection, confirming previous observations, and suggesting they could be a potential biomarker for vaccine-mediated protection. The six NHPs that received a single immunization with Ad26.COV2.S showed no detectable virus in the lower respiratory tract after exposure to SARS-CoV-2, and only one of six showed very low levels of the virus in a nasal swab at two time points.

The investigational vaccine elicited a robust immune response as demonstrated by “neutralizing antibodies,” successfully preventing subsequent infection and providing complete or near-complete protection in the lungs from the virus in non-human primates in the pre-clinical study.

The clinical trial program, including the Phase 1/2a clinical trial and the phase 3 clinical trial program, will evaluate both one- and two-dose regimens of Ad26.COV2.S in parallel studies. The phase 1/2a trial will evaluate the safety, reactogenicity with expected reactions to vaccination, such as swelling or soreness, and immunogenicity of Ad26.COV2.S in over 1,000 healthy adults aged 18 to 55 years old, as well as adults aged 65 years and older. Planning also is underway for a phase 2a study in the Netherlands, Spain, and Germany and a phase 1 study in Japan. 

As the company plans its COVID-19 phase 3 clinical development program, discussions are underway with partners with the objective to start a pivotal phase 3 clinical trial of the single vaccine dose versus placebo in September, pending the interim data of the phase 1 and 2 trials and approval of regulators. Simultaneously, the company also is planning to start a parallel phase 3 clinical trial of a two-dose regimen versus placebo.

The pre-clinical studies were conducted by researchers from Beth Israel Deaconess Medical Center (BIDMC) in collaboration with the Janssen Pharmaceutical Companies of Johnson & Johnson and others as part of its ongoing collaboration to accelerate the development of a SARS-CoV-2 vaccine.

A phase 1/2a first-in-human clinical trial of the vaccine candidate, Ad26.COV2.S, in healthy volunteers, has now commenced in the United States and Belgium.

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