FDA Authorizes Janssen COVID-19 Vaccine in the US

February 27, 2021
Killian Meara

The VRBPAC voted 22-0 with no abstentions to support the benefit-risk profile associated with Ad26.COV2.S on Friday night.

The US Food and Drug Administration (FDA) has granted Emergency Use Authorization (EUA) to Ad26.COV2.S, becoming the third vaccine approved for the prevention of COVID-19 in the United States.

The decision was announced on Saturday, and follows in the footsteps of Pfizer and Moderna, who were both granted authorizations for their vaccines this past December.

The FDA issued the authorization to Janssen Pharmaceuticals, a company headquartered in New Jersey that is owned by Johnson & Johnson, based on data shared prior to the Vaccines and Related Biological Products Advisory Committee (VRBPAC) meeting on Friday.

The vaccine will be the first of its kind approved for the prevention of COVID-19 in the United States, as it requires only one-shot and contains a live virus, unlike Pfizer and Moderna’s mRNA technology.

The Vaccine

The Ad26.COV2.S is an intramuscular injection vaccine consisting of a replication-incompetent recombinant adenovirus type 26 (Ad26) vector which expresses the SARS-CoV-2 spike (S) protein. Additional inactive ingredients include citric acid monohydrate, trisodium citrate dihydrate, ethanol, 2-hydroxypropylβ-cyclodextrin (HBCD), polysorbate 80, sodium chloride, sodium hydroxide, and hydrochloric acid.

The vaccine was created using Janssen’s AdVac and PER.C6 technologies, which provide a manufacturing system that is both cost-effective and offers a quicker, high-yield and large-scale ability to produce vaccines. The same technologies have been used by the company to create vaccines for Ebola, as well as candidates for Zika, RSV and HIV.

The vector expressing the SARS-CoV-2 S protein is grown in a media which contains amino acids but no animal-derived proteins. It is then processed through several steps of purification after propagation, formulated with the inactive ingredients and placed into vials which are able to contain up to 5 doses.

The vaccine was developed by Janssen in collaboration with The Biomedical Advanced Research and Development Authority (BARDA), a US Department of Health and Human Services office which is responsible for the procurement and development of medical countermeasures. The company has also been working with the Beth Israel Deaconess Medical Center (BIDMC), who supported the development of the vaccine.

As of December 31st, 2020, Ad26-based vaccines have been administered to nearly 200,000 participants in both clinical studies and vaccination programs. The FDA has said that the vaccines have shown an acceptable clinical safety profile.

The Trial Data

Ad26.COV2.S is currently undergoing 5 randomized, double-blind, placebo-controlled clinical trials. Study 3001, a phase 3 efficacy, safety and immunogenicity study with a single-dose regimen, was the primary focus of the EUA review. The study included 40,000 participants who were randomized 1:1 to receive intramuscular injection of either vaccine or a placebo.

Participants between the ages of 18 to 40 were limited to 20% of the total study population and at least 30% was aged ≥60 years, so that observations could be made on older populations who are more at risk.

At the primary efficacy analysis, Ad26.COV2.S was found to be 66.9% effective at preventing protocol-defined moderate to severe/critical COVID-19 occurring at least 14 days after vaccination, and 66.1% effective at least 28 days after vaccination in participants without a previous SARS-CoV-2 infection.

The vaccine also showed a 76.7% efficacy on the secondary endpoint of efficacy against protocol-defined symptomatic COVID-19 of any severity with onset at least 14 days after administration and 85.4% with onset at least 28 days after.

Furthermore, among the international study population of which 40.6% were from Latin America and 12.7% were from South Africa, Ad26.COV2.S showed an efficacy of 64.7% and 61%, and 52% and 64%, respectively.

In the video below, Jeremy Kamil, PhD, an associate professor in the department of microbiology and immunology at Louisiana State University Health Shreveport, discussed with Contagion how Ad26.COV2.S is effective against novel variants like the one found in South Africa.

“There’s plenty of evidence that even the Johnson & Johnson vaccine…was effective in South Africa against the new variants…It 100% prevented deaths. It was a little bit less good at preventing infections…but I think it had a magnificent effect on hospitalization and death.”

Efficacy estimates across all demographic subgroups in supportive analyses of both endpoints were consistent with the overall study population.

Among the participants who were eligible for safety analysis, investigators observed no specific safety concerns that would warrant assessment prior to an EUA.

The Distribution

Janssen has announced that upon approval, the company plans to immediately start distributing the vaccine to the US government. They also stated that they expect to supply 100 million doses to the country in the first half of 2021.

The vaccine is compatible with current distribution channels and is able to remain stable for up to 2 years at -20 degrees Celsius or for at least 3 months at temperatures between 2 and 8 degrees Celsius in most standard refrigerators.

The company will ship the doses of the vaccine with the same cold chain technologies that it uses to transport their other products.

Additionally, in collaboration with GAVI, The Vaccine Alliance and COVID-19 Vaccines Global Access (COVAX), Janssen expects to enter into an Advanced Purchase Agreement (APA) that would enable them to provide up to 500 million doses of the vaccine to COVAX through 2022.

What’s Next

Though the amount of doses that will be immediately available remains unclear, the issuance of the EUA to Janssen comes at a time when COVID-19 cases have been steadily dropping across the entire US.

However, the numbers still remain staggeringly high, and experts have consistently stressed the fact that it is no time to let up on safety measures and that pushing forward with the vaccine plan is of vital importance. Having more doses to give out, especially if it only requires a single shot, will help significantly in the battle against the disease.

While the vaccine was deemed safe, there is still insufficient data in some subpopulations including children less than 18 years of age, pregnant and lactating women, infants and immunocompromised patients. Also, as with all novel vaccines, the use in a larger number of individuals may potentially reveal less frequent and/or more serious adverse events that were not detected in the trials.

“Johnson & Johnson embarked on the global effort to combat the COVID-19 pandemic a year ago, and has brought the full force of our capabilities, as well as tremendous public-private partnerships, to enable the development of a single-shot vaccine. Our goal all along has been to create a simple, effective solution for the largest number of people possible, and to have maximum impact to help end the pandemic,” Alex Gorsky, Chairman, Board of Directors and Chief Executive Officer at Johnson & Johnson said in a statement. “We’re proud to have reached this critical milestone and our commitment to address this global health crisis continues with urgency for everyone, everywhere.”