The U.S. Food and Drug Administration granted the Janssen COVID-19 vaccine emergency use authorization to be distributed and used for people ages 18 and above this past Saturday, Feb. 27. This comes the day after an independent advisory committee to the FDA voted to endorse the vaccine. 

“The FDA, through our open and transparent scientific review process, has now authorized three COVID-19 vaccines with the urgency called for during this pandemic, using the agency’s rigorous standards for safety, effectiveness and manufacturing quality needed to support emergency use authorization,” said acting FDA Commissioner Dr. Janet Woodcock. 

Janssen Pharmaceuticals, part of Johnson & Johnson, sent a EUA request to the FDA on Feb. 4 for the authorization of their adenovirus vaccine.

The FDA evaluated efficacy data from Johnson & Johnson’s ongoing ENSEMBLE phase 3 clinical trial with over 39,321 participants in the United States, South Africa and various Latin American countries including Argentina, Brazil, Chile, Colombia, Mexico and Peru. Some of these countries are sites of novel mutants of the SARS-Cov-2 virus. They tested for efficacy at two time-points — 14 and 28 days after the vaccine.

Overall, the vaccine offered 66% protection against moderate COVID-19 disease, 85% protection against severe COVID-19 disease and complete protection against hospitalization and death after 28 days. 

The study found that the vaccine was 72% effective at protection against moderate to severe COVID-19 infection in the United States, 66% in Latin America and 57% in South Africa at the 28-day point.

“What is concerning about COVID-19 is that it sends people to the hospital, some people die. The concern is about the severe disease. [The vaccine] is huge protection” said Dr. Dana Mazo, assistant professor of Infectious Diseases at Mount Sinai Hospital. She is also the lead investigator for COVID-19 clinical trials at Mount Sinai Queens. 

With another vaccine equipped in its arsenal, the United States can start to vaccinate even more people. The vaccine’s design also offers some additional advantages. For example, the vaccine requires only one dose. 

“Logistically it can be very hard for people to come back to get the second dose. With the same amount of supply [of the vaccine] we can vaccinate more people,” Mazo said.

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This vaccine is also simpler to transport and store. The vaccines can be stored for up to 3 months in a refrigerator and remain stable. The Moderna and Pfizer mRNA vaccines are less stable and require the vaccine to be stored at really cold temperatures.

“This is a vaccine that could be distributed and administered in a doctor’s office, or could be distributed and administered at a health fair because you only have one dose and it is much easier to store it and to transport it,” Mazo said.

This has implications for distribution by enabling the vaccine to be administered in more rural and harder-to-reach areas. 

The Johnson & Johnson adenovirus type 26 vaccine works differently from the mRNA vaccines produced by Moderna and Pfizer. In this vaccine, DNA encoding the spike protein on the surface of the COVID-19 is placed within an adenovirus. This virus has been altered to inhibit its ability to replicate.

Once within cells, the DNA inside the adenovirus can be used by human cells to manufacture the spike protein, according to Johnson & Johnson. This triggers our immune system to mount a response and create antibodies that will be ready to face off another attack.

This COVID-19 vaccine builds upon the technology of Janssen’s AdVac platform, which the company has used to develop vaccines against other diseases like Ebola and HIV. Health officials strongly urge that people take whichever vaccine is available to them. 

“When the vaccine gets by the FDA in an emergency authorization, take the vaccine,” said Dr. Anthony Fauci, chief medical advisor to President Joe Biden. “This is a race between the virus and getting vaccines in people.”

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