Johnson & Johnson COVID vaccine recommended for emergency use. How is it different?

Katie Camero
·4 min read

Another coronavirus vaccine is one step closer to joining the fight against the pandemic in the U.S. — and this one only requires a single shot.

A U.S. Food and Drug Administration advisory committee of medical experts on Friday recommended the Johnson & Johnson coronavirus vaccine for emergency use authorization after reviewing and discussing the latest clinical trial data, deciding that the benefits outweigh the risks.

It’s the third COVID-19 vaccine to be recommended for emergency use authorization in the United States, and could be the third to be fully authorized for use in people 18 and older if the FDA gives it the green light. That final decision could come as soon as this weekend.

The Friday vote comes after South Africa became the first country to start using the Johnson & Johnson vaccine on Feb. 17.

Unlike the authorized Pfizer-BioNTech and Moderna vaccines that require two doses separated by about a month, the Johnson & Johnson shot requires only one dose. It also can be stored for three months at normal temperatures, easing distribution efforts and accelerating vaccination rates compared to the currently available vaccines that require ultra cold refrigeration.

An FDA “authorization” is not the same as an “approval.” The emergency use authorizations granted to Pfizer and Moderna allow the use of their still “unapproved” vaccines in emergency situations, such as a pandemic, for which “there are no adequate, approved and available alternatives.”

All products with an emergency authorization are required to be proven safe during clinical trials.

How does the Johnson & Johnson COVID-19 vaccine work?

The Johnson & Johnson shot is a viral vector vaccine.

It works by delivering a harmless DNA virus called an adenovirus that has been genetically modified so it cannot make copies of itself in humans or cause disease — like a box that contains a user-friendly handbook on anything and everything coronavirus.

These types of viruses, when not manipulated by scientists, cause the common cold, “so they’re good for transporting things into humans,” the company said.

This modified virus carries specific instructions into our cells that teach them how to make the spike protein the novel coronavirus uses to infect people, according to the Centers for Disease Control and Prevention.

Side effects after your second dose of COVID vaccine may be more intense. Here’s why

Our cells then display the spike proteins on their surfaces like a trophy on a pedestal, which the immune system doesn’t recognize. This triggers the production of coronavirus-fighting antibodies and primes the body to protect itself against the pathogen if it comes into contact with it.

This method is different from how the Pfizer and Moderna shots work. Instead of DNA, they insert mRNA — a molecule already found in the body — which stores directions that teach our cells to make copies of the coronavirus spike protein, sparking the creation of antibodies without the assistance of a separate harmless virus.

Viral vector vaccines cannot infect someone with the coronavirus or with the modified adenovirus. They also do not affect or interact with our DNA in any way.

How effective is Johnson & Johnson vaccine at preventing COVID-19?

The Phase 3 clinical trial, which included nearly 44,000 participants 18 years and older, found that the Johnson & Johnson vaccine was overall 66% effective at preventing moderate to severe COVID-19 in the lab as early as 14 days after getting jabbed.

In the U.S., the vaccine was about 72% effective at preventing moderate to severe COVID-19. However, that percentage dropped to 64% in South Africa, where a more contagious coronavirus variant has dominated all others. Still, the vaccine offered “similarly high” protection in both regions, including Brazil, where another more transmissible variant has emerged.

Both the Pfizer and Moderna vaccines have efficacy rates of about 95%.

There were no deaths among those who received the vaccine; seven people who got a placebo died from COVID-19.

Johnson & Johnson had said it plans to ship vaccines “immediately upon emergency use authorization, and deliver enough single-doses by the end of March to enable the vaccination of more than 20 million Americans.”

The company submitted a request for emergency use authorization on Feb. 4.

Side effects of the Johnson & Johnson COVID-19 vaccine

Immediate reactions to the shot 30 minutes post vaccination were “infrequent,” occurring in 0.02% of participants, while there were no reports of anaphylaxis, or severe allergic reactions, immediately after getting jabbed.

The most common side effects were pain around the injection site (49%), headache (39%), fatigue (38%) and muscle aches (33%) — similar reactions but slightly less frequent than those from the Pfizer and Moderna shots. They were less common in adults older than 60 and generally resolved one to two days after vaccination.

Skin rashes, blood clots and tinnitus were reported in five, 15 and six vaccine recipients, respectively, within seven days after getting the shot. The company said these events are “possibly related to the vaccine,” but “data at this time are insufficient to determine a causal relationship between these events and the vaccine.”

There were “no specific safety concerns” among groups by age, race, ethnicity, medical comorbidities or prior coronavirus infection, according to the report.

Participants who were pregnant or were planning on becoming pregnant within three months of getting the vaccine were excluded from the study. Four individuals reported they became pregnant after receiving the shot; the company said it is collecting data on them.