J&J vaccine effective against Covid, though weaker against South Africa variant

A single shot of Johnson & Johnson’s Covid-19 vaccine is effective in preventing moderate to severe illness, the company reported on Friday.

Johnson & Johnson, who made the vaccine in partnership with Janssen Pharmaceuticals, is ready to ask the Food and Drug Administration for an emergency approval as early as next week.

Full coverage of the coronavirus outbreak

The regulator could approve the vaccine by the end of February. It would be the third Covid-19 vaccine available in the US, alongside Pfizer-BioNTech and Moderna.

The results of the Johnson & Johnson Phase 3 study found that the overall vaccine was 85 percent effective in preventing serious illnesses, including illnesses that require hospitalization. The data came from more than 44,000 participants in the United States, South Africa and several Latin American countries.

However, the results differed from region to region. In the US, the single dose was 72 percent effective in preventing both moderate and severe illness. (Moderate illnesses included symptoms such as low oxygen levels, shortness of breath, or deep vein thrombosis.) In Latin America, the effectiveness was lower at 66 percent. And in South Africa, where a worrying variety is the predominant strain, effectiveness dropped to 57 percent.

“Not a single person who was vaccinated and was sick after four weeks ended up in the hospital,” said Dr. Mathai Mammen, Johnson & Johnson’s global director of pharmaceutical research and development, told NBC News. This “makes me believe that this vaccine will stop this pandemic.”

No major side effects of the vaccine have been reported, including severe allergic reactions such as anaphylaxis, Mammen said.

“This study showed excellent efficacy against serious illness, hospitalization and death,” said Dr. Greg Poland, director of the vaccine research group at Mayo Clinic in Rochester, Minnesota. Poland was not involved in Johnson & Johnson’s vaccine trials.

Still, the lower effectiveness of the vaccine against the South African variant is worrying. The strain appears to pose a greater threat to current Covid-19 vaccines than other variants, such as the British variant.

Moderna said this week that its vaccine against the South African variant appears to be less effective, and a Pfizer study also suggested a less robust response. Biotech company Novavax said Thursday that initial results of its trials in South Africa also showed lower efficacy against the strain.

The South African variant was confirmed Thursday in South Carolina in two unrelated patients with no international travel history.

“With one of the more worrisome varieties on the planet, we were still able to show that we could prevent mostly moderate to severe infections,” said Dr. Buddy Creech, an infectious disease expert and an expert lead researcher in one of Johnson & Johnson’s Covid-19 vaccine studies at Vanderbilt University Medical Center in Nashville.

Download the NBC News App for full coverage of the coronavirus outbreakk

Overall, people with underlying health conditions like type 2 diabetes and high blood pressure are at higher risk of serious Covid-19 complications.

“To be able to take on this high-risk group and see that none of them ended up in the hospital after they got Covid – that’s impressive,” Creech said.

Overall, the results from Johnson & Johnson are not as strong as those from Pfizer and Moderna, which each had exceptionally high levels of effectiveness. These vaccines have been shown to be about 95 percent effective against symptomatic Covid-19 when given in two shots about a month apart.

“Whenever we know we’re going to see results from our clinical trials, we hold our breath,” said Creech. “If you told me nine months ago that we’d have a vaccine that was over 60 percent effective, I would have thought, my goodness, that’s better than influenza for most years.” In fact, the flu shot given during the 2019-2020 flu season was only 45 percent effective.

Unlike the Pfizer and Moderna vaccines, which require two doses about a month apart, the Johnson & Johnson vaccine can be administered entirely in one dose and requires only basic refrigeration for storage. The Pfizer and Moderna vaccines both work with messenger RNA, or mRNA, to teach the immune system how to recognize and fight the coronavirus. Johnson & Johnson’s vaccine takes a different approach and uses an inactivated adenovirus, a type of virus that causes colds, to transport these instructions into the body.

Johnson & Johnson is also investigating whether adding a second dose would further increase effectiveness. These results are not yet available.

If Johnson & Johnson is approved for the emergency, Johnson & Johnson expects to ship 100 million doses to the US by 2021.

“Our manufacturing schedule will allow us to meet our 2021 delivery commitments, including those signed with governments and global organizations,” a company spokesman said in a statement.

Follow NBC HEALTH on Twitter & Facebook.

Leave a Comment