Johnson & Johnson Says Single-Dose COVID-19 Vaccine Will Be A 'Game-Changer'

Johnson & Johnson has released the results of its phase three COVID-19 vaccine trial and plans to seek emergency use authorization by the Food and Drug Administration.

Results demonstrated 85% protection against severe coronavirus disease in adults of all ages and racial groups 28 days after vaccination. The overall effectiveness rate for preventing moderate to severe illness was 72% in the U.S. and 66% across all countries studied, the pharmaceutical giant said. 

Benefits include that it only requires one dose — as opposed to Moderna and Pfizer's two-dose inoculations — and that it can be stored in a regular refrigerator. 

"There's no question that this vaccine is going to be a game-changer," Dr. Mathai Mammen, global head of pharmaceutical research and development for Johnson & Johnson, told CBS News' Dr. Tara Narula. "The real-world effectiveness of this vaccine is apt to be very high."

The Phase 3 clinical trials included about 44,000 participants in the U.S., Latin America and South Africa. In all, 468 people contracted COVID-19 in the study, which looked at protection against both moderate and severe cases. No one who got the vaccine died of the disease.

"What we mean by severe COVID is feeling particularly sick at home. That's about 80% of the severe cases. Or in some cases, being sick enough to go seek medical attention," Mammen explained.

Results also showed protection against multiple emerging virus variants, including the strain recently discovered in South Africa — which has also been detected in the U.S. 

Mammen said the numbers were encouraging. 

"We had 85% efficacy against serious COVID disease. And that's meaningful because there's a variant in South Africa that's particularly problematic. So that makes me rest easier," he said.

The Pfizer and Moderna vaccines use mRNA to carry the code to make the coronavirus spike protein, which allows the virus to invade human cells. The Johnson & Johnson vaccine uses DNA and a modified, weakened version of a cold virus to gain entry into human cells. It then triggers an immune response and teaches the body to fight off the real coronavirus. 

Asked why Johnson & Johnson's vaccine only needed one dose, Mammen explained they "went through an experimental process and picked the very best one that optimized for neutralizing antibodies, binding antibodies and T-cells."

"So we're able to get a lot more immune response than a typical single shot," he said.

Bali Pulendran, an immunologist at Stanford Medicine, believes a single-dose vaccine can only aid the Biden administration's plan to increase availability. 

'I would much prefer only to have to go in to get my one shot rather than to have to go in a month or three weeks later to get my second shot," he said.

Pulendran said a prospective single-dose vaccine would have an "enormous public health impact."

"From a clinician's perspective, it's so much easier to administer a single dose vaccine," he said,

The U.S. government has preordered about 100 million doses, but Johnson & Johnson only expects to have fewer than 10 million doses available for February.

CBS News asked Dr. Mammen about reports of production delays. He said the company will meet the U.S. order by June, and make a billion doses this year globally. 

Johnson & Johnson's data still needs to undergo review by the FDA.

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