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J&J says single dose of coronavirus vaccine 66% effective in large trial

A single shot of a coronavirus vaccine developed by Johnson & Johnson protected volunteers enrolled in a sprawling, multi-country study from developing COVID-19, results disclosed by the company Friday showed.

The finding is a boost to a sputtering global immunization drive, adding another effective vaccine to a mix of shots already cleared for use in dozens of nations. J&J, one of the world’s largest drugmakers, expects it can produce 1 billion doses of its vaccine this year.

But the results indicate vaccination was only 66% effective in preventing moderate or severe COVID-19 compared to a saline injection used as placebo. Expectations were for a higher number, particularly after shots developed by Pfizer and Moderna were found to be more than 90% effective at preventing symptomatic COVID-19.

In the U.S., the observed efficacy was stronger, at 72%. But in Latin America and in South Africa, where new, more infectious variants are circulating, protection from the vaccine appeared less robust, at 66% and 57% effective, respectively.

On a call Friday, Mathai Mammen, head of R&D at J&J’s Janssen unit, argued the results for his company’s vaccine should not be compared to numbers generated in earlier studies done before the variants were prevalent.

“You really cannot compare our 72% [rate] in the U.S to a 94% [rate] done at a different time,” he said.

J&J’s data come one day after Novavax reported results from two studies of its vaccine that also showed diminished efficacy against the coronavirus variant first detected in South Africa. Taken together, the two data sets signal the urgency behind rapidly vaccinating large portions of the world’s population.

Even with lower efficacy, though, J&J’s vaccine could still play an important role, as Friday’s data show one dose can be protective. Pfizer’s, Moderna’s and Novavax’s vaccines are given via two doses, as are most others now authorized or in late-stage testing.

J&J’s vaccine can also be shipped and stored at refrigerator temperatures, rather than the ultra-cold temperatures required for Pfizer’s and Moderna’s.

An independent committee overseeing J&J’s trial estimated the vaccine’s efficacy after 468 participants in the company’s trial got either moderate or severe COVID-19. Study investigators calculated efficacy against just severe disease as 85%, and J&J noted protection increased over time.

“Success against severe illness is by far the most important feature from a public health standpoint for a COVID-19 vaccine,” said J&J’s Mammen.

No vaccinated participant in the study required hospitalization or intensive care starting 28 days after receiving their shot. There were no deaths related to COVID-19 in the vaccine group, compared to 5 in the placebo group.

J&J said it will soon ask the Food and Drug Administration to clear its vaccine for emergency use in the U.S. The agency would then begin the painstaking work of reviewing and corroborating J&J’s data, as well as convene an advisory committee to independently assess the results.

Prior meetings to review Pfizer’s and Moderna’s results were largely positive, despite some wrangling over authorization language. The more modest efficacy of J&J’s shot, by comparison, could present thornier questions for the committee to consider, as will the effect of new variants on protection.

The FDA authorized both Pfizer’s and Moderna’s shots about a month after announcement of initial data.

U.S. government officials have previously said they hoped J&J’s vaccine could win authorization in February, although Paul Stoffels, the company’s chief scientific officer, said in a mid-January interview with Bloomberg that an FDA decision may not come until March.

Through “Operation Warp Speed,” the U.S. pre-ordered 100 million doses of J&J’s vaccines at a price of $10 each. Per the August 2020 contract, 12 million doses are due to be delivered by the end of February — critical reinforcements for an immunization effort that’s already short on supply and struggling with other roll-out hurdles.

But production may have already hit a snag. In mid-January, The New York Times reported J&J has fallen two months behind schedule, putting its supply schedule in jeopardy.

On Thursday’s call, J&J executives emphasized the company would meet its supply commitments. A recent report prepared by the U.S. Government Accountability Office, however, noted J&J expects to only have 2 million doses ready for delivery upon FDA authorization.

J&J has contracted with Somerset, New Jersey-based Catalent and Baltimore, Maryland-headquartered Emergent Biosolutions to manufacture the shot. It’s also producing doses at its own plant in Leiden, Netherlands.

J&J’s vaccine uses a different technology than Pfizer’s and Moderna’s. Genetic instructions for the coronavirus’ telltale spike protein are written into the genome of a harmless virus known as adenovirus type 26. Once injected, the re-engineered virus enters cells and instructs them to produce the spike protein, thereby teaching the body’s immune system to recognize and resist infection. (J&J uses the same technology for its Ebola vaccine, which was approved in Europe last year.)