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Study: J&J Vaccine 66% Effective Against COVID-19

coronavirus vaccine

Jan. 29, 2021 -- The Johnson & Johnson/Janssen single-dose coronavirus vaccine is 66% effective in preventing infection globally and 72% effective in the United States, according to the highly anticipated, interim phase III results announced this morning.

The 44,000-participant study was conducted in the U.S., South America and South Africa.

While those results are lower than the 94% to 95% effectiveness of the existing Moderna and Pfizer vaccines, the Johnson & Johnson results are reasons for optimism, officials from the National Institutes of Health told reporters.

Specifically, they said the fact that the clinical trials showed the Johnson & Johnson vaccine was 85% effective in preventing severe cases of COVID was very important.

Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, said the focus should not just be on the overall numbers. "The most important thing from a public health standpoint domestically is to keep people out of the hospital and prevent them from getting severe illness," he said.

"More important than preventing someone from getting some aches and a sore throat is to prevent people -- particularly people who have underlying conditions and the elderly, the ones most susceptible to a severe outcome – [from getting] severe disease," He said.

Prevention of severe outcomes in a high percentage of individuals "will alleviate so much of the stress, human suffering and death."

Fauci acknowledged that many people will naturally focus on the distinction among the vaccines’ different rate of effectiveness.

"This could be a messaging challenge … [but] you have to make sure people understand the implications,” he said.

It is more complex, he added, than just asking people: "If you go to the door on the left, you get 94% or 95%. If you go to the door to the right, you get 72%. What door do you want to go to?"

Instead, the messaging should be that "this and the other vaccines we have actually preventing severe disease to a very substantial degree."

Janssen said it is not a fair comparison.

"The vaccine programs that went a couple of months ago, they ran their studies during different times, when the pandemic was less complex. There were not these variants and there was not the same level of incidence, which puts pressure on vaccine efficacy," said Mathai Mammen, global head of research and development for Janssen.

"So the numbers cannot really be compared, and that does pose a messaging challenge," he said. "But the reality is if one was to run the same studies [for the Pfizer and Moderna vaccines] today you would likely see different results."

Asked if the efficacy figures could affect vaccine hesitancy, NIH Director Francis Collins, MD, said most reluctance among people to get vaccinated against SARS-CoV-2 stems from concerns about safety. "The safety record is extremely good for this vaccine, as it is for the others who have received emergency use authorization."

Johnson & Johnson plans to submit for emergency use authorization from the FDA next week, at which point the company plans to release more information of side effects and deaths.

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