FDA to authorize a Covid-19 vaccine that is at least 50% effective

FDA to authorize a Covid-19 vaccine that is at least 50% effective
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The Food and Drug Administration (FDA) says it would only authorize a Covid-19 vaccine that is safe and at least 50% effective.

“We all want a vaccine tomorrow. That’s unrealistic. And we all want a vaccine that’s 100% effective. Again, unrealistic,” said Dr. Stephen Hahn, the agency’s commissioner, during an interview with Dr. Howard Bauchner of the Journal of the American Medical Association.

“But we said 50%, and the reason was because we felt that that was a reasonable floor given the pandemic,” Hahn said.

He explained that requiring the minimum of 50% effectiveness for any Covid-19 vaccine provided guidance for manufacturers on designing their clinical trials.

The vaccine candidates from Moderna and Pfizer have entered their phase three trials earlier this week. The companies aim to register about 30,000 participants to prove the safety and effectiveness of the coronavirus vaccines in a large population.


Hahn hopes that the Covid-19 vaccine or vaccines that would be authorized will be proven more than 50% effective. However, there is a possibility that the US come up with a vaccine that, on average, lessens a person’s risk of an infection by only 50%.

“We really felt strongly that that had to be the floor,” he said, adding that it’s “been batted around among medical groups.” “But for the most part, I think, infectious disease experts have agreed that that’s a reasonable floor, of course hoping that the actual effectiveness will be higher.”

Dr. Fauci’s take

Meanwhile, White House health advisor Dr. Anthony Fauci also expressed his hope that the Covid-19 vaccine will prove an efficacy rate of at least 60%. This means that, on average, the vaccine would reduce one’s risk of the coronavirus infection by 60%.

“Obviously, we would like to see it much, much higher. But 60% is the standard that you do for the cutoff. That’s not unusual,” he said Monday. “I would like to see the highest percentage that we could possibly get.”

Hahn noted that the FDA will not authorize a vaccine that is not safe, regardless of how effective it seems to be.

“If we get to 50% but it’s not safe, to me, it’s not a vaccine that we can authorize,” he said. “We’re going to be very, very, very carefully looking at those safety data and we’re going to be transparent, Howard, about what we’ve seen.”

He also explained the FDA is employing new strategies and technology to properly manage data collection from clinical trial respondents in order to process data collection quickly on safety. The FDA will also oversee the safety of the vaccines once they get authorization and given to the public.

“We cannot have a situation where people lose trust in the FDA and in the clinical trial process,” he said. “That would be a mistake for all of us.”

Vaccine distribution

Microsoft founder Bill Gates said the coronavirus vaccine should not go to “the highest bidder” and instead must be distributed to the people who need them.

“If we just let drugs and vaccines go to the highest bidder, instead of to the people and the places where they are most needed, we’ll have a longer, more unjust deadlier pandemic,” Gates told the audience of an online Covid-19 conference held by the International AIDS Society.

“We need leaders to make these hard decisions about distributing based on equity, not just on market-driven factors,” he added.

The World Health Organization announced that 21 candidate vaccines are currently undergoing human clinical trials. Three of these vaccines have already entered the third phase of those trials.