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FDA chief says Covid-19 vaccine may get green signal before phase 3 trials are complete, here's what it means

However, scientists have warned against any such approval without reliable safety and efficacy data

The chief of the US Food and Drug Administration (FDA) said that he is willing to fast-track a Covid-19 vaccine by granting emergency use authorization (EUA) before the normal phase three clinical trials are complete if the agency found it "appropriate" to do so. Dr Stephen Hahn, the agency’s commissioner, however, insisted that he will not do so under political pressure and instead the decision will be based on science, as long as officials are convinced that the "benefits outweigh the risks".  

"It is up to the sponsor (vaccine developer) to apply for authorization or approval, and we make an adjudication of their application. If they do that before the end of phase three, we may find that appropriate. We may find that inappropriate, we will make a determination," said Hahn in an interview with the Financial Times. 

The head of FDA explained that an emergency use authorization by the FDA is not the same as a full approval. He said the safest way to make a vaccine available before the phase 3 trials are over was to issue an emergency use authorization for certain groups instead of a “blanket approval". "The legal, medical and scientific standard for that is that the benefit outweighs the risk in a public health emergency," said Hahn.

Earlier this month, Russia approved a coronavirus vaccine. But the vaccine called 'Sputnik V' has not yet completed its final clinical trial, which comes with the largest and most rigorous testing for a potential new drug or treatment. China has also approved a vaccine for emergency use without waiting for the completion of phase three trials.

Vaccines normally undergo three phases of clinical tests. The first two phases test the vaccine in small numbers of people for safety and may collect data on whether people make antibodies or have other responses to the vaccine. The final phase, known as phase 3, tests the vaccine in thousands of people and compares it to placebo to determine whether it is safe and effective in a general population. The last phase is crucial as it determines whether it can prevent or lower the infection. A phase 3 trial can also identify more subtle adverse effects of a vaccine that earlier trials might not have been able to. 

Last weekend, President Donald Trump criticized the FDA for moving too slowly to develop vaccines and treatments and accused it of being part of the “deep state". "The deep state, or whoever, over at the FDA is making it very difficult for drug companies to get people in order to test the vaccines and therapeutics. Obviously, they are hoping to delay the answer until after November 3rd. Must focus on speed, and saving lives," Trump tweeted. 

Soon after, the FDA granted emergency authorization of convalescent plasma to treat hospitalized Covid-19 patients despite concerns among some health officials that data from clinical trials are not sufficient to support the widespread application of the treatment yet. 

In the latest interview, however, Hahn said that the decision to issue emergency use authorization for a Covid-19 vaccine will not be for political reasons. “We have a convergence of the Covid-19 pandemic with the political season, and we’re just going to have to get through that and stick to our core principles. This is going to be a science, medicine, data decision. This is not going to be a political decision," he said. 

However, scientists cautioned that any decision regarding a coronavirus vaccine should not be made in haste. Dr Eric Topol, founder and director of Scripps Research Translational Institute said that it is "outrageous" to expedite any approval of a Covid-19 vaccine irrespective of Hahn’s "subservience" to Trump. "Any shortcuts — warped speed — will imperil the ultimate rollout of the vaccine, lose the public trust for getting immunized, which is already compromised. This could jeopardize all the extraordinary progress of the vaccine programs, no less the US exit strategy to pre-Covid life," he tweeted. 

Dr Angela Rasmussen, a virologist at Columbia University, said: "We absolutely cannot tolerate or accept an EUA for any coronavirus vaccine without reliable safety and efficacy data from phase 3 clinical trials." Writing on Twitter, she stated that it would be unethical to give the green signal before the trials had conclusively proved both the safety and efficacy of the vaccine. Issuing an emergency use approval for a vaccine without safety and efficacy data to support that would deal a “catastrophic blow” to public confidence in both vaccines and the regulatory mechanisms in place for evaluating their safety and efficacy, explained Rasmussen. “Circumventing clinical trials by issuing an EUA without safety or efficacy would place huge numbers of people at risk for massive potential harm. It makes a mockery of the very serious protections put in place to conduct clinical research ethically,” she warned.