COVID-19: Pfizer hopeful of vaccine success in trials

By Backend Office, Desk Reporter
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Pfizer, the US based drugmaker, is betting that its coronavirus vaccine candidate will show strong signs of success early in its clinical trial, says reports.

Pfizer has said in recent weeks that it should know by the end of October whether the vaccine, created together with BioNTech SE in Germany, is safe and reliable. If the vaccine has been shown to succeed by then, Pfizer said it would immediately seek approval by the regulators .

President Donald Trump, who is seeking re-election, said a vaccine that is capable of tackling the coronavirus pandemic will be possible before the US vote on November 3, raising questions about political interference. Scientists have questioned whether, by that time, drugmakers would have enough proof to achieve success.

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Pfizer protocol

Pfizer’s clinical trial procedure explains how the drugmaker will demonstrate that the vaccine meets the expectations of effectiveness and safety of the Food and Drug Administration (FDA) of the US.

The protocol demands that the monitoring board first evaluate the efficiency of the vaccine after 32 trial participants become infected with the novel coronavirus. Over 29,000 people have so far registered in the trial that began in July, some receiving the vaccine and others receiving a placebo. Placebo is something that has no therapeutic effect and is used in researches for a comparative study.

The FDA has said that in a large-scale trial, to be eligible for approval, a coronavirus vaccine must appear to be at least 50 percent more successful than a placebo. However, according to experts, a smaller sample of infections in a clinical trial changes the estimation of how the standard is met.

According to their protocol, Pfizer’s vaccine will need to be at least 76.9 percent successful to prove that it works. That would mean that no more than 6 out of the 32 individuals who obtain the vaccine should have coronavirus, the documents revealed.

In this first study, if the drugmaker’s vaccine fails to reach the 76.9 percent efficacy goal, it will face tougher statistical requirements during subsequent evaluations, said biostatisticians who reviewed the protocol.

Interim Analysis

Data and safety review boards usually use interim analysis to assess if an experimental drug appears to be safe and successful enough to begin a trial, or if it should be halted if a safety issue occurs.

But if a vaccine meets FDA benchmarks at an interim review with no significant safety concerns, it could make sense to use it as a basis for authorization to help curb a pandemic that has killed around 940,000 people worldwide.

Moderna, another front-runner in the vaccine race, said that if an interim review of its trial found that its vaccine was at least 70 percent successful, it would seek emergency FDA permission to use its vaccine in high risk groups.

Some vaccine experts have said drugmakers must wait until their final review of more than 150 cases before seeking approval from the FDA. They point out the pace at which vaccines for COVID-19 are being developed, taking only months for what is generally a decade long process.

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