Pfizer vaccine results leave questions about safety, performance: Experts

*Vaccine specialists say questions about production, distribution, performance and capability of the shot itself still need to be answered

Alexander Davis | ConsumerConnect

While it is cheering news that COVID-19 vaccine results from Pfizer Incorporated and BioNTech SE has fuelled optimism that the world will soon have a potential way out of the pandemic, yet experts have cautioned that the shot still has many hurdles to clear.

ConsumerConnect reports there are questions about production, distribution and, most importantly, the performance and capability of the shot announced Monday itself still need to be answered, even if the numbers look highly promising, according to vaccine specialists.

The Pfizer trial started less than four months ago, and how long the vaccine will confer protection and how many will benefit are almost complete unknowns for now, agency report said.

Michael Kinch, a drug development expert and Associate Vice-Chancellor at Washington University, in St. Louis, stated: “The key question still centres upon time. “Will time tell us that the protection remains useful for the larger population?”

Source stressed that in a remarkable scientific feat, which was achieved without funding from the US vaccine accelerator known as Operation Warp Speed, Pfizer and BioNTech produced positive results just over 11 months after the emergence of COVID-19 in China. An early analysis of data from the trial of more than 40,000 volunteers suggested the vaccine was more than 90% effective in preventing the illness, the partners said Monday, the same day the US surpassed 10 million total cases.

The results were published in a press release, not a peer-reviewed journal study. Nonetheless, they electrified investors, as stocks surged and bonds tumbled around the world.

The S&P closed at a two-month high, while travel and entertainment stocks rebounded after months of pandemic damage.

The likely success of the first vaccine in a large, late-stage trial raised hopes that others, like those developed by Moderna Inc. and AstraZeneca Plc with the University of Oxford, will also work.

Yet infectious disease researchers cautioned against getting too excited over the limited data that Pfizer has revealed.

Michael Osterholm, Director of the Center for Infectious Disease Research and Policy at the University of Minnesota, United States, during a radio interview Monday, November 9, 2020, said the companies’ statement “does not at all tell us about just what they’ve actually accomplished.

“It’s really too early to put any definition to what this new vaccine research shows us.”


The headline number of 90% reduction in symptomatic cases says little about what kind of cases are being prevented.

Detail on how well the vaccine works in the elderly and other vulnerable groups who most need protection is yet to come.

About half the trial participants are elderly, and it’s possible to project from the current results that the efficacy among older people should be above 80%, BioNTech Chief Executive Officer Ugur Sahin said.

More analysis is needed to be sure, he said.

According to report, a shot that prevents serious disease would be important for relieving pressure on overloaded hospitals and emergency rooms.

The current data analysis doesn’t include any severe cases, but they’re expected to occur as the study continues, Pfizer Senior Vice-President William Gruber said.

It still may be difficult to accrue the five severe cases that the US Food and Drug Administration has said it wants to see in vaccine trials, because the rate of serious infections has gone down as the pandemic progressed and treatment has improved, he said.

Pfizer expects to have accumulated two months of safety data for people in the trial in weeks’ time.

If there are no unforeseen problems, the company could apply for an emergency use authorisation in the U.S. soon after that, potentially this month.

At that point, FDA’s internal reviewers will first pore over the safety, efficacy and manufacturing data. The agency also has promised a review by outside experts to increase public confidence in any vaccine authorized. A date for that hearing hasn’t been set yet.

If an emergency authorisation is granted, a second committee of outside experts convened by the Centers for Disease Control and Prevention (CDC) will quickly weigh in to decide who should get the vaccine first. Only then will distribution begin.

All this means that even if Pfizer’s data hold up, it may be late December 2020, or even early January before a vaccine becomes available. At that point there might be around 50 million doses worldwide, enough for 25 million people.

It is recalled that Pfizer and its partner BioNTech earlier this week, announced that their vaccine candidate, BNT162b2, has emerged as the most likely weapon to defeat the Coronavirus (COVID-19).

The vaccine achieved spectacular results in a Phase 3 clinical trial, according to the drug manufacturer.

Researchers also opined that the vaccine prevented viral infection in more than 90 percent of the test subjects who received it.

That sort of efficacy is on par with the smallpox vaccine, which eradicated that disease, said they.

Dr. Albert Bourla, Chairman and CEO of Pfizer, said: “Today is a great day for science and humanity.

“The first set of results from our Phase 3 COVID-19 vaccine trial provides the initial evidence of our vaccine’s ability to prevent COVID-19.”

Many consumers believe that Pfizer’s vaccine news could not come at a better time, as the virus is fast raging particularly across the United States and Europe.

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