Pfizer’s Covid Vaccine: 11 Things You Should Know



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In July, Pfizer and BioNTech launched an advanced clinical trial of a vaccine against the coronavirus. Half of the people received the vaccine, while the other half received a saltwater placebo. Companies then waited for people to get sick to determine if the vaccine offered protection.

So far, 94 out of nearly 44,000 participants have fallen ill with Covid-19. An independent expert panel examined how many of these people received the vaccine and how many received the placebo. This first analysis suggests that the vaccine is more than 90% effective.

As is the norm for clinical trials, the data was “blinded,” meaning that no one other than the independent board – not volunteers, doctors, or company executives – knows how many of the 94 people affected. by the virus received the vaccine or the placebo. Given the estimate that the vaccine is over 90% effective, we can, however, assume that very few vaccinated people have contracted Covid-19.

It is. The Food and Drug Administration had set an efficacy bar of 50% for vaccine manufacturers who wanted to submit their applicants for emergency clearance. If the preliminary results from Pfizer and BioNTech confirm this – and accurately reflect how the vaccine works in the real world – then it is far more protective than that.

To get an idea of ​​the quality of these results, it is worth considering licensed vaccines that people receive regularly. At the lower end, influenza vaccines are 40-60% effective at best, as the influenza virus continues to evolve into new forms year after year. In contrast, two doses of the measles vaccine are 97% effective.

Credit…University of Maryland School of Medicine, via Associated Press

So far, Pfizer and BioNTech have not reported any serious safety concerns with their vaccine. Prior to conducting the current large-scale study, the companies conducted smaller clinical trials starting in May, specifically designed to detect warning signs of vaccine safety. They tried four versions of their vaccine and selected the one that produced the fewest cases of mild and moderate side effects, such as fever and fatigue.

If their vaccine receives emergency clearance from the FDA and is distributed to millions of people, the Centers for Disease Control and the FDA will monitor them to make sure there is no evidence of even more safety concerns. rare.

Trial participants will also be followed for two years.

Credit…Taylor Glascock for The New York Times

The chief executive of Pfizer said he could have 30 to 40 million doses of the vaccine before the end of the year, enough for 15 to 20 million people to receive an initial injection and a booster three weeks later.

It has not been decided exactly who will be eligible for initial doses, but groups who are at a higher risk of infection or who are more vulnerable to the virus will likely be given priority. This could include healthcare workers as well as older adults and those with risk factors like obesity or diabetes.

Pfizer and BioNTech say they could increase to 1.3 billion doses per year. This is still far from sufficient to meet the world’s vaccine needs. If other vaccines prove to be equally effective, companies will be able to manufacture them as well and help meet demand.

Pfizer said it would likely apply for emergency clearance in the third week of November, after collecting the two months of safety data the FDA has asked manufacturers to submit. Then the agency will consult with an external expert advisory board and it may take weeks to review detailed data on the safety, vaccine effectiveness and the ability of companies to safely manufacture millions of doses. .

The vaccine could be cleared for some high-risk populations before the end of the year, but that will only happen if everything goes as planned and there are no unforeseen delays.

Credit…Ralph Orlowski / Reuters

The trial will continue until it reaches 164 cases of Covid-19. At this point, the study will be completed and the results analyzed.

While the preliminary results offer compelling evidence for the vaccine’s effectiveness, they don’t tell us for sure how effective it is. Clinical trials just aren’t designed for this. They cannot allow scientists to make an estimate based on statistics – an estimate known as efficiency. The effectiveness of a vaccine can only be firmly determined after millions of people have received it. But experts say preliminary data indicates the efficacy is expected to be very high.

The new results also don’t tell us whether older people will have strong protection from the vaccine. Pfizer and BioNTech’s clinical trial includes people over the age of 65, so it will eventually provide this crucial information. Early clinical studies suggested that older people produce a weaker immune response to coronavirus vaccines. But with such strong preliminary evidence, it’s possible that they still get strong protection from a vaccine.

Another open question is whether children will benefit from protection from the vaccine. The trial led by Pfizer and BioNTech was initially open to people 18 years of age or older, but in September they started including teens as young as 16. Last month, they launched a new trial on children as young as 12 and plan to get closer to younger ones. age.

Credit…Pool photo by Saul Loeb

Vice President Mike Pence said on Monday Twitter that the news has come “Thanks to the public-private partnership forged” by Mr. Trump.

In July, Pfizer struck a $ 1.95 billion deal with the government’s Operation Warp Speed, the multi-agency effort to rush a vaccine to market, to deliver 100 million doses of the vaccine. . The arrangement is an advance purchase agreement, which means the company won’t be paid until they deliver the vaccines. Pfizer did not accept federal funding to help develop or manufacture the vaccine, unlike pioneers Moderna and AstraZeneca.

Pfizer has distanced itself from Mr. Trump and Operation Warp Speed. In an interview on Sunday, Kathrin Jansen, senior vice president and head of vaccine research and development at Pfizer, said: “We have never been part of Warp Speed,” adding: “We have never taken money from the US government, or anyone. “

On Monday, a spokeswoman for Pfizer clarified that the company was part of Operation Warp Speed ​​as a supplier of a potential vaccine against the coronavirus.

While it’s true that Pfizer and BioNTech had been working on a vaccine all year before the companies reached their deal with the U.S. government in July, a $ 1.95 billion deal is nonetheless a significant incentive to continue. . In fact, international health organizations have long used these market guarantees to encourage for-profit manufacturers to supply vaccines to developing countries.

There are 10 other vaccines currently in late trials around the world. The fact that Pfizer and BioNTech have achieved encouraging results makes experts optimistic across the field.

“This gives us more hope that other vaccines will also be effective,” said Akiko Iwasaki of Yale University.

Pfizer and BioNTech are testing a vaccine that uses a genetic molecule called RNA to trick our own cells to make a viral protein. Our immune system encounters the protein and makes antibodies and immune cells capable of quickly recognizing the protein and triggering a rapid attack. Moderna is at an advanced stage of trials with its own RNA vaccine, and early clinical trials of other RNA vaccines are underway in China, England, India, Singapore, South Korea and Thailand .

But the news from Pfizer and BioNTech could also be encouraging for other vaccine developers. The vaccine from Pfizer and BioNTech causes our bodies to make a viral protein called a spike. A number of other vaccines deliver the spike protein into the body, or just a fragment of it, which prompts the immune system to recognize it. Still other vaccines are based on other viruses, which safely deliver a gene for the spike protein into cells. If the spike protein induces strong protection against the coronavirus, then all of these vaccines could give encouraging results in the coming months as well.

The widespread success of coronavirus vaccines would be of huge benefit to global health, as Pfizer and BioNTech alone cannot meet the total demand.

Please do not do it. The coronavirus is raging across the country and public health experts have said Americans need to prepare for a very harsh winter.

Even though a vaccine is cleared within months, it will initially only be available to a portion of the American public. Most health officials believe that an effective vaccine won’t be available to anyone who wants it until next year. Even so, there is still no data on whether a vaccine will stop the asymptomatic spread of the virus or to what extent it will prevent people from developing severe Covid-19.

Most experts say that even when a vaccine is widely available, additional measures such as masks will still be needed until the threat to public health has abated.

“It will not replace hygiene measures – it will be a supplement to hygiene measures,” said Dr. Paul Offit, a professor at the University of Pennsylvania and a member of the FDA’s vaccine advisory committee. “You owe it to others to make sure you wear a mask.”



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