Questions raised by Pfizer and BioNTech's vaccine announcement

Pfizer vaccine -

• While several candidate vaccines against Covid-19 are in phase 3 of clinical trials, Pfizer and BioNTech announced on Monday that their vaccine would be 90% effective.

• An announcement obviously promising, but that the scientific community welcomes with caution, while waiting to have complete data on its efficacy and safety.

• For its part, the European Union has already positioned itself and has pre-ordered 300 million doses, in the event that the efficacy of this vaccine is confirmed.

This is the news that everyone was waiting for, which made the stock market soar and which suggests a glimmer at the end of the long tunnel of this pandemic.

A vaccine jointly developed by Pfizer (United States) and BioNTech (Germany) would be 90% "effective" in preventing Covid-19 infections, according to the large-scale phase 3 trial underway, last step before an application approval, the two laboratories announced on Monday.

According to the World Health Organization (WHO), ten vaccine clinical trials are currently in phase 3 around the world, including those of the American biotech Moderna, several Chinese state laboratories and the British AstraZeneca, in collaboration with the Oxford University.

But the Pfizer-BioNTech couple is to date the first to release intermediate results.

WHO Director General Tedros Adhanom Ghebreyesus praised "the encouraging vaccine news" from the two firms.

“The world is experiencing unprecedented innovation and scientific collaboration to end the pandemic!

", he added.

But does this announcement mean that the vaccine is effective and safe enough to be licensed soon?

What does Pfizer use to ensure that its vaccine is 90% effective?

Pfizer says it started its "phase 3 clinical trial on July 27 and recruited a cohort of 43,538 volunteers" to test its vaccine, BNT162b2.

Participants divided into two groups: one, of 38,955 participants, received the vaccine in two injections, and the other a placebo.

According to the laboratory, patient protection was achieved seven days after the injection of the second dose of the vaccine and 28 days after the first, based on preliminary results.

The “vaccine efficacy rate of more than 90%” was measured by comparing the number of participants infected with the coronavirus in the group that received the vaccine and in that on placebo, explain Pfizer and BioNTech.

These results come from the first interim analysis of their large-scale phase 3 trial, prior to a license application.

This analysis was conducted after 94 trial participants contracted the coronavirus.

Scientists then determined how many of those infected participants received the vaccine or the placebo.

Data not disclosed to date and that Pfizer wishes to complete, by continuing its clinical trial until 164 positive cases for Covid-19 have been identified among the cohort.

These data have not yet been published in a scientific journal.

But that does not prevent the American laboratory from displaying a victorious enthusiasm.

“More than eight months after the start of the worst pandemic in more than a century, we believe this step represents a significant step forward for the world in our battle against Covid-19,” said the President and CEO of Pfizer, Albert Bourla, in a statement.

“The first set of results from our Phase 3 Covid-19 vaccine trial provide initial evidence of our vaccine's ability to prevent Covid-19,” he adds.

How is this announcement received by the scientific community?

If the announcement is necessarily exciting, the scientific community refuses to get carried away and awaits additional data.

"Obviously, if it is proven that this vaccine is really effective, it would be very good news, bearer of hope, but we must wait to have precise figures, indicates to 

 Professor Daniel Floret, vice-president of the Technical Committee on Vaccinations, attached to the High Authority for Health (HAS).

Firms are always enthusiastic about their product, but you can't just rely on a press release.

Pfizer talks about the vaccine being 90% effective, but how to interpret this announcement?

Is the vaccine effective in preventing disease, transmission of infection?

Tests show that anti-Covid vaccines induce an immune system response, but immune response and protection are not the same thing, specifies Professor Floret.

And what are the safety data for this vaccine?

Because if it is effective, is it safe and without side effects?

For now, as long as no data has been published and analyzed by independent experts, there is nothing.

You should be careful.

The results of clinical trials must be sent to the various drug agencies, which will analyze them ”.

A caution shared by Professor Gilbert Deray, head of the nephrology service at the Pitié-Salpêtrière hospital (Paris), for whom this announcement brings "real hope", but leaves several "questions unanswered.

How long does the immunity last?

What are the side effects ?

Are severe forms also avoided?

Are the most fragile immune?

“Asks the doctor on Twitter.

Pfizer vaccine open questions:

Confirm initial results.

How long does the immunity last?

What are the side effects, ?

Are severe forms also avoided?

Are the most fragile immune?

We remain cautious even if hope is there.

- deray gilbert (@GilbertDeray) November 9, 2020

For its part, Pfizer wants to be reassuring.

“The data monitoring committee did not report any serious safety concerns and recommends that the study continue to collect additional safety and efficacy data as expected, assures the firm.

The data will be discussed with regulatory authorities around the world ”.

According to a European source, the European Medicines Agency (EMA) is examining the data of this famous vaccine developed by Pfizer and BioNTech.

If the vaccine's efficacy is confirmed, when will it be available and will there be something for everyone?

For now, "Pfizer and BioNTech continue to accumulate safety data."

Before the issuance of a potential authorization for emergency use of the vaccine by the US drug agency (FDA), the two laboratories must observe and analyze its effects for “two months after the second (and last) dose”.

Data which should therefore be available "by the third week of November," says Pfizer.

Then, good news, the very nature of this vaccine means that, if its effectiveness is demonstrated and the drug agencies authorize its marketing, its production could be rapid.

"RNA vaccines have the interesting feature of being able to be produced very easily in very large quantities", underlines Professor Floret.

In addition, "the firms have put themselves in a position to be able to produce vaccines very quickly, they have already anticipated the production of millions of doses," he adds.

But it will necessarily be gradual, and many countries have made pre-orders, so there will be discussions about who will have the first doses available ”.

So when can we expect an anti-Covid vaccine to be marketed?

“In all likelihood, there will not be just one vaccine but several, probably in the second half of 2021, reassures Professor Floret.

But we must be aware that we will not be able to vaccinate the world population in just a few months.

It will take time to produce several billion doses if one or two injections are needed for each person ”.

Pfizer and BioNTech have declared that they plan to provide up to 50 million doses worldwide in 2020 and up to 1.3 billion in 2021. And the EU has already positioned itself to source: The European Commission reached a preliminary agreement in September with BioNtech and Pfizer to pre-order 300 million doses of their potential vaccine.

But it is not the only one: the United Kingdom hopes to procure 10 million doses by the end of the year, and the United States has already signed a contract with Pfizer for the delivery of 100 million doses.

In France, the HAS is already working on the vaccine strategy to be implemented, and is counting on priority access for vulnerable people and health professionals.

Health

Coronavirus: Pfizer announces that its vaccine candidate is 90% "effective"

Economy

Coronavirus: The announcement of a 90% effective vaccine sends the European stock market soaring

• Covid 19

• Coronavirus

• Health

• Pharmaceutical industry

• Vaccine

• Vaccination

• epidemic