6 clues to understand the importance of the Pfizer vaccine, 90% effective against Covid – Observer

“Today is a great day for science and for humanity. The first set of results from Phase 3 clinical trials of the Covid-19 vaccine provides the first evidence of our vaccine’s ability to prevent Covid-19, “said Albert Bourla, president of the chief executive officer of the pharmaceutical company Pfizer.

Pfizer and BioNTech, who created the vaccine, announced in a press release Monday that the vaccine they have in clinical trials has shown more than 90 percent effectiveness in preventing Covid-19 disease, seven days after taking it. the second dose of the vaccine, in people who had not previously been infected with the SARS-CoV-2 virus.

STAT News says this means that over 90% of participants who showed symptoms of Covid-19 (and who tested positive for the virus) had received the placebo vaccine and not the Covid-19 vaccine, i.e. nine or fewer had received the vaccine. In other words – and based on poorly understood data – those who took the vaccine were more protected than those who took the placebo.

In total there are 94 participants and the results were analyzed by a group of independent scientists. Pfizer and BioNTech say they know nothing more about the results than announced in the press release – which, according to some experts, is too little to draw conclusions about what the future will bring.

“If that value [90%] resist, it’s incredible. It’s much better than I expected and it will make a big difference, “said Ashish Jha, dean of Brown University School of Public Health, quoted by STAT News. The problem is that it’s very difficult to make a scientific assessment solely on the basis of a statement. press: scientists need to see full data.

Simon Clarke, professor of cellular microbiology at the University of Reading, remains confident: “It seems to me highly unlikely that a large pharmaceutical company will be providing the wrong information on the long-awaited news,” he said, quoted by The Guardian.

Pfizer’s vaccine is 90% effective. “Today is a great day for science and humanity,” announced the company’s CEO

In addition to the fact that full data supporting the announced conclusions has not been released, another kind of information is missing: whether the vaccine prevents severe cases of Covid-19 (those leading to hospitalization or death) or whether a person can be asymptomatic thanks to the vaccine but still transmits the virus. Of course, it is not yet possible to know how long the immunity will last: to know if the immunity lasts six or 12 months, it is necessary to follow the volunteers during that period of time.

“We need to see the real data and we will need long-term results,” said Jesse Goodman, professor of medicine and infectious diseases at Georgetown University, quoted by The New York Times.

The Pfizer / BioNTech vaccine uses messenger RNA (mRNA). In a normal situation, this mRNA carries a message from the virus’s genetic code (or from a cell) to a small cell factory where a protein will be made from that message. This vaccine does not have the genetic code of the virus, but only a portion of mRNA that is capable of inducing human cells to produce the protein. peak (which exists on the surface of the viral capsule). When cells release this protein into the bloodstream, the immune system detects it and produces antibodies. So hopefully the answer is ready for when the person is actually infected with the SARS-CoV-2 virus.

This vaccine began being developed in January when Ugur Sahin, executive director and co-founder of BioNTech, first read about the virus in the scientific journal The Lancet, and the first cases were detected in Europe, says the New York Times. .

The technology for this type of vaccine was developed earlier, although no vaccine created in this way has ever hit the market. The advantage is that, with the facility in place, it is relatively quick to search for potential vaccine candidates. BioNTech found 20 candidates that it immediately began testing in rodents, but lacked the ability to conduct clinical trials in humans. This is how the partnership with Pfizer was born. In the first human clinical trials, the two companies chose the two vaccines that elicited the best immune responses: with antibodies and T cells.

Moderna also has an mRNA-based vaccine and is also advanced in Phase 3 clinical trials. Other companies have vaccines based on attenuated forms of the virus or viral proteins, for example.

Although some experts show some caution because the data that led pharmaceutical companies Pfizer and BioNTech to say that the initial data showed an efficiency greater than 90% is not yet known, others are satisfied with the results and other data that can be removed. beyond effectiveness.

1. A protein peak which helps the virus to enter the cell is a good choice

“There was always a discussion as to whether protein peak was the right target for vaccines? Well, now we know it is, “Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID), told STAT News.” So, it’s not just immediate good news, it gives confidence in what will happen next. months with other vaccines “.