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November 10, 2020 1:54 pm
Over the course of this new coronavirus year, with many difficult days of isolation and fear, the world has been waiting for better times. I was hoping for more effective treatments for covid-19, faster tests, and a better understanding of how sars-cov-2 attacks the human body. Many of these things are beginning to arrive. But the main hope is that a vaccine can be found. And now it seems that the goal is closer.
On November 9, Pfizer and BioNTech, two pharmaceutical companies, announced that the vaccine they collaborated on was more than 90 percent effective in preventing symptomatic cases of Covid-19. This is a surprising result for a first generation vaccine. Many had not dared to expect an efficiency of more than 70 percent.
The response of the bags
When the US stock market opened, the news sent shares of Pfizer up 15 percent and BioNTech, a German company much smaller than the US giant, 24 percent. The hope that a vaccine could bring life back to something close to normal sent the Standard & Poor’s 500 Index soaring 3.6 percent, almost a record rise.
Shares of airlines and banks also saw increases; those of Cineworld, a chain of cinemas, increased by more than 50 percent. The main European stock exchanges had already registered increases of between 5% and 8%. Richard Hatchett, director of Cepi, a foundation that funds pandemic vaccine research, commented that the results were “extremely positive and encouraging.” He added that the finding increases the likelihood that many of the other vaccines in development will work as well.
This is important because a single covid-19 vaccine will not be enough. Pfizer-BioNTech’s product, called BNT162b2, must be kept at very low temperatures and worldwide distribution will be difficult. It also requires two administrations, three weeks apart. Many governments hope for a vaccine that can be stored closer to room temperature and requires a single dose.
The key questions
The Pfizer-BioNTech vaccine is based on the use of messenger RNA (mRNA): the technique consists of directly administering the mRNA responsible for the production of a protein normally present on the surface of viral particles. It is this protein that then triggers the immune system response. The vaccine has been tested in an ethnically diverse group of 43,000 people and the process is yet to be completed. The announced results are based on a preliminary analysis conducted by an independent data monitoring group. Companies have yet to peer review their results (Peer Review) to be published in a scientific journal.
The vaccine can prevent a person from developing symptoms of Covid-19, but it may not prevent them from being contagious anyway
The estimate of the efficacy of the vaccine may change as more data is collected. That said, the results are so remarkable that the end result is unlikely to be an extremely useful drug anyway.
But three important questions remain about the vaccine. One is how well it works in the elderly, one of the groups most vulnerable to Covid-19, who may not respond as well as the trial volunteers. Another is whether it prevents infectivity – the vaccine can prevent a person from developing symptoms of Covid-19, but it may not prevent them from being contagious anyway. And finally, its long-term effectiveness is completely unknown.
Despite this, there is no doubt that the results are extremely positive. Pfizer also says that no serious safety concerns have been raised in ongoing studies and that more data on efficacy is being collected.
It will take time
News of two more vaccines in development is also expected in the coming weeks, from AstraZeneca, another large pharmaceutical company, with a team from the University of Oxford, and Moderna, an American biotechnology company. The AstraZeneca-Oxford vaccine is already known to stimulate a good immune response in the elderly. Although the Pfizer vaccine does not work very well in this group, therefore, there is a good chance that another drug will be effective instead.
In short, the arrival of vaccines to tame the pandemic is now within reach. But it will take time. Pfizer’s next step will be to apply for emergency vaccination authorization in the US and Europe. The World Health Organization (WHO) has a procedure to allow the use of these authorizations even in countries that do not have regulatory agencies.
The BNT162b2 application will have to wait until the third week of November. Pfizer will not submit it until the trial collects two months of vaccine safety data. Regulatory agencies could authorize its use for high-risk groups (such as hospital doctors and nurses) later this year, pending more safety data; Wider approval could come in early 2021.
Distribution problems
Vaccine supplies will also initially be limited, although mass production of the BNT162b2 already started in October. There are also huge distribution challenges to tackle. The world has never carried out vaccination on such a large scale. UNICEF, the United Nations agency for children, will be one of the leading agencies in the global distribution of covid-19 vaccines. The organization purchases between 600 and 800 million syringes for routine childhood vaccines each year and estimates that covid requests will likely triple or quadruple those numbers. Both UNICEF and WHO are mapping the global availability of cold chain storage capacity to help countries receive vaccines.
In the long term, a vaccine that is 90 percent effective will achieve herd immunity. If enough people take such an effective vaccine, even those who don’t, or can’t, will be protected. However, in the short term, the priority for everyone is that the categories to be vaccinated are carefully chosen first. This will help keep the pandemic under control and ensure a faster recovery for the world economy. Travel and commerce can also return to something that is heading towards normalcy.
An efficacy of 90 percent is as close as possible to the complete protection that vaccination can aim for. It becomes an essential tool for doctors, nurses and social workers, allowing them to do their jobs with less fear. People in so many other professions will be relieved, but they will have to be patient and wait their turn.
And there is another reason to celebrate. Never before has the mRna technique adopted by Pfizer and BioNTech been shown to work in humans. The data gathered from large-scale trials of this “platform technology” allows small changes to be made to the mRNA sequence quickly and easily, thereby modifying the proteins to which the body develops immunity. This means that if new strains of covid-19 emerge, new versions of the vaccine could be quickly created to contain them.
It will likely take several months after regulatory agency approval for vaccines to affect the course of the pandemic. But this marks the beginning of the end.
This article was published in the British weekly The Economist.
To know
Waiting for scientific study
The excellent results obtained by the Pfizer and BioNTech vaccine should be read with caution because they were announced with a press release and not with a scientific article that allows them to be evaluated in detail.
Pfizer and BioNTech conducted a phase three trial with 43,538 volunteers. Half of them received the vaccine: two injections three weeks apart. The other half, the control group, received a placebo. All without the participants knowing what they received. Then they went home. The researchers then periodically checked using molecular swabs (PCR) if any of the volunteers were infected with the virus while they went about their normal daily lives (with a disease that has already killed more than 1.2 million people worldwide, and to if there is no cure, it would not have been ethical to intentionally infect them).
According to the protocol presented by Pfizer, the analyzes only considered people who had symptoms of Covid-19 at least seven days after the recall. Upon reaching 94 infected patients (of the 164 expected to terminate the study) an independent commission made a provisional analysis of the data collected so far, and found that most of the infected volunteers were part of the group that had received the placebo. Those who received the vaccine had a 90 percent lower risk of becoming infected.
Looking at the study, the percentage could vary, because the vaccine is less effective or because the immunity provided by the product is short-lived, explains Le Monde. It is not yet known how long the immunity conferred by the disease lasts. It is also not known how long the administered vaccine can last. However, the 90 percent figure seems very high. It is a coverage similar to that of vaccines against measles or rubella, which is around 95 percent, and far exceeds that of the flu, which varies between 30 and 70 percent depending on the year and age. age of the interested party. One last question remains, Le Monde continues: what will it protect against? From the disease and its symptoms, as the protocol seems to indicate, or from the infection? Faced with a pandemic spread in part by asymptomatic carriers, finding the answer seems essential.
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