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The world is close to producing a vaccine against the Covid-19 epidemic, just one year after the appearance of the new disease caused by the emerging corona virus, in a goal that has been achieved thanks to an investigation that has been running to record speed, despite several question marks remaining.
When will the vaccine be available?
November was crucial, when the manufacturers made their first announcements about the effectiveness of the vaccines they were working on.
In Europe, the European Medicines Agency confirmed this Monday to Agence France-Presse that it will be able to grant the license for the first vaccinations before the end of the year or early 2021. As of these dates, many countries have prepared his plans in recent days, such as Spain, Italy and France.
For its part, the United States expects to start a vaccination campaign in mid-December, as soon as the license is obtained from the Food and Drug Administration.
In turn, the Chinese authorities have given the green light for the emergency use of some vaccines manufactured by their companies.
This breakthrough in the field of vaccines was made possible by acceleration, on all fronts, of research, industrial production and evaluation, supported by massive funding. Typically, it takes ten years to develop and launch a new vaccine on the market.
The European Medicines Agency stresses that “the same regulatory standards related to quality, safety and efficacy are based on vaccines against COVID-19.” However, whatever the date of official approval of vaccines, not the entire population of the Earth will not be vaccinated at once.
Recently, the director general of the World Health Organization, Tedros Adhanom Ghebreyesus, stated that, “in the first stage, the quantities of vaccine will be limited and the priority will be for the most vulnerable groups.”
Another important dilemma that will arise in this context is the equality between poor and rich countries in obtaining vaccines.
For Gebresus, “the vaccines were developed with urgency, and their equitable distribution must also be an urgent matter,” adding, on Monday, that the poor and most vulnerable countries “face the risk of being ignored amid the influx of vaccines. “.
Which vaccine is the best?
It is not possible to answer this question at this time.
Since November 9, four manufacturers have declared their vaccines effective: the American-German alliance “Pfizer / Biontech”, the American laboratory “Moderna”, the British alliance “AstraZeneca / Oxford” and the Russian governmental institute “Gamalia”.
Despite this advertising rush, which gave global stock exchanges a boost, the figures were only revealed in press releases and without publishing detailed scientific data.
The results depend on the final or third phase of a clinical trial, which has undergone tens of thousands of volunteers. Efficacy is measured by comparing the number of people who got the disease in the group that got the vaccine with those who got it in the group that got the sham vaccine. It was revealed after a predetermined number of volunteers fell ill: 170 for “Pfizer / Biontec”, 95 for “Moderna”, 131 for “AstraZeneca / Oxford” and 39 for “Gamalia”.
The effectiveness of the vaccine, “Pfizer / Biontec”, reached 95%, from the 170 infected, only 8 were from the vaccinated group and 162 from the group that did not receive the vaccine.
Regarding the effectiveness of the “Moderna” vaccine, it reached 94.5 percent (5 patients in the group that received the vaccine, 90 in the group that received the sham vaccine).
On the other hand, the efficacy rate of the Russian “Sputnik-V” vaccine is 91.4 percent compared to the number of 39 patients, and 95 percent compared to the number of unidentified patients.
The calculations adopted by “AstraZeneca / Oxford” are more complex. The vaccine effectiveness rate is an average of 70 percent, if the results of two different protocols are combined. The effectiveness was 90 percent in volunteers who received an initial half dose and then a full dose a month later. The percentage drops to 62 percent in another group, which received two full doses, a difference of one month between the first and the second. This indicates that the first vaccination method achieved a better immune response.
However, effectiveness is not all that counts. AstraZeneca is the cheapest vaccine (around € 2.50 per dose). As for the “Moderna” and “Pfizer / Biontech” vaccines, they have no logistical obstacles, since the technology used for their manufacture requires prolonged storage at very low temperatures (minus 20 for the Moderna vaccine and minus 70 degrees for the vaccine. “Pfizer”).
What are the questions that still have no answer?
Many questions remain. Have The director general of the Health Organization warned that “the vaccine will complement other means that we have, and will not replace them”, although “the light at the end of the tunnel is stronger.”
The most important question relates to the long-term effectiveness of the vaccine, because the issued accounts were prepared only two weeks after the volunteers received the last dose.
British expert Benny Ward from King’s University in London, quoted by the Science Media Center, asks: “How long does protection last? Will the virus be able to transform itself to evade the vaccine, thus limiting the effectiveness of vaccination?”
Another basic question that arises: it is not yet clear if the vaccine interacts in the same way with the most vulnerable population group, starting with the elderly who have a weak immune system. They are more susceptible to severe forms of the disease and therefore it is important that the vaccine is useful for them.
Finally, it remains to be seen if the vaccine prevents the transmission of the infection, in addition to reducing the severity of the disease among those who received it. This is a very essential point to stop the epidemic.
In context, experts believe that in this field “AstraZeneca / Oxford” has an advantage over other vaccines.
University of Edinburgh academic Eleanor Riley, reported by the Science Media Center, stated that, “Unlike what happened in other experiments, the + AstraZeneca / Oxford + team screened all participants each week for lesions without symptoms”.
For its part, the University of Oxford confirmed that it has “initial indications that the vaccine is capable of preventing the transmission of infection, because a decrease in the number of asymptomatic infections has been observed.”
In an interview with “France Press”, “AstraZeneca” said that the systematic detection of asymptomatic patients does not concern all 23,000 volunteers, but only a part of them, without announcing the expected number.
Finally, if the trials did not show serious side effects, a “continuous monitoring” process is necessary to ensure that “there are no rare, unwanted but more serious effects when the vaccine is used on a larger scale,” according to Dr. Ward.
How many vaccines are offered?
Of the four vaccines that have reached an advanced stage, 11 are in the third phase of trials, according to the latest announcement from the World Health Organization on the matter, dated November 12. Among them, many Chinese laboratory projects (such as “Sinovac”, “Sinopharm” and “Cansino”).
In all, there are 48 “candidate vaccines” that are being tested in humans around the world. In addition to the 11 vaccines in the third testing phase, there are 37 in the first phase (which aims to evaluate the safety of the product) and the second (which studies its effectiveness).
In addition to those that have already entered the testing phase, WHO is counting 164 vaccine projects in the preclinical phase.
What techniques are used?
The labs used different methods, some proven and new.
Several teams are working with traditional means, such as the “inactivated” vaccine technique that is developed through a virus whose infectious agents have been treated, and is the technique used by “Sinovac” and “Sinopharma” of the Chinese.
There are also recombinant proteomic vaccines, which are based on creating an immune response through proteins and not through a virus.
Likewise, more sophisticated “viral vector” vaccine technology is being used as the basis for another virus that is transforming and adapting to combat Covid-19. And “AstraZeneca / Oxford” works with this technology, like the Russians, who are based on developing their vaccine against an adenovirus.
Finally, the most practical projects are based on “DNA” or “messenger RNA” vaccines. This technology is based on pumping genetic instruction molecules into cells, to drive them to make proteins or “antagonists” directed against the Corona virus. Moderna and Pfizer / Pinotech are working with this technology.
Will people trust the vaccine?
Whatever the first dates of vaccination campaigns, a fundamental question remains, which is whether people will agree to receive the vaccine in a context of significant increase in mistrust.
According to a study published in mid-October in the British journal “Royal Society Open Science”, a good part of the population of some countries believes in conspiracy theories related to Covid-19, which increases their distrust of the vaccine.
For example, 22 percent of the Mexicans surveyed in this study believed in the validity of a false notion that the epidemic “is part of a plan to impose worldwide vaccination.”
Research published in early November by the World Economic Forum and conducted in 15 countries showed that the percentage of people prepared to receive the vaccine decreased compared to August. Only 73% support the following statement: “If there is a vaccine available against Covid-19, I will get vaccinated”, compared to 77% in August.
