A vaccination campaign as early as this fall ? Impossible

Une campagne de vaccination dès cet automne ? Impossible

Une campagne de vaccination dès cet automne ? Impossible

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May 29, 2020 11h24

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A vaccination campaign as early as this fall ? Impossible

The Detector rumors

Agence Science-Presse

Catherine Crépeau

Agence Science-Presse

DETECTOR RUMORS / Since the beginning of the pandemic, it is said that a vaccine could be available within 12 to 18 months. The more sanguine are even talking about a period of six months, beginning in the fall. But the fact that a vaccine is “ready” is not the end of the story, finds the Detector of rumors.

Find the right formula

Manufacturers of pharmaceutical products, innovators in biotechnology and other university labs are competing to develop a new vaccine anti-COVID-19. The world health Organization (WHO) identified, may 15, 110 vaccines in development, eight of which are in the phase of clinical trials. The London School of Hygiene & Tropical Medicine, for its part, were 169 projects of vaccines, 12 of the testing stage.

The proliferation of projects and approaches is a good news, but it does not guarantee that we will find an effective vaccine. Traditionally, only a small minority of vaccines and experimental drugs have led to a market.

In addition, achieve this in the year would be a precedent because, historically, the vaccine developed the most quickly, the one against the mumps, took four years to get from the collection of viral samples to approval, in 1967. In 2015, a speed record was established during the epidemic of the Zika, then it took seven months to develop a vaccine candidate acceptable to proceed to the stage of clinical trials. They were, however, never occurred, as the epidemic subsided of itself.

Test the recipe

The candidates for a future vaccine are first tested on human cells, then in animals. If efficacy and safety are encouraging, they pass to the stage of clinical trials in humans. These trials are conducted in three phases, with groups of volunteers are increasingly important. They are designed to assess the safety of the vaccine, the dose delivering the best immune response, side effects, and its effectiveness. They usually take 4 to 8 years. In the case of SARS-CoV-2, the current trials are not expected to be completed before the end of the year, or the spring or the summer of 2021. It will also be necessary to allow time for security checks and approval by the authorities of each country.

There is always the possibility of skipping steps. For example, leaving vaccine manufacturers to set aside some studies on animals, or by doing them in parallel with the first tests on humans. Some experts suggest to infect immunized volunteers : this type of testing gives the fastest response to a number of issues, but it also has ethical issues. Despite this, more than 24 000 people from 102 countries have signed a petition online to volunteer.

Finally, the produce

Design a vaccine in record time is one thing. But it is still necessary to be able to manufacture and distribute billions of doses, specially packed and transported at temperatures below 0 °C, in almost all corners of the world.

In theory, the existing plants could certainly produce hundreds of millions of doses by the end of the year, if the recipe was established. Moreover, many laboratories and pharmaceutical companies have announced to be ready to produce millions of doses, even if their vaccine has not yet proven its effectiveness.

But as almost everyone on the planet must be vaccinated, the existing facilities may be insufficient. Especially that we will have to continue the manufacture of vaccines against influenza, measles, mumps, and other infections. In addition, the distancing required in the plants is already declining production capacity.

As a result, new plants could be needed, which would inevitably lead to delays.

The production facilities required will also depend on the type of vaccine that will work the best. If it is a vaccine made from the virus or a protein of the virus, it should be easier to estimate the time required, since the industrial technology has existed since the 1950s. It does, however, of the time. For example, the production of the influenza vaccine is made by growing the virus in millions of chicken eggs, and each cycle takes several months.

In the case of a vaccine-RNA or DNA, which consists of the injection of the basic genetic material of the virus into the human cell to build the protein necessary, manufacture should be faster since the process is standardized. You may also need to be grown in vats of cells or in plants, such as tobacco plants. However, these types of vaccines have never been tested on a large scale.

For a vaccine based on genes, which uses a virus non-pathogenic (does not cause disease), the production is slower, because it involves the culture of animal cells. It has, however, industrial processes standardized, which is easy to produce in large quantities.

The risks of shortages

Other elements of the process can create bottlenecks. Vaccines that are composed of a protein SARS-CoV-2, or a fragment thereof, often need an adjuvant, a molecule added to stimulate the immune response. These adjuvants may require ingredients that can be rare.

The distribution could also be slowed down by a shortage of glass medical, used to manufacture the vials of vaccine, like the one that hit the United States. As to the caps of those bottles, they are produced only by a handful of companies, which increases the risk of rupture of stock.

2 billion for a vaccine

The development of a vaccine requires a lot of money. At least 2 billion u.s. dollars, according to the Coalition for Epidemic Preparedness Innovations (CEPI), an international alliance that supports the development of vaccines against epidemics. This estimate includes the development of three vaccine candidates and manufacturing, but excludes the cost of manufacturing and delivery.

Of this amount, 690 million $ have been pledged to the CEPI by various national governments. The u.s. government has given nearly a billion to support the development of candidate vaccines of Moderna Therapeutics and Johnson & Johnson. And on 21 may, the White House announced a grant of $ 1.2 billion for a vaccine are in development at AstraZeneca, stating that the “delivery” of the first vaccinations should take place in October. A schedule largely unlikely, which brings us to a month of the presidential election in November.

Verdict

Vaccines to prevent infection with the COVID-19 develop at speeds never before seen, but it is unrealistic that some of them could be available as early as the fall. Even if a vaccine proves to be hyper-efficient in the clinical trials of phase one or two that are in progress, it would still take several more months before a large-scale production and beginning of vaccination campaign.

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