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When will a coronavirus vaccine be ready? | World news

ISFri to their most effective – and draconian – containment strategies have only slowed the spread of Covid-19 respiratory disease. With the World Health Organization finally declaring a pandemic, all eyes have turned to the prospect of a vaccine, because only a vaccine can prevent people from getting sick.

About 35 companies and academic institutions are running to create such a vaccine, at least four of which already have candidates who have tested on animals. The first of these – produced by the modern biotechnology company in Boston – will enter human experimentation in April.

This unprecedented speed is largely due to early Chinese efforts to sequence the genetic material of Sars-CoV-2, the virus that causes Covid-19. China shared this sequence in early January, allowing research groups around the world to grow the virus alive and study how it invades human cells and makes people sick.

But there is another reason for the advantage. Although no one could have predicted that the next infectious disease that threatened the globe would be caused by a coronavirus – influenza is generally considered to be the greatest risk of a pandemic – vaccinologists had covered their bets by working on “prototype” pathogens. “The speed with which we have [produced these candidates] relies heavily on investing in understanding how to develop vaccines for other coronaviruses, “says Richard Hatchett, CEO of Oslo-based nonprofit, the Coalition for Epidemic Preparedness Innovations (Cepi), which is leading efforts to fund and coordinate the Covid-19 vaccine development.

Coronaviruses have caused two more recent outbreaks: severe acute respiratory syndrome (SARS) in China in 2002-04 and Middle Eastern respiratory syndrome (MERS), which began in Saudi Arabia in 2012. In both cases, work began on vaccines that were later shelved when the outbreaks were contained. A company, Maryland-based Novavax, has now revived those vaccines for Sars-CoV-2, and claims to have several candidates ready to enter human trials this spring. Moderna, meanwhile, has relied on previous work on the Mers virus conducted at the American National Institute of Allergies and Infectious Diseases in Bethesda, Maryland.

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Sars-CoV-2 shares between 80% and 90% of its genetic material with the virus that caused Sars, hence its name. Both consist of a ribonucleic acid (RNA) strip inside a spherical protein capsule covered with spikes. The spikes attach to the receptors on the surface of the cells that line the human lung – the same type of receptor in both cases – allowing the virus to penetrate the cell. Once inside, it hijacks the cell’s reproductive mechanism to produce multiple copies of itself, before exiting the cell again and killing it in the process.

President Xi Jinping learned about progress in the vaccine field at the Beijing Academy of Military Medical Sciences on March 2.

President Xi Jinping learned about progress in the vaccine field at the Beijing Academy of Military Medical Sciences on March 2. Director of photography: EPA

All vaccines work on the same basic principle. They present part or all of the pathogen to the human immune system, usually in the form of an injection and at a low dose, to induce the system to produce antibodies to the pathogen. Antibodies are a kind of immune memory that, after being solicited once, can be rapidly mobilized again if the person is exposed to the virus in its natural form.

Traditionally, immunization has been achieved using live and weakened forms of the virus, or part or part of the virus once it has been inactivated by heat or chemicals. These methods have disadvantages. The live form can continue to evolve in the host, for example, potentially recovering part of its virulence and making the recipient sick, while higher or repeated doses of the inactivated virus are needed to achieve the necessary degree of protection. Some of the Covid-19 vaccine projects are using these proven approaches, but others use newer technology. A more recent strategy – the one Novavax is using, for example – builds a “recombinant” vaccine. This involves extracting the genetic code for the protein peak on the surface of Sars-CoV-2, which is the part of the virus that most likely causes an immune reaction in humans, and pastes it in the genome of a bacterium or yeast. , forcing these microorganisms to churn out large quantities of protein. Other approaches, even more recent, bypass proteins and build vaccines from genetic education itself. This is the case with Moderna and another Boston company, CureVac, which are both building Covid-19 vaccines with messenger RNA.

Cepi’s original portfolio of four Covid-19 funded vaccine projects was heavily distorted compared to these more innovative technologies and last week announced $ 4.4 million (£ 3.4 million) of funding in partnership with Novavax and a vector vaccine project from the University of Oxford. “Our experience with vaccine development is that you can’t predict where you’re going to stumble on,” says Hatchett, which means diversity is the key. And the stage where any approach is more likely to stumble is clinical or human testing, which, for some of the candidates, is about to begin.

Clinical trials, an essential precursor to regulatory approval, generally take place in three stages. The first, which involves several dozen healthy volunteers, verifies the safety of the vaccine, monitoring for adverse effects. The second, which involves several hundred people, usually in a part of the world affected by the disease, examines the effectiveness of the vaccine and the third does the same in several thousand people. But there is a high level of friction as experimental vaccines go through these stages. “Not all horses that come out of the starting gate will finish the race,” says Bruce Gellin, who runs the Washington DC-based global immunization program for nonprofits, the Sabin Vaccine Institute, and is partnering with Cepi for a vaccine. Covid-19.

Boris Johnson visits the Mologic Laboratory in Bedfordshire, where scientists are working on faster tests for Covid-19, March 6.

Boris Johnson visits the Mologic Laboratory in Bedfordshire, where scientists are working on faster tests for Covid-19, March 6. Photography: Getty Images

There are good reasons for this. Either the candidates are not sure or are ineffective or both. Dud screening is essential, which is why clinical trials cannot be skipped or rushed. Approval can be accelerated if regulators have approved similar products previously. The annual flu shot, for example, is the product of a well-refined assembly line where only one or a few modules need to be updated every year. In contrast, Sars-CoV-2 is a new pathogen for humans and many of the technologies used to build vaccines are also relatively untested. To date, no vaccines based on genetic material – RNA or DNA – have been approved. So candidates for the Covid-19 vaccine must be treated like new vaccines, and as Gellin says: “While there is a push to get things done as fast as possible, it is really important not to take shortcuts.”

One example is the vaccine produced in the 1960s against respiratory syncytial virus, a common virus that causes cold-like symptoms in children. In clinical studies, this vaccine has been found to aggravate these symptoms in children who have continued to take the virus. A similar effect has been observed in animals given an early experimental Sars vaccine. It was subsequently modified to eliminate that problem but, now that it has been re-proposed for Sars-CoV-2, it will have to undergo particularly rigorous safety tests to rule out the risk of advanced diseases.

It is for these reasons that bringing a vaccine candidate to regulatory approval typically takes a decade or more, and because President Trump sowed confusion when, at a meeting in the White House on March 2, he insisted that a vaccine be ready. for the US elections in November – an impossible deadline. “Like most vaccinologists, I don’t think this vaccine will be ready before 18 months,” says Annelies Wilder-Smith, professor of emerging infectious diseases at the London School of Hygiene and Tropical Medicine. It is already extremely fast and assumes that there will be no hitches.

In the meantime, there is another potential problem. As soon as the vaccine is approved, it will be needed in large quantities – and many of the Covid-19 vaccine race organizations simply don’t have the necessary production capacity. Vaccine development is already a risky business, in commercial terms, because so few candidates arrive anywhere near the clinic. The production facilities tend to be adapted to specific vaccines and to scale them down when it is not known yet whether the product will be successful is not commercially feasible. Cepi and similar organizations exist to take part of the risk, keeping companies incentivized to develop much needed vaccines. Cepi plans to invest in developing a Covid-19 vaccine and upgrading parallel production capacity, and earlier this month launched a $ 2 billion request to allow it to do so.

Once a Covid-19 vaccine is approved, a further set of challenges will arise. “Getting a vaccine that has been shown to be safe and effective in humans takes about a third of what is necessary for a global immunization program at best,” says Duke University of North Carolina global health expert Jonathan Quick, author of The end of epidemics (2018). “Virus biology and vaccine technology may be the limiting factors, but politics and the economy are far more likely to be the barrier to immunization.”

Donald Trump at the National Institutes of Health's Vaccine Research Center in Maryland, March 3. The president sowed confusion by pressing for a vaccine to be ready for the U.S. election.

Donald Trump at the National Institutes of Health’s Vaccine Research Center in Maryland, March 3. The president sowed confusion by pressing for a vaccine to be ready for the U.S. election. Photography: Brendan Smialowski / AFP via Getty Images

The problem is making sure the vaccine reaches everyone who needs it. This is also a challenge within countries and some have developed guidelines. In the scenario of a flu pandemic, for example, the UK would prioritize vaccinations from healthcare and social care workers, along with those considered to be at the highest medical risk – including children and pregnant women – with the overall goal of keep disease and death levels as low as possible. But in a pandemic, countries also have to compete with each other for medicine.

Since pandemics tend to hit those countries that have the most fragile and underfunded health systems harder, there is an inherent imbalance between need and purchasing power when it comes to vaccines. During the 2009 H1N1 flu pandemic, for example, supplies of vaccines were purchased from countries that could afford them, leaving the poorer ones short. But you could also imagine a scenario where, for example, India – a major vaccine supplier for developing countries – unreasonably decides to use its vaccine production to protect its 1.3 billion population first of people, before exporting any.

Outside of the pandemics, WHO brings together governments, charitable foundations and vaccine manufacturers to agree on a fair global distribution strategy, and organizations such as Gavi, the vaccine alliance, have developed innovative funding mechanisms to raise funds. on the markets to guarantee supply to poorer countries. But each pandemic is different and no country is bound by any agreement proposed by the WHO, leaving many unknowns. As Seth Berkley, CEO of Gavi points out: “The question is: what will happen in a situation where national emergencies occur?”

This is under discussion, but it will take a while before we see how it goes. The pandemic, Wilder-Smith says, “will likely have peaked and declined before a vaccine is available.” A vaccine could still save many lives, especially if the virus becomes endemic or circulates perpetually – like the flu – and there are additional, possibly seasonal, outbreaks. But until then, our best hope is to contain the disease as much as possible. To repeat the wise advice: wash your hands.


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