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Physician’s note: Are the vaccination efforts against COVID-19 successful? | Coronavirus pandemic



The COVID-19 pandemic is the unprecedented crisis of our time.

To deal with it, the world’s health and scientific communities are working at unprecedented levels to develop a vaccine in just 12 to 18 months – a process that can usually take between five and 10 years.

Shortly after the appearance of the SARS-CoV-2 virus in December last year, scientists understood its molecular structure and began a huge amount of work. By mid-January, scientists knew what the virus was, understood its genetic sequence, and were able to accept it and place it on vaccine platforms that already exist around the world.

Only two months after the discovery of the virus, human clinical trials began.

Global vaccine efforts: who is involved?

There are already more than 200 vaccine candidates worldwide at some stage of development and at least 24 in the phase of human clinical trials. There has been a lot of international cooperation ̵

1; between countries, but also academic groups collaborating with small biotechnologies, small biotechnologies collaborating with larger pharmaceutical companies, and even large pharmaceutical products collaborating with each other to share some patented technologies.

One of the biggest vaccine efforts is led by the WHO in partnership with CEPI, the Epidemic Preparedness and Innovation Coalition and GAVI, the Vaccine Union. Called COVAX, the ACT Accelerator Vaccine Pillar has brought together a number of donor countries and various partners around the world to accelerate research and development of COVID vaccines.

Among the trials in the works is a vaccine from the University of Oxford in the United Kingdom based on chimpanzee adenovirus, which was previously used to develop a vaccine against Ebola; another vaccine is being developed in China, also using an adenoviral platform; the Moderna vaccine, a new platform that uses an RNA vaccine and was developed in collaboration with the National Institutes of Health in the United States; and others in Russia, India, Australia, Canada, Brazil and other countries.

modern

More than 200 coronavirus vaccine candidates are in various stages of development, with 24 prospects in human trials around the world, including those of Modern [Reuters]

What goes into finding the right vaccine?

The vaccine testing process involves different phases. It starts with laboratory research and animal experiments, then moves on to humans. Here, the first phase includes initial safety studies. They are usually given to 30 to 50 people to ensure that the vaccine is safe and has no unexpected side effects.

After clearing this stage, he moves on to phase two, a larger study that begins to look at the immunogenicity of the vaccine, which is whether it elicits the type of immune response we want to see. It then moves on to a phase three trial, which aims to test the effectiveness of the vaccine – or how well it protects a person from infection – as well as its safety in tens of thousands of people. A successful vaccine can then be licensed for use and introduced to a wider segment of the population.

Usually a company develops a vaccine, completes all the trials and tests and once they are sure it works, they start investing in and increasing production. This may take a year or more. With coronavirus, the plan is to invest in production capacity in advance and on a large scale so as to shorten deadlines.

Historically, less than 10 percent of vaccine applicants who pass the test are successful. Thus, more effort increases the chances of success.

Dr. Soumya Swaminathan

How will the vaccine work?

People who are infected with the coronavirus will naturally develop some kind of immunity to the disease. Thus, the vaccine will be given to those who have not been infected to protect them from becoming infected with the virus. However, even for those who have taken COVID-19, we still do not know how long their immunity lasts or how long they can have antibodies. This means that some people who have initial immunity may need a vaccine after one year if the antibodies do not last that long. Others who receive the vaccine may also need a booster later.

COVID-19, like other viruses, mutates as it multiplies. This may also affect the effectiveness of a future vaccine. So far, the virus has not mutated in the critical part, which is the thorn protein. Most of the vaccines developed are aimed at producing antibodies against this thorn protein. If there is a mutation there, it can make the virus weaker, which means it will no longer be as effective at infecting humans, or it can make the virus stronger, which means the vaccine will no longer work.

We need to keep studying the virus as it develops over time. Therefore, at this point, it is difficult to predict whether this vaccine will be a universal, single-dose vaccine or whether you should take it every year or two. We also don’t know if, like the flu, we have to reconstruct the vaccine every year. At this point, these are all open questions.

When will we have a viable vaccine?

Historically, less than 10 percent of vaccine applicants who pass the test are successful. Thus, more effort increases the chances of success. The fact that there are so many different developments, efforts and platforms makes us optimistic that we hope that several of them will succeed.

If any of the vaccines are effective in human clinical trials, they should be available sometime next year. But when exactly is very difficult to predict. Very optimistically, the time limit for the first doses will be the first half of 2021.

We are developing a large number of different vaccines and hope that one or more will work. But we must also be prepared for the coincidence that these initial attempts may not be successful.

Dr. Soumya Swaminathan

It is important to note that even with a successful vaccine, there will initially be a limited number of doses. We will not have eight or ten billion doses available to be able to vaccinate the whole world. We may have several hundred million doses, which means that we will have to give priority to certain sections of the population – such as front-line workers, health workers, social workers and others who are at very high risk. Production can then be increased and more vaccine candidates tested. And let’s hope that by 2022 we will be able to have many more vaccines.

How do you ensure a fair distribution of vaccines?

Through the ACT accelerator, the WHO is trying to get the parties to reach a common agreement on the fact that if all people in the world do not have access to this vaccine in a fair and just way, the pandemic problem will not be solved. As long as we have a population that is vulnerable, infected, other parts of the world can be affected. And the global economy, which suffers so much, also cannot be restarted.

We hope that all 194 WHO Member States will achieve a fair distribution framework. If everyone agrees, each country should be able to get enough doses to vaccinate high-priority groups immediately and then hopefully get more and more doses in the future. Separately, the WHO also develops clinical and public health guidelines; we hope to work through consensus, advice and dialogue to help different countries implement them.

There is also a mechanism called C-TAP, the COVID technology access platform, for anyone interested in pooling patents related to drugs, vaccines, diagnostics, new technologies and anything that could help the COVID pandemics. There are other ways to transfer technology to help large numbers of people. We hope that the companies that are developing these new tools are ready to share them in a spirit of solidarity.

A volunteer receives an injection from a healthcare professional during the first human clinical trial for a potential vaccine against the new coronavirus at Baragwanath Hospital in Soweto, South

Volunteer receives injection from a healthcare professional during a human clinical trial for a potential vaccine against the new coronavirus at Baragwanath Hospital in Soweto, South Africa [Reuters]

What if a vaccine is never found?

We are developing a large number of different vaccines and hope that one or more will work. But we must also be prepared for the coincidence that these initial attempts may not be successful.

If we don’t get a vaccine and the virus doesn’t mutate significantly, it could be a virus that continues to circulate, infecting people until enough people are immune, or some antibodies that can block transmission. This is herd immunity, which can be acquired through either a vaccine or a natural infection – but usually about 60 to 70 percent of people need antibodies to be effective. If the virus mutates, it can become stronger or softer. If it gets stronger, it can spread faster because it will grow more and make people more contagious. If it becomes less virulent, it can become a milder form of upper respiratory tract infection, similar to other coronaviruses.

Until the vaccine is developed and widely available, public health measures … must continue. We should not become complacent when we think that a vaccine is very close and will solve the problems. Is not.

Dr. Soumya Swaminathan

In the short term, we need better treatments and things like oxygen to be available in conditions where people need oxygen, we need better monitoring and better supportive care. We need to find more drugs with positive effects on recovery, such as dexamethasone for the seriously ill and remdezivir, which shortens the duration of hospitalization. We need therapeutic options before we have a vaccine and this can help save lives.

And until the vaccine is developed and widely available, the public health measures that countries currently have to slow the spread of the infection must continue. We should not become complacent when we think that a vaccine is very close and will solve the problems. Is not.

For at least a few years, until enough people have acquired immunity around the world, we will need public health measures such as contact tracking, physical distancing, quarantine, wearing masks and hand hygiene.

With or without a vaccine, the coronavirus is unlikely to disappear completely because it is now widely introduced into the human population. She is everywhere. And it can continue as a very low level of infection in the future – even when it no longer disrupts life.


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