The US Food and Drug Administration is considering options for a vaccine that prevents the disease. (File)
The desperation for a way to keep economies from collapsing under the weight of Covid-19 could mean settling for a vaccine that keeps people from getting really sick or dying but doesn’t keep them from getting it. coronavirus.
Although a knockout against the virus is the ultimate goal, early vaccines may come with limits on what they can provide, according to Robin Shattock, a professor at Imperial College London leading the development of a experimental vaccine.
“Is it protection against infection?” Shattock said. “Is it protection against disease? Is it protection against serious disease? It is quite possible that a vaccine that protects only against serious disease will be very useful.”
While the countries are cautiously emerging from the blockages, the leaders are considering a preventive plan as a way to return to pre-pandemic life. Fueled by billions of dollars of government investment, vaccines from little-known companies like the Chinese company CanSino Biologics Inc. and giants like Pfizer Inc. and AstraZeneca Plc are under development.
At least one of the fastest experimental shots has already progressed in human trials after showing an impact on serious illnesses – but less on infections – in animals. Experts say such a product would likely be widely used if approved, even if it contributes as much, until a more effective version hits the market.
“Vaccines must protect against disease, not necessarily against infection,” said Dennis Burton, immunologist and vaccine researcher at Scripps Research in La Jolla, California.
Always sensitive
There are drawbacks, however. While having the potential to save lives, these vaccines could lead to complacency in countries tired of the foreclosure, said Michael Kinch, a drug development expert who is an assistant vice chancellor at the University of Washington in St Louis.
“I guess the day after someone is vaccinated, they’ll think,” I can get back to normal. Everything will be fine, “” he said. “They won’t necessarily realize that they might still be susceptible to the infection.”
COVID-19 is already thought to be spread by people without symptoms, and a vaccine that prevents symptoms can create an even higher number.
Vaccines are among the most effective weapons against infectious diseases and prevent up to 3 million deaths a year, according to the World Health Organization. Yet few, if any, are 100% effective in all the people who get them. For example, about 3% of people who get the measles vaccine develop a mild form of the disease and can pass it on to others.
130 shots
In their efforts to deal with a rapidly growing threat, developers are turning to technologies that have never been used successfully in humans. More than 130 shots are being prepared for the prevention of COVID-19, according to the World Health Organization.
Vaccines work by presenting the immune system with a form of germ – or a key part of it – preparing the body to react when actual exposure occurs. When this happens, immune proteins called antibodies glomer on the virus, interrupting its entry into cells. Sometimes vaccines increase immune T cells, which don’t do as much to prevent infections, but can slow and eventually stop their progression.
One common approach to raising antibody levels is to inject a virus that has been inactivated or killed. About nine of them are being tested: one, manufactured by the Chinese company Sinovac Biotech Ltd., has led to high levels of antibodies targeted by Covid in monkeys.
Another snapshot developed at the University of Oxford uses an innovative approach in which the Covid genes are inserted into a different and harmless virus. These make proteins recognized by the immune system, which raises defenses against a real infection.
About a quarter of the experimental shots taken by the WHO, including two already in human studies, follow the same approach as the Oxford vaccine. One of the advantages of the technology is its speed. AstraZeneca, which partners with Oxford, has announced that it will start delivering doses to the UK as early as September and will have doses to the United States, which helped fund development the following month. .
On Saturday, AstraZeneca and four European Union countries announced that they have reached an agreement to distribute hundreds of millions of doses of the vaccine. Beijing-based Sinovac Biotech also said over the weekend that test results for its human coronavirus vaccine support the advancement of studies in the final stages.
Antibody levels
It remains unclear how the vaccine developed by Oxford and AstraZeneca affects infections and infectivity. William Haseltine, a former HIV researcher at Harvard University, pointed out in a blog for Forbes that animals had roughly the same amount of viral genetic material, called RNA, in their systems, whether or not they received injections. Antibody levels against the virus were not as high as in highly protective vaccines, he said.
However, clinical signs of a severe infection, such as high respiratory rate and pneumonia, were better in vaccinated monkeys. It could still make such a move useful, according to Anthony Fauci, director of the National Institute of Allergies and Infectious Diseases.
“This vaccine doesn’t seem like a knockout to protect against infection, but it could be really good for protecting against disease,” Fauci told Stat Medical News website.
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The vaccine will be successful whether it prevents infections or serious symptoms, said Pascal Soriot, CEO of AstraZeneca, in an interview with the BBC. The vaccine’s progress toward advanced studies has been approved by an independent scientific group, and the company is waiting to see how it performs, said a spokesperson.
Fauci’s NIAID is partnering with Moderna Inc. on a Covid vaccine test whose main goal is to show that their vaccine prevents people from developing symptoms, the company said on June 11. Infection prevention is a secondary objective.
Effective preventive measures must also prevent transmission, said Dan Barouch, a researcher at the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center and Harvard University. Effective injections can allow some cells to become infected, but control the growth of the virus before it can be passed on to others, said Barouch, who is developing a vaccine with Johnson & Johnson. He said his efforts are aimed at a vaccine that prevents infections.
Prevent disease
The US Food and Drug Administration is considering options for a vaccine that prevents the disease.
“We would potentially consider an indication related to the prevention of serious illness, provided that the available data supports the benefits of vaccination,” FDA spokesperson Michael Felberbaum said in response to questions. “For licensing, we would not require that a vaccine protect against infection.”
Licensed vaccines, some of which against pertussis, have not been shown to protect against infection with the pathogen causing the disease, but have been shown to protect against symptomatic disease, said Felberbaum.
The idea of using imperfect vaccines and therapies is “good,” said Kinch. “It’s just on the practical side. And we can follow them with more perfect results. There will never be a really perfect vaccine.”
(With the exception of the title, this story was not edited by GalacticGaming staff and is published from a syndicated feed.)
