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Studies have found that immunity to coronavirus lasts for several months



Researchers report that immunity to Covid-19 infection has lasted for at least five months, and possibly longer.



A man and a woman looking at her cell phone: Perth, Australia, April 20: Registered nurse Heather Hoppe at Charles Geldner in Perth, Australia on April 20, 2020 The trial clinic at the Jazz Hospital receives flu vaccination. Health care workers in Western Australia are participating in a new trial to test whether the existing tuberculosis vaccine can help reduce their chance of contracting COVID-19. Frontline staff from Fiona Stanley, Sir Charles Gairdner and Perth Children’s Hospital in 2000 are participating in a research trial that will see half of the participants receive the existing Bacille Calmette-Guerin (BCG) vaccine in addition to the flu vaccine. The other half gets regular flu shots.  The BCG vaccine was originally developed to fight tuberculosis, but it is hoped that it can help reduce the chance of contracting the coronavirus, reduce the severity of symptoms and enhance immunity in the long term.  The BRACE trial was conducted by the Murdoch Children's Institute.  (Photo by Paul Kane/Getty Images)


©Paul Kane/Getty Images AsiaPac/Getty Images
Perth, Australia-April 20: Registered nurse Heather Hope receives flu vaccination at the trial clinic at Sir Charles Geldner Hospital on April 20, 2020 in Perth, Australia. Health care workers in Western Australia are participating in a new trial to test whether the existing tuberculosis vaccine can help reduce their chance of contracting COVID-19. Frontline staff from Fiona Stanley, Sir Charles Gairdner and Perth Children’s Hospital in 2000 are participating in a research trial that will see half of the participants receive the existing Bacille Calmette-Guerin (BCG) vaccine in addition to the flu vaccine. The other half gets flu shots regularly. The BCG vaccine was originally developed to fight tuberculosis, but it is hoped that it can help reduce the chance of contracting the coronavirus, reduce the severity of symptoms and enhance immunity in the long term. The BRACE trial was conducted by the Murdoch Children’s Institute. (Photo by Paul Kane/Getty Images)

Although the report seems to be confused and contradictory with a similar report issued this week in the UK, it is not the case. People’s body will produce a lot of immune compounds due to infection, some of which will be overwhelming at first and then die quickly, while others will slowly build up.

A new report released on Wednesday shows that 90% of people recovering from Covid-19 infection maintain a stable antibody response.

“Although there are reports that antibodies against this virus disappear quickly, we found that the situation is just the opposite-more than 90% of patients with mild or moderate disease have an antibody response sufficient to neutralize the virus, and this response can be maintained for many reasons. Months.

“This is essential for effective vaccine development.”

The team studied the antibody response of more than 30,000 people who tested positive for Covid-19 in the Mount Sinai Health System between March and October. They rated the antibody response as low, medium or high. More than 90% of people have moderate to high levels or titers of antibodies to the virus’s spike protein-this structure is used to catch infected cells.

Then, they carefully studied 121 patients who recovered and donated plasma-once three months after the first symptoms, and again after five months.

They did see a decline in certain antibodies. But they persevered, and they published an article in the journal Science.

“The serum antibody titers that we initially measured in individuals may be produced by plasmablasts, which are the first responding cells to the invading virus and gather together to produce initial antibodies whose strength quickly disappears,” clinical director Ania Wajnberg Said the doctor. Antibody test at Mount Sinai Hospital.

“The sustained antibody levels we subsequently observed were probably produced by the long-lived plasma cells in the bone marrow. This is similar to what we have seen in other viruses, and may mean that they will continue to exist. We will continue to focus on this group. Let’s see if these levels remain stable as we hope.”

Antibodies are not the only means of protection for the immune system against infection, but they are an important first line of defense.

The research team wrote: “Although this does not provide conclusive evidence that these antibody responses can prevent reinfection, we believe that they are likely to reduce the chance of reinfection.”

Covid-19 has only been around for less than a year, so scientists are still learning about it. People have been infected more than once, most of them are anecdotes, and they are far apart.

There are obvious concerns about this. If people have permanent immunity to the virus after infection, it would be better to eliminate the pandemic. And, of course, immunity is essential for the vaccine to work properly.

It happens with other viruses. Measles is an example. A measles usually makes someone immune for life-this effect is called bactericidal immunity. The same is true for smallpox, before the global vaccination campaign eliminated the virus in the 1970s. The correct measles and smallpox vaccination can completely prevent infection.

But respiratory viruses such as flu are trickier. People may get flu over and over again, and flu vaccines usually only provide partial protection against infections and serious diseases. Part of the reason is that flu is prone to mutation.

The coronavirus seems to be somewhere in between. They cause the common cold, but because they are usually not fatal, they have not been fully studied. Before the emergence of the deadly cousin of Covid-19, SARS, there was little interest in the coronavirus.

Nevertheless, there is evidence that people can and do develop immunity to the coronavirus.

Wajnberg and colleagues wrote: “We learned from our collaboration with common human coronaviruses that neutralizing antibodies can be induced, and even if the individual is re-infected, these antibodies can last for several years and provide protection against reinfection or relief. Disease protection.”

“It is unclear whether human infection with SARS-CoV-2 can prevent reinfection and how long it will last.”

They said that the next important step will be to establish a so-called protection link. These are compounds that can be measured in the blood, and they can tell the doctor if someone is immune-so there is no need to wait to see if they get infected again after an attack or a vaccine.

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