NEW YORK (CNN) – Immunity to COVID-19 infection persists for at least five months, researchers report – and possibly longer.
Although the report seems confusing and contradicts a similar British report this week, it is not. There is more than one wave of infection control in the human body.
The human body produces an army of immune compounds in response to infection and some people are at first overwhelming, dying quickly, while others form more slowly. Measurements that show weakened antibody responses in the first few months after infection may be this first – but there’s a second group that’s building its forces in the background.
The new report released Wednesday shows that 90% of those recovered from COVID-19 infection retain overall antibody responses.
“While some reports say that antibodies to this virus disappear rapidly, we’ve found the opposite – that more than 90% of people with mild or moderate illness produce an antibodies to this virus. The antibody response was strong enough to neutralize the virus and the response was sustained for months, “said Florian Krammer, immunization professor at Icahn School of Medicine in Mount Sinai, who led the team in a statement. Father.
“This is essential for effective vaccine development.”
The team looked at the antibody responses of more than 30,000 people who tested positive for COVID-19 at the Mount Sinai Health System from March to October. They characterized their antibody responses. is low, medium or high. More than 90% have medium to high levels of antibodies, or titer, to the virus’s mutant protein – the structure it uses to grapple with the cells it infects.
They then closely studied 121 patients who recovered and donated their plasma – every three months after they first appeared their symptoms and again five months later.
They saw some decrease in antibodies. But others persevered, they reported in Science.
Dr. Ania Wajnberg, director of the clinical division, said: “The antibody titres in the serum that we measured in individuals could initially be generated by cytoplasm, which act as the first response to the virus invades and fuses together to produce initial waves of antibodies whose strength will soon weaken. Antibody testing at Mount Sinai Hospital.
“The level of the sustained antibody we observed was then likely produced by long-lived plasma cells in the bone marrow. This is similar to what we see in other viruses and there is. the possibility of them being here to survive. We will continue to monitor this group over time to see if these levels remain as stable as we suspect they are and hopefully they will. “
Antibodies are not the only defense that the immune system gathers against infection, but they are an important first line of defense.
While this cannot provide conclusive evidence that these antibody reactions protect against reinfection, we do believe that they will most likely reduce reinfection rates.
–The study author
“While this cannot provide conclusive evidence that these antibody reactions protect against reinfection, we believe they will most likely reduce reinfection rates,” the team wrote.
COVID-19 has only been around for less than a year, so scientists are still learning about it. Some people have had COVID more than once, but those cases are extremely rare. The NPR reported the first case in the US where someone was re-infected earlier this month. It also reports on a handful of confirmed cases.
There is an obvious concern about this. It would be much better for eliminating the pandemic if people develop permanent immunity to the virus after an infection. And of course, immunity will be crucial for the vaccine to work properly.
It happens to other viruses. Measles is an example. An outbreak of measles usually gives someone lifetime immunity – an effect known as antiseptic immunity. The same was true for smallpox before the virus was killed in the 1970s by a global immunization campaign. And proper vaccination against measles and smallpox completely protects against infection.
But respiratory viruses like the flu are more complicated. People can get repeated flu, and flu vaccines usually provide only partial protection against serious infections and illness. In part, this is because the flu tends to mutate.
Coronavirus seems to be in the middle. They can cause the common cold, but since they are usually not lethal, they have not been thoroughly studied. Until COVID-19’s deadly cousin, SARS, appeared, little interest in coronavirus was found.
However, there is evidence that people can and do develop some immunity to coronavirus.
“We know from working with human coronaviruses that neutralizing antibodies are produced, and that these antibodies can last for many years and protect against reinfection,” Wajnberg and colleagues write. or reduces the disease, even when the individuals are re-infected.
It is not clear if and for how long and for how long a human infection with SARS-CoV-2 protects against reinfection.
–The study author
“It is unclear if SARS-CoV-2 infection in humans is protected from reinfection and for how long.”
The next important step, they said, would be to establish what is called the correlation of protection. These are compounds that can be measured in the blood to let doctors know if someone is immune – so there’s no need to wait to see if they get re-infected after one episode or after immunization. .
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