People who have survived COVID-19 may have some protection against re-infection, a new study suggests.
Scientists at Rockefeller University have found that a type of immunity, from memory B cells, lasts at least six months.
B cells ‘remember’ how to make antibodies against viruses, including the one that causes COVID-19.
And these cells are probably less easily misled by mutations in the peak protein of ‘supercovidous’ variants, such as the more contagious UK form, B117, compared to antibodies themselves.
The variant has now been found according to at least 17 US states, according to DailyMail.com.
At least four other variants have emerged on American soil, and others from South Africa and Brazil could fuel a daily boom in business – especially now that the Trump administration has lifted its travel ban.
Scientists are concerned that mutations to the peak protein that allows coronavirus to infect human cells will make variants less visible to antibodies from previous attacks with COVID-19 or vaccines.
But the B cells may help solve this problem, suggests the new research published in Nature on Monday.
Six months after developing COVID-19, 78 patients still had ‘memory’ coronavirus ‘B cells’ in their intestines (red, blue and green in the discs). These B cells could also produce neutralizing antibodies in other laboratory tests
This is because individual antibodies are very specific to the virus they first learned to fight.
But B cells’ developed ‘after patients’ recovery and’ expressed antibodies with increased neutralizing strength and width ‘, the researchers wrote.
When they tested specific antibodies against HIV viruses, they aimed to have mutant coronavirus nails on their surfaces, and the antibodies’ responses were striking and not the infectious nails in the laboratory.
But the B cells, which spent six months in patients’ bodies, not only recognized the disguised coronavirus, but also produced antibodies that could fight it.
Specific ‘memory B cells’ remain in the body and multiply rapidly, generating antibodies against the virus.
What’s more, they are more powerful than their original counterparts – and may be more resistant to mutations.
Infection in the past has been linked to an 83 percent lower risk of getting the virus compared to those who have never had it.
‘Neutralizing antibody activity decreases over time. But the number of memory B cells remains unchanged, ‘said author Michel Nussenzweig of Rockefeller University in New York.
“In addition, it may be more resistant to mutations in the vein protein of the virus that mediates cell entry.”
This has important implications for the vaccine program.
“Memory responses are responsible for protecting against reinfection and are essential for effective vaccination,” said Dr. Nussenzweig.
At least 105 axles of the British B117 ‘super-covid’ variant have been detected in 17 US states (red and pink) and at least three other variants have emerged
‘The observation that memory B cell responses do not expire after 6.2 months – but instead continue to develop – strongly suggests that infected individuals may respond quickly and effectively to the virus when re-exposed. . ‘
The findings are based on 87 Covid-19 patients aged 18 to 76 years whose blood samples were analyzed twice – one month and just over six months after diagnosis.
Professor Michel Nussenzweig said: ‘These observations show that memory B cells have the ability to develop in the presence of small amounts of persistent viral antigen – small proteins that can be detected by the immune system.
“The continued presence and evolution of memory B cells suggests that humans are rapidly becoming able to produce powerful virus-neutralizing antibodies after reinfection.”
This follows a study by Public Health England last week in which it was found that immunity lasted at least five months.
The human immune system responds to infection by producing antibodies that can specifically neutralize the infectious agent.
Prof Nussenzweig said: ‘Immunity can last at least six months. The levels of specific memory B cells remained constant during the study period.
“People who have been infected before can get a quick and effective response to their own exposure.”
Human antibodies to Covid-19 have been shown to protect against infection in animal models
Prof Nussenzweig added: ‘The levels of these antibodies may decrease over time.
“But memory B cells – as their name implies – ‘remember’ the infectious agent and can use the immune system to produce the same antibodies in re-infection. ‘
Evidence is growing that immunity is lasting longer than previously feared. But experts have warned that humans could catch Covid-19 again – and could infect others.
And officials stress that people should follow the home rules – whether they had the virus or not.
Prof Susan Hopkins, of Public Health England, says that it is particularly true that some of those who were re-infected had high levels of the virus, even without symptoms.
She said: “This means that even if you believe you have had and are protected from the disease, you can rest assured that you are highly unlikely to contract serious infections, but there is still a risk that you will.” can contract an infection and transmit it to others.
“Now, more than ever before, it’s important that we all stay home to protect our health care and save lives.”