Will coronavirus infections acquire long-term immunity? The professor is optimistic

One of the biggest questions remains whether vaccination or coronavirus infection provide more lasting protection against covid-19, the expert points out. He considers it good news that immunology is at least beginning to suggest clearer facts.

“To understand if immunity is possible – and why it is questioned at all – it is important to take into account the nature of the (virus) SARS-CoV-2“The professor continues. She explains that it is a beta coronavirus, and many beta coronaviruses are already widely circulated in humans, the most well – known form of which is the common cold.

Immunity to the common cold is not long-lasting, which leads many scientists to question whether longer-term immunity to the SARS-CoV-2 virus is possible, the author of the comment outlines. He notes that studies of other nearby beta coronaviruses that cause SARS and MERS provide a glimmer of hope, as immunity is more persistent for these viruses and may be the case for the covid-19 virus.

Trained protection

The first immune cells to respond to the infection attack foreign substances and try to control the infection and reduce damage, Cruickshank said. He adds that immune cells that react later and are responsible for immunity are called B and T lymphocytes, taking time to learn to identify the threat they face, but once they acquire this ability, they can quickly detect and destroy the virus.

T and B lymphocytes work together to fight infection, but in reality they have very different functions that allow them to deal with a wide range of threats, the expert states. He explains that B cells produce antibodies that neutralize infection, while T cells become helper and cytotoxic – they directly kill viruses and their infected cells, while the former support B cells and cytotoxic T cells, collectively referred to as effector cells. .

“Studies have now shown the key role that these effector cells play in the fight against covid-19“The professor continues. She points out that if the infection is destroyed, these cells will die so that they do not cause extensive damage to the body.

However, some effector cells survive, and preliminary research, which has yet to undergo a scientific review procedure, has recorded their presence in the human body even six months after infection with the SARS-CoV-2 virus, the expert states. He adds that in the same way, people who underwent a mild form of covid-19 did not notice antibodies until nine months later, but they are gradually decreasing in the body, so they will definitely disappear once and for all.

Memorized danger

According to the author of the commentary, these findings arouse optimism about protection against re-infection. “But what happens if, or only eventually, the level of effector lymphocytes falls?Cruickshank asks. She replies that the human immune system knows another “trick” that protects us in the long run – once lymphocytes learn to deal with the virus, some cells remember it for the future and these memory cells can intervene quickly. if the threat reappears.

Memory cells are an extremely powerful tool in the human immune system and survive for a very long time, in the case of measles at least 60 years after vaccination, in the case of Spanish flu even 90 years after the pandemic, the scientist emphasizes. He points out that if we are to assess the possibility of long-term immunity against covid-19, not only effector cells can be taken into account, but all types of memory cells – B lymphocytes and both types of T lymphocytes.

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The advantage is that memory cells can be identified by their specific structure and proteins on their surface, which allows scientists to distinguish them from effector cells, the professor outlines. He recalls that covid-19 has been spreading for a year, so researchers have the opportunity to make great leaps in understanding the memory response to the disease.

It turns out that memory T lymphocytes are present in the body even in the range of six to nine months after infection, and the last preliminary, as yet unreviewed studies also found memory B lymphocytes, the author of the commentary declares. He adds that studies are also being conducted on whether encounters with the virus provide protection, with research from the second wave in Britain showing that healthcare professionals previously exposed to coronavirus were either completely immune or re-infected asymptomatically.

“Such observational studies give real hope about the permanence and potential of protective immunity“Cruickshank writes. However, she admits that we still have a lot to find out about immunity to covid-19, although research is advancing rapidly and strengthening our chances of beating the virus. The human immune system is extremely strong and scientific studies showing The expert claims that they give us the certainty that there is a real chance to “win the war with the covid-19”, for example with the help of vaccinations.