You probably know at least one person who has avoided the virus even though he or she has many chances of becoming infected. 1 Some people have avoided Covid even though they have been exposed to itCredit: Alamy Or maybe you’re part of a club without Covid. This club is about 30 million strong, according to modeling from the University of Cambridge in February. They said about half of UK adults had not yet experienced the error for the first time, MailOnline reported. Many of us will be familiar with this scenario during the pandemic. a family member begins to experience the indicative signs of coronavirus, undergoes tests and returns a positive result. Others in the same house are knocked down. But there is a lucky soul who manages to avoid catching it completely. But why does this happen? Experts, including Richard Stanton, a professor of virology at Cardiff University School of Medicine, gave some explanations.
1. Genetics
Immunity varies from person to person, in part because of its genetic makeup. Professor Stanton said: “People have differences in how good their immune system is because they have different genes. “Some people’s immune systems are simply ‘better’ at fighting the virus.” A number of studies have linked genetics and immunity during the Covid crisis. For example, researchers at the University of Oxford have identified a piece of DNA that doubles the risk of death from Covid – and people from the South Asian heritage are more likely to carry it. The Imperial College London has found that fluctuations in the human immune system “make the difference at least whether you have a symptomatic illness or not”. Research focuses on different genes of human leukocyte antigen (HLA), with certain types of HLA being associated with a higher or lower risk of symptomatic Covid disease. Danny Altmann, professor of immunology at Imperial, said: “The key genes that control your immune response are called HLA genes. “For example, people with the HLA-DRB1 * 1302 gene are significantly more likely to have a symptomatic infection.” Another group theorized that people who look good have better immunity and are therefore less likely to have Covid by now.
2. Previous infections
The immunity created by a previous infection is not something you can measure. But it could be the reason why your friend has still avoided a period of Covid disease. Professor Stanton said: “It is possible that a previous infection with some common cold viruses could leave you with enough immune memory to handle Covid better.” Studies have shown that there is an intersection between protection from the common cold and protection from Covid. It would indicate that, even if someone is exposed to Covid and takes it, their immune system will neutralize it before it causes symptoms. Scientists at Imperial College London have found that the usual cough and sneezing boost vital white blood cells called T cells, which can recognize a number of viruses. Bug immunity has generally declined en masse due to lockdowns, so it is not clear how relevant this level of protection is.
3. Variations
We’ve seen a lot of Covid variations over the last two years – Alpha, Delta, Omicron and Beta to name a few. Some strains have biological advantages that make them easier to spread, even in households. By the same token, it can explain why the people you live with did not receive the error. “Omicron is more contagious than Delta, so we see that family members are more likely to become infected if someone in the household has Omicron compared to Delta,” said Professor Stanton. The current dominant strain, Omicron BA.2, has high rates of secondary attack, meaning it is more likely than previous variants to pass from person to person.
4. Opportunity
“Finally, it may be just random, based on the virus that the infected person has in their mouth and how often (and how closely) others interact with it,” said Professor Stanton. It is hard to believe that after two years, one was lucky enough to avoid Covid disease. However, there are many factors that will affect their chances. For example, someone who can work from home, live alone and shop for food online may be less likely to get Covid. While a front-line worker, such as in a store, care home or hospital, or someone who lives with many people, is much more likely to have had it.
5. Protection against vaccines
The vast majority of people have now been vaccinated against Covid (or two, or three, or four…). This will change the immunity of one person to another, as Covid antibodies are higher about three weeks after the dose. They start to weaken in the coming months, so annual reinforcement notches are expected for the rest of the year. Andrew Freedman, an infectious disease specialist at Cardiff University, told CNBC that the reasons why some people become infected with Covid and others are not “probably related to immunity to the vaccine, the previous infection or both.” He added: “We know that many people still have a (mostly mild) Omicron infection despite being fully vaccinated, including [having had] a booster. “However, the vaccine still reduces the chance of catching Omicron, and responses vary from person to person. “Some people catch it and others do not, despite the very important report.”
6. You actually had it
Many people dumbfounded by the fact that they did not have Covid often conclude that they had it, but showed no symptoms. About a third of people with the virus do not appear to have any signs. The test helps identify those who are “asymptomatic.” However, there is also the perception that people have different viral loads, which contributes to how much virus they shed. It seems that in people with low viral load – where the virus has not reproduced so dramatically in their body, resulting in fewer virus particles – PCR tests can give a false negative result. People who are vaccinated are much more likely to produce low viral loads and milder symptoms if they become infected.
Investigations
The so-called “never Covid” cortex has prompted scientists to conduct research. Infectious disease specialists around the world are examining why some people’s bodies seem to be naturally protected. Dr Rhia Kundu, lead author of the Imperial study, said: “Exposure to the SARS-CoV-2 virus does not always lead to infection and we were eager to understand why.” However, Dr. Kudu also warned that one should not rely on the idea that Covid is extremely immune if one does not already have it. He said: “On the contrary, the best way to protect yourself from Covid-19 is to get fully vaccinated, including your booster dose.” Covid vaccines have been shown to reduce serious infections, hospitalization and death and remain largely effective against known strains of the virus. Three doses have been shown to be the only effective way to prevent Omicron stain disease. However, the immunity of the vaccine decreases over time, which is why older and more vulnerable adults are invited to come for a spring boost.
