Why do some people get covid and others don’t: One of the major mysteries of the Covid-19 epidemic — and one that infectious disease experts are still looking into — is why some people get Covid and others don’t while being equally exposed to the virus.
Many of us know entire families that contracted Covid and were forced to isolate during the pandemic, but there are also numerous instances of couples, families, and coworkers who contracted the virus — but not everyone.
Indeed, according to studies, the chances of becoming infected within a household once one case is positive are “not as high as you’d imagine,” according to Danny Altmann, professor of immunology at Imperial College London.
‘Never Covid’ people
The reasons why some people never seem to obtain Covid — the so-called never Covid cohort — are the subject of an increasing amount of research.
People with larger numbers of T cells (a type of immune cell) from common cold coronaviruses were less likely to become infected with SARS-CoV-2, the virus that causes Covid-19, according to new research released last month by Imperial College London.
“Being exposed to the SARS-CoV-2 virus doesn’t always result in infection, and we’ve been anxious to understand why,” said Dr. Rhia Kundu of Imperial College’s National Heart and Lung Institute.
“We discovered that large amounts of pre-existing T cells, which are produced by the body when infected with other human coronaviruses like the common cold,” she said.
Kundu, on the other hand, issued a warning: “While this is a significant development, it is simply one method of protection, and no one should rely only on it. Instead, getting fully vaccinated, including your booster dose, is the best way to protect yourself against Covid-19.”
“There’s great curiosity in these examples of so-called ‘never Covids’ – persons who have definitely been exposed to close contacts in their household who are infected, but who are resistant to infection,” Lawrence Young, a professor of molecular oncology at Warwick University, told CNBC on Wednesday.
Early evidence suggests that these people had naturally acquired immunity from previous infections with common cold coronaviruses, according to him. “Why some individuals maintain levels of cross-reactive immunity is unknown,” he said, “but around 20% of common cold illnesses are caused to common cold coronaviruses.”
In addition to earlier exposure to coronaviruses — a vast family of viruses that can cause illnesses ranging from the common cold to more serious diseases or infections — one’s Covid vaccination status is likely to play a role in whether some people are more susceptible to Covid than others.
Vaccines and their Function
Covid immunization is now widely used in most Western countries, albeit there are differences in how and when the coronavirus vaccine is given to different populations.
In many countries, booster doses are also frequently used, and younger children are vaccinated, as governments strive to protect as many people as possible from the more transmissible but less clinically severe omicron variety.