By Umaima Arif | Contributor
The common cold is certainly not the most pleasant of experiences. Neither, for the matter, is COVID-19, the disease that has plunged the global population into an ongoing pandemic today. However, a recent research study suggests that individuals who have experienced the common cold at least once in their lifetime may possibly harbor an undetermined degree of immunity from COVID-19.
Memory B cells are immune cells that produce antibodies to detect, target and destroy pathogens with the aim of clearing infection and preventing further manifestations of the disease. Memory B cells may last for decades or even a lifetime; as a result, the body can repeatedly generate immune responses it has used before in the case that the same pathogens re-infect the body.
Infectious disease experts at the University of Rochester Medical Center (URMC) were the first to discover that SARS-CoV-2 (the virus which causes COVID-19) induces the activation of these memory B cells.
The study compared blood samples from 26 people who were currently recovering from mild to moderate cases of COVID-19 and 21 healthy donors who have experienced another form of respiratory infection at least once before and whose samples were collected six to ten years ago, far before their first exposure to COVID-19. For each of these blood samples, the levels of memory B cells were measured along with their subsequent antibodies.
According to the observations of Mark Sangster, the Lead Study Author and PhD and Research Professor of Microbiology and Immunology at URMC, the blood samples of individual patients who had recovered from other respiratory infections and who were currently recovering from COVID-19 demonstrated a “pre-existing pool of memory B cells” that recognized SARS-Cov-2 and produced antibodies to attack it.
Furthermore, the study’s findings confirmed this cross-reactivity for specifically betacoronaviruses, which are a genus of the family Coronaviridae that includes SARS-CoV-2, SARS-CoV (which causes SARS), MERS-CoV (which causes MERS), and four other viruses that cause the common cold.
This means that memory B cells used to fight off the common cold can possibly constitute effective, long-term immune defenses against more severe respiratory infections, including COVID-19.
However, the level of protection these memory B cells can offer and the clinical implications for patient outcomes is still unknown. Researchers have yet to discover if pre-existing memory B cells can correlate with milder presentations of symptoms and shorter disease courses. Investigating this may even provide crucial information on whether memory B cells can be used to increase the effectiveness of vaccines against COVID-19