It can be difficult to remember the winter before COVID-19 when a common cold may have been the only reason for staying home, away from others until symptoms resolved. But if you do recall being sick with a cold last year, it might have been a blessing in disguise. Researchers from Boston University recently found that patients who caught a cold caused by a coronavirus in the past five years and later contracted COVID-19 were less likely to suffer serious symptoms.
According to a recent Huffington Post Canada report, seasonal common colds caused by coronaviruses teach our bodies how to fight off similar infections, resulting in a reduced risk for infected patients to require intensive care, a ventilator, or to die from COVID-19.
The study not only offers some hope of milder symptoms for those who experienced a cold in recent years, but the research may also help identify patients at greater risk for developing serious complications as a result of infection from the novel coronavirus. The study used the medical records of 15,928 adult patients at Boston Medical Center who had been tested for the common cold coronavirus between May 18, 2015, and March 11, 2020. The study also included data from 1,812 patients who were hospitalized with COVID-19 between March 12 and June 12, 2020.
Researchers stress that having had a common cold does not provide immunity against COVID-19, but an infection could have the potential to lessen symptoms of the novel coronavirus. The study also helps to explain why a significant number of people infected with COVID-19 remain asymptomatic or experience mild symptoms while others become seriously ill.
Not all common colds are caused by a coronavirus; more than 200 viruses can cause a cold. There are four types of coronaviruses that cause upper respiratory tract infections. Rhinoviruses are the most common cause of colds, responsible for more than half of cold-like illness and upper respiratory tract infection.
With a greater understanding of how the body’s immune system responds to coronaviruses, researchers will be able to develop better and more potent vaccines, understand how patients will respond, and help shape herd immunity models. Read more about immune memory in COVID-19 and how it relates to disease severity by following this link to recent research published in the journal Science.