No, Recovering From a Cold Won't Protect You From COVID-19

Your yearly cases of the common cold won't do much good in protecting you from COVID-19. A new study has found that previously having one of the seasonal coronaviruses, which cause the common cold, does not help your body develop antibodies against SARS-CoV-2, the virus that causes COVID-19.

The study, which was published on February 9 in the journal Cell, analyzed blood samples from nearly 700 people that were banked before the pandemic began. The researchers found that more than 20% of those samples carried coronavirus antibodies that could bind to both: coronaviruses that can cause the common cold and key sites on SARS-CoV-2.

But, while the antibodies could attach to SARS-CoV-2, they did not neutralize the virus and weren’t associated with better outcomes in people who eventually contracted COVID-19.

The Findings

There are several different types of coronaviruses known to infect humans, and they range in severity. Four types—229E, NL63, OC43, and HKU1—typically cause mild to moderate upper respiratory tract infections, like the common cold. These viruses are known to cause symptoms like runny nose, sore throat, headache, fever, and cough.

Most people become infected with at least one of these coronaviruses at some point in their lives. However, there are other forms of coronaviruses that can cause severe disease, including SARS-CoV-2, MERS, and SARS.

The study featured individuals, both children and adults, who tested positive for COVID-19, and those who didn't. In their tests, researchers found that most of the samples contained antibodies to seasonal coronaviruses and, of those, 20% contained antibodies that were cross-reactive with SARS-CoV-2. Meaning, the antibodies would bind to sites on the spike protein or other areas of the virus.

In the group of individuals who did develop COVID-19, researchers did not find a difference between the infected and uninfected groups, suggesting that the antibodies did not offer protection against SARS-CoV-2.   

Researchers also tested 27 people who were hospitalized with COVID-19 and found that the levels of cross-reactive antibodies were boosted during the illness.

Their findings help debunk the theory that past encounters with the common cold may be a reason why some people with COVID-19 experience mild symptoms or no symptoms at all, while others become severely ill.

Why Common Cold Antibodies Won't Help

Previous research has suggested that the common cold may offer some level of protection against SARS-COV-2. One study published in the Journal of Clinical Investigation analyzed blood samples taken before the pandemic and found that, while antibodies to coronaviruses that cause the common cold didn’t prevent people from getting infected with SARS-CoV-2, those who had a previous coronavirus infection were more likely to develop “less severe” cases of COVID-19.

A study published in the journal Science that examined 302 adults and 48 children found that 5% of adults and 43% of children had coronavirus antibodies that reacted against certain proteins created by SARS-CoV-2. “The immunological mechanisms underlying this preexisting reactivity are not clear, but previous exposure to widely circulating common cold coronaviruses might be involved,” the researchers wrote.

Some viruses can offer protection against viruses in the same family, but it's not a guarantee, William Schaffner, MD, an infectious disease specialist and professor at the Vanderbilt University School of Medicine in Tennessee, tells Verywell. "It depends on the virus," he says.

Mark Hicar, MD, PhD, associate professor of infectious disease at the University at Buffalo in New York, agrees. "Sometimes they are not very protective," he tells Verywell. "For example, for influenza strains from year to year, although there are enough differences to support changing the specific strains in the vaccine, studies show that a history of prior immunizations offers some protection on its own." He also points out that antibodies from people infected with SARS can "neutralize" the SARS-CoV-2 virus.

Cross-reactive antibodies can be common, Lewis Nelson, MD, chair of the department of emergency medicine at Rutgers New Jersey Medical School, tells Verywell. "In fact, the history of vaccines started when it was noted that milkmaids exposed to cowpox did not get smallpox," he says.

In the case of the common cold and COVID-19 the spike proteins on the outside of coronaviruses are "overall similar looking," Hicar says. However, he adds, "the specific portions that bind the receptors on our body to allow them to infect cells are relatively unique. So, the common cold coronaviruses don’t look enough like SARS-COV-2 at the specific area that binds the receptor on the human cells that allow infection."

While research on the topic is ongoing, Schaffner says that most experts do not think the common cold can help with COVID-19. "It's been the majority opinion of virologists and immunologists that our normal human coronaviruses don't protect against COVID-19," he says.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.