Some people may have antibodies after catching the common cold that could also offer some level of protection against SARS-CoV-2 (the virus that causes COVID-19), a preliminary new study has found. And that seems to be particularly true for kids.
The study, published online in the journal Science last week, was essentially an accident. Researchers in London were working on developing new, more sensitive tests that screen for COVID-19 antibodies. The body produces antibodies, or proteins, in response to an infection — and they may provide some level of immunity moving forward, though it’s still unclear how long it may last with COVID-19.
In the course of checking how well their new tests were performing, researchers made the somewhat surprising discovery that some people appeared to have antibodies that react to COVID-19 even though they’d never had the virus.
The researchers then looked at 300 blood samples collected pre-pandemic, and found that nearly all of those individuals had antibodies that protect against coronaviruses that cause the common cold. (There are many different strains of coronaviruses, some of which cause the common cold.)
In addition, around 5% of the adults had antibodies that would “recognize” SARS-CoV-2 even if they hadn’t had a cold around the time their blood was drawn. And 7% of the adults who had recently come down with a cold had similar antibodies.
Perhaps even more striking: Nearly half of the children in the small study had antibodies that would recognize SARS-CoV-2.
“Our results show that children are much more likely to have these cross-reactive antibodies than adults,” study author Kevin Ng, a doctoral candidate at Francis Crick Institute in London, said in a press release.
“More research is needed to understand why this is,” he added, “but it could be down to children being more regularly exposed to other coronaviruses.”
Indeed, the Centers for Disease Control and Prevention says the common cold tends to be the main reason why children miss school — and it’s not unusual for them to come down with three or more colds in a typical year.
So it certainly would be welcome news to parents to learn that all of those days sneezing and sniffling may offer their children some level of protection against COVID-19. But experts who were not involved in the new study urge caution.
For one thing, just because antibodies “recognize” a virus does not mean they will necessarily fight that virus off.
“The pre-existing antibodies the investigators found in uninfected people reacted with the bit of SARS-CoV-2 spike protein called ‘S2,’” said Philippa Marrack, chair of the Department of Immunology and Genomic Medicine at National Jewish Health.
The “spike” protein is the part of the virus that sticks out and essentially what glues to human cells, Marrack explained. Antibodies against the “S2” part of that protein “are less likely to be useful,” she added, pointing to the staggering global impact of COVID-19 (51 million cases and counting) as evidence of the fact that most people don’t appear to have pre-existing antibodies that fully fight off the SARS-CoV-2 virus.
The researchers behind the small new study also cautioned against jumping to the conclusion that coming down with the common cold will protect against COVID-19 — though they do believe it may contribute to why some people, particularly children, get milder symptoms of the disease.
According to the American Academy of Pediatrics, which is tracking COVID-19 and children in roughly half of the United States — based on the data that is available — anywhere between 0.6% and 6.4% of kids who have been infected with the virus have required hospitalization. (Some states include young adults up to age 20 in their data.) Overall, the group states that severe illness among kids is “rare.”
Outside researchers like Marrack agree it’s worth continuing to investigate, though ultimately she believes that there are likely many factors that tend to make children less susceptible to severe illness from COVID-19.
“Antibodies that have been generated in response to other coronaviruses may help to some extent,” she said.
For now, the best defense against COVID-19 remains the same: regular hand washing, maintaining social distance and wearing a mask.
Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.