This Group Is a Major Superspreader, According to Scientists

A new study in the Proceedings of the National Academy of Sciences found that adults with a high body mass index (BMI) and those from older age groups tend to spread the disease more than most other groups. David A. Edwards, Ph.D., founder and chief scientific officer of Sensory Cloud, Boston, and formerly professor of bioengineering at Harvard University, headed the group that ran the survey. He and his group wanted to look at people who specifically were not associated with crowded events of people.

Edwards said their major question was “What is causing some people to exhale many more respiratory droplets than other people?” He explained, “Part of your immune system is your mucus. So, when you lose that barrier function, there’s a weakening of the immune system. We think with all these factors ― [increasing] BMI, age, infection ― there’s a correlation between weakened immunity and more respiratory droplets.”

Judith A. O’Donnell, M.D., chief of the Division of Infectious Diseases, Penn Presbyterian Medical Center, Philadelphia, reviewed the Edwards data and commented to Medscape: “I think you have to take the data at face value — as you get older and have a higher BMI, these are two potential risk factors for being someone who can spread respiratory aerosols more efficiently.”

Researchers say that one way for the obese and the elderly to cut their risks of spreading the disease is through use of a nasal hygiene spray that “strengthens airway mucus and exerts antimicrobial properties.” However, experts are quick to add, this precaution does not in any way replace the need to wear masks. And the obese and elderly should definitely get vaccine shots as soon as possible, though some continue to refuse them. These are the states where the most people refuse the COVID-19 vaccine.

Public health officials have started to worry that another surge of COVID-19 infections could be on the way, just weeks after a steep decline. Among the reasons are new variants and the relatively slow pace of vaccination. Beyond that, however, they worry that Americans will begin to disregard the need to social distance, wear masks, and wash their hands. The fact that new categories of superspreaders have been identified should be a reminder that people are not safe in public places and that care in smaller groups is also critical. This trend could cause another surge in cases.

While superspreaders, superspreading events, and new variants threaten to worsen the pandemic, the goal for the American public remains herd immunity. This has been defined as a point at which 70% to 80% of the population has been infected or vaccinated. The estimate for when this may happen stills varies widely from two or three months from now until as late as the fall.