We haven’t heard much about superspreader events in the past year or so, mainly because we haven’t really been looking for them.
The United States defunded and scaled back its testing and contact tracing programs in early 2022, and in doing so, we lost track of just how widespread COVID is. But if you’ve been out and about, or heard stories from other people who’ve been out and about, it’s seems as though superspreading events after large gatherings like concerts, weddings and conferences are still very much a thing.
While superspreading events might not be as prominent as they were during the beginning of the pandemic, social gatherings can cause clusters of new infections, even among people who’ve been vaccinated or previously infected. However, thanks to the tools we now have prevent and treat COVID — namely, vaccines and therapies like Paxlovid — the vast majority of infections that do break out of super spreading events likely won’t be too severe.
“The decrease in the susceptibility of the population as a whole, increase in personal protective behaviors, and the lack of case reporting have caused superspreader events to both be less likely to occur and less likely to be reported,” Bailey Fosdick, an associate professor of biostatistics and informatics at the Colorado School of Public Health, told HuffPost.
Several factors contribute to superspreader events.
There are a mix of factors known to contribute to superspreader events, including the environment in which transmission occurs, how infectious people with COVID are and the variant at play.
Dr. Janet Jokela, a clinical professor and interim executive associate dean of the Carle Illinois College of Medicine, said the primary factor in superspreading events is often a contagious person who is unaware they’re even infected.
“Such ‘superspreaders’ may not have any symptoms, only minimal symptoms, or may be more obviously ill,” Jokela said.
As was the case in 2020: Some people shed a bit of virus for a couple days, whereas others shed a lot of virus for a longer period of time and run the risk of infecting a ton of people.
The recent mix of variants are better at replicating within our nasal cavities, and it’s widely believed that the better the virus is at making copies of itself, the more transmissible it is. Certain variants, like BQ.1.1, are becoming more and more skilled at evading our immunity, which could further increase the risk of getting infected even after vaccination or infection.
How well the virus is able to spread is also influenced by the environment. The coronavirus is especially adept at spreading in crowded indoor environments with little ventilation.
“Superspreader events primarily depend on the host, as well as features of the virus, the environment, those exposed — and probably a combination of all of these,” Jokela said.
What do superspreader events look like today?
Most people now have some immunity against COVID, whether that’s through getting vaccinated and boosted or being infected. Because of the high level of immunity in the population, we aren’t seeing as many superspreading events as we once did.
But superspreading events can and do still occur, even if we’re no longer tracking them. Elizabeth Carlton, an associate professor of environmental and occupational health at Colorado School of Public Health, said it’s entirely possible to have superspreading at social gatherings — especially when there are people without immunity who are most at risk for contracting the illness.
“The trick is we don’t have a magic wand to identify who those people without immunity are,” Carlton said.
But superspreading events can occur even when the crowd is largely immune. The immunity we gain after being vaccinated or infected isn’t bulletproof, and growing research shows that while the vaccines do a good job at preventing infections for a few months, their ability to reduce transmission wanes with time. This makes people vulnerable to contracting a breakthrough infection or reinfection.
Most people with immunity will be well protected against serious disease if they do get COVID, Jokela said. Even so, while we’re seeing less severe cases from superspreading events than we did in 2020, COVID is still a leading cause of death in the U.S., indicating that substantial transmission is still occurring. Not to mention the fact that there’s still a risk of long COVID if you’re infected ― even with a mild case.
We don’t know how prevalent superspreader events are.
Truth be told, we don’t really know how common superspreader events are because there’s so little testing. According to Jokela, many people test themselves at home, if they test at all, and those results aren’t reported to local public health departments.
“Even when superspreader events do occur, we probably do not hear about them as often due to at home testing and lack of testing,” Fosdick added.
If you were recently boosted or infected, know that you are most likely well protected against severe illness. And though vaccination doesn’t eliminate transmission, it does drastically reduce it, so your chances of getting infected from a gathering with superspreading potential are still lower than if you hadn’t been vaccinated at all.
“This may not prevent infection with the current variants, but it protects against serious illness: critically important,” Jokela said.
Lastly, the same measures that were encouraged earlier in the pandemic — pre-event testing, masking, avoiding crowded spaces and investing in air ventilation — still help curb transmission and prevent superspreading events from occurring. Those measures are still vitally important as we navigate this phase of the pandemic.
We may no longer know how prevalent superspreading events are, but we still know how to protect ourselves in situations that have the potential to cause a burst of new infections.
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.
