by Aria Bendix, Business Insider
Measures to curb the coronavirus’ spread, like mask wearing and social distancing, effectively blunted last year’s flu season: Just 155 Americans were hospitalized with the flu from October through January. That’s compared to around 8,600 during roughly the same time period a year prior.
But as Americans ditch their masks and return to normal activities, experts caution that respiratory infections could become more prevalent again.
“I do anticipate that in the months ahead, if people are not wearing masks — and we’ve started to see some of this already — that there will likely be an increase of upper respiratory infections in places that are not wearing masks,” Rochelle Walensky, director of the Centers for Disease Control and Prevention, said at a White House press briefing last week.
Common colds are particularly likely to spread, since they’re a year-round illness (though cold cases typically spike in the spring and winter).
“There’s no doubt the colds are coming back,” Dr. Monica Gandhi, an infectious disease expert at the University of California, San Francisco, told Insider.
In some instances, colds could be easily confused with a mild COVID-19 case. The following chart shows how COVID-19 symptoms either overlap with or diverge from symptoms commonly associated with colds, flu, and seasonal allergies:
The COVID Symptom Study — a project that tracks self-reported COVID-19 symptoms via an app — suggests that a headache and runny nose are now two leading indicators of a COVID-19 infection in the UK, especially among people who are young or partially vaccinated.
So public-health experts are considering whether the Delta variant — which is now dominant in the UK — is causing a somewhat different set of symptoms than the original strain. It’s also possible that average COVID-19 symptoms appear milder lately because more young, healthy people (who are less likely to be vaccinated) are getting infected — or getting official diagnoses — than earlier in the pandemic.
For the most part, though, fully vaccinated people rarely contract COVID-19, let alone develop symptoms. From January to April, just 0.01% of vaccinated Americans — around 10,000 out of 100 million people — got COVID-19 after they were fully immunized, according to a May CDC report. About 27% of those infections were asymptomatic.
That means severe respiratory symptoms among vaccinated people are more likely the result of something other than COVID-19, Gandhi said.
“There are more people hospitalized for other non-COVID respiratory pathogens in the UK right now than there are for COVID-19,” Gandhi added. “That’s what happens when you mass vaccinate.”