Summer cold symptoms come at a time when summer allergy season is also in full swing and with cases of COVID-19 on the rise due to the Delta variant taking hold. To understand what viruses are circulating now and how to tell the difference between a summer cold, allergies, and COVID-19, Health Matters spoke with Dr. Tung, who is also associate dean for faculty development at Weill Cornell Medicine.
Health Matters: Is there a surge in common colds? When did it start?
Dr. Tung: Yes, there has been a surge of upper respiratory infections since March. There are a number of reasons for this, including a relaxation of infection control measures (reopening, unmasking, less social distancing) that has allowed a return of viral circulation.
In fact, the CDC issued an advisory in June when they detected an increase in respiratory syncytial virus (RSV) infections in the South after a long lull of less than typical levels of exposure to RSV from May 2020 to March 2021. We also saw very little flu last year.
The rise feels steeper because of the relative dearth of respiratory infections when infection-control measures were tightly in place. Also, because of our COVID-19 awareness, every sniffle catches our attention now, whereas pre-pandemic, many upper respiratory infections went unnoticed, so people didn’t necessarily seek medical care.
What cold viruses are currently circulating?
We’re seeing an increase in the usual cold viruses, including rhinovirus, coronavirus (not SARS-CoV-2), adenovirus, parainfluenza, and enterovirus. And yes, all are creeping up.
Why are we usually able to avoid bad colds in the summer? Why are colds lasting longer?
One theory for why colds are lasting longer this summer is that the immune system got a little forgetful, not having been exposed to the most current viral strains, and therefore is less prepared to fight them off. The immune system builds antibodies and other memory white blood cells to fight off pathogens after being exposed to them. When our immune systems are exposed to cold viruses all year long, they are “on the ready.” That didn’t happen last year because of all the precautions people took to protect themselves against COVID.