What to Know About the Surge in Summer Colds

With an unusual number of people getting the sniffles this summer, an expert explains how to tell the difference between COVID-19, a cold, and summer allergies.

People are accustomed to dealing with runny noses and scratchy throats in the fall and winter, but there’s been an unusual occurrence this summer: a surge in cases of the common cold. “We are seeing patients with the usual upper respiratory symptoms more common to winter: sore throat, congestion, runny nose, fever, body aches,” says Dr. Judy Tung, section chief of Adult Internal Medicine at NewYork-Presbyterian/Weill Cornell Medical Center.

The reason: After months of masking and social distancing, the loosening of such restrictions has also meant that common cold viruses are circulating again. “It definitely seems to correlate with a relaxation in infection-control measures,” says Dr. Tung. “I hear a lot, ‘I went to a dinner party and then I developed this …’ or ‘I went on vacation and …’”

Dr. Judy Tung, expert on how to treat yourself at home for COVID-19 and colds

Dr. Judy Tung

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.

“It is important to get tested if you have cold symptoms, even if you have been vaccinated — not because you are going to get gravely ill, but because you may inadvertently pass it along to someone who is unvaccinated and could get gravely ill.”

— Dr. Judy Tung

What are the biggest differences in symptoms between common colds, allergies, and COVID-19?
COVID is associated with loss of smell and taste or unusual tastes that are not common in uncomplicated colds. Sinus infections can do this, but regular colds typically don’t affect smell or taste to the degree we see in COVID-19. COVID-19 also causes more GI symptoms (nausea, bloating, diarrhea) than typical colds cause.

Allergies can really feel like a cold, down to the body aches when allergies are severe. Allergies do not produce fever and normally take many days of post-nasal dripping to cause a cough, whereas colds and COVID can move to coughing swiftly.

With the rise of the Delta variant, what is important to keep in mind when you come down with what seems to be an ordinary cold or allergy symptoms?
It is important to get tested if you have cold symptoms, even if you have been vaccinated — not because you are going to get gravely ill, but because you may inadvertently pass it along to someone who is unvaccinated and could get gravely ill.

Vaccination definitely protects people from severe COVID infection (preventing hospitalization and death) and probably protects them from mild or asymptomatic COVID infection. However, the Delta variant is highly infectious, and there is increasing evidence that while the vaccines are still proving to protect us against severe COVID, they are not as effective against stopping us from getting the Delta variant infection.

I recommend to my patients that they get tested for COVID-19 infection to be informed, so they can increase efforts to isolate, mask, and distance, especially from family or friends who are vulnerable.

What’s the best way to care for summer colds?
There is little difference in the way we care for summer and winter colds — drink fluids and get plenty of rest. One advantage of summer is that you can open windows to ensure that shared space is well ventilated, especially if there is a member in the household who is sick.