Sick season returning to normal patterns

After COVID disruptions, winter illnesses at traditional levels

So far, respiratory virus activity in San Diego County has been much more bearable than it was this time last year.

Local labs and medical providers reported 942 coronavirus, 425 flu and 297 respiratory syncytial virus cases to the public health department last week. Last year, the numbers were eye-poppingly higher: 3,441 coronavirus, 2,386 flu, 401 RSV, during the same week.

It’s the same pattern for flu-like symptoms reported by patients visiting local emergency departments. Last week, 4 percent had fevers, coughs and or sore throats compared to 10 percent one year ago.

This is what normal looks like, says Dr. Robert Schooley, infectious disease specialist at UC San Diego. Generally, the heaviest months of activity for respiratory viruses are in the winter. Last year’s early arrival had a lot to do with the years that came before.

“We had a couple of years of artificial suppression with everybody wearing masks (and limiting contact) for COVID, and that allowed the overall population immunity to the other respiratory viruses to decline a bit,” Schooley said. “That’s why we saw them pick up a little earlier and get going in the fall.

“Now we’ve seen a couple rounds with a more normal fraction of the population getting infected, so I think we’re moving back toward a more-traditional pattern.”

None of these threats are static, and the novel coronavirus that causes COVID-19 has continued to mutate even as it causes less severe illness. The latest wastewater analysis from SEARCH, a coalition of local research labs, indicates that a new variant of the virus called BA.2.86 made up 5 percent of circulating virus in San Diego’s largest wastewater district as of Nov. 13.

BA.2.86 has been said to be as big an evolutionary leap as the difference between the original Omicron variant and Delta, it’s predecessor. Does its arrival mean that we are in for a particularly rough winter on the COVID front?

Scripps Research immunologist

Kristian Andersen, whose work has delved deep into the complexities of the COVID pandemic in recent years, said in an email Wednesday that while it seems clear that 2.86 will become dominant and cause a steady rise in cases, they will most likely not be severe.

Will this end up being a severe flu season? It certainly could, and Schooley said that vaccination remains the key to staying out of the emergency room for those who are at the highest risk.

“I think everybody who has any respiratory risk factors or who is older should certainly get all three vaccines, RSV, influenza and COVID,” Schooley said. “In the case of influenza, we know that vaccination decreases a little bit the likelihood of getting infected, but it decreases a lot the likelihood of being severely ill.