Calendars had barely been flipped to September when signs started popping up at pharmacies, supermarkets and medical offices across the Spokane area: “Flu shots now available!”
It is indeed the season for flu vaccinations, and an updated coronavirus shot is due to arrive soon (clearance from a CDC advisory committee is expected Tuesday). So what makes September so important for vaccinating against seasonal respiratory diseases? One factor is that it takes about two weeks for a flu shot to ramp up immune response to its maximum levels.
“The reason for that is so your body has time build that immunity,” said Dr. Francisco Velazquez, Spokane Regional Health Officer. “And as we get into the colder months, we spend more time in indoors and we…do see some of those respiratory illnesses distribute themselves among the community.”
That’s why Dr. Velazquez says the ideal time to get your vaccinations is between Labor Day and Halloween. That goes for people who got vaccinated last year, too, because flu strains change over time. Flu season happens first in the Southern Hemisphere, providing doctors and public health officials north of the Equator a preview of the most commonly circulating strains.
“We have enough data that helped us determine what are the flu strains that we need to be thinking about,” Velazquez said. “The flu vaccine is realigned every year…to make sure we’re providing people the protection that is important.”
Getting a flu vaccine this year is important, Velazquez said, because respiratory diseases have become more common since the relaxing of Covid protocols and safety steps. The winter of 2022-23 was proof, when flu and Respiratory Syncytial Virus (RSV) cases in Washington and Idaho rose to levels not seen since before the pandemic.
“We saw a significant increase in not only the flu, but RSV, in children and adults that we hadn’t seen in previous years,” Velazquez said.
In May, the Washington Department of Health said 262 people in the state died from the flu during the 2022-23 season, the highest death toll in five years. The department also said flu vaccinations reduced juvenile hospitalizations by 75 percent and adult hospitalizations by nearly half – though the department also noted fewer people got flu vaccinations, especially among children and pregnant women.
Seventy-two Idahoans died from the flu in the 2022-23 season. The highest total among the state’s seven public health districts – sixteen deaths – happened in the Panhandle region.
Another respiratory threat is coronavirus, especially for the unvaccinated and senior citizens. Like the flu vaccine, Covid shots this season are tailored to fight the most recent common strains.
“Even if you’ve had a previous Covid vaccine, the virus mutates. And as the virus mutates we need to get protection for some of the newer strains, which is what this vaccine does,” Velazquez said.
Velazquez said immunization is especially recommended for people who are very young or very old, or immunocompromised people. But he was quick to add that healthy, young to middle-aged people should get the updated shots as well.
“As we know, immunity waxes and wanes. So it goes down over time,” Velazquez said. “And now we’re being faced with newer members of the omicron family. If you want to have the most updated level of protection, ideally, it would be a good conversation to have with your provider now as to whether you should get the updated vaccine in the very near future.”
Washington has seen a slight uptick in new coronavirus cases since late July, and wastewater sampling in Spokane shows a similar rise that began in late June. But neither increase is anywhere near the severity seen in previous Covid spikes.
The current omicron subvariants in Washington (designated “XBB” lineages) are more easily transmitted among people, Velazquez said, but produce clinically mild symptoms in people without pre-existing conditions.
The same qualities that help spread flu virus particles in the colder months – closer quarters with people, more time indoors – also make it more likely we’ll continue to see Covid cases this winter, Velazquez said. People who are interested can get a Covid shot at the same time they get a flu vaccination, so both injections have a chance to get the body’s immune system revved up before the peak of respiratory virus transmission.
