Francisco R. Velázquez, M.D.: Getting your flu shot is important every year. This year is no exception.

Fall is here, and this year there are fewer restrictions on our holiday gatherings. We can celebrate a bit more by following simple precautions. Vaccinations, wearing masks, hand-washing and avoiding large groups of people we don’t know will help.

It is also important to remember that October marks the beginning of the flu season, which runs through May of the following year. The 2020-21 flu season was unusual compared to other seasons. The number of cases was extremely low, and immunizations around the country and in Washington state were higher on average. We can also attribute some of the lack of transmission to the various protective measures in place during the season. There were fewer community and school activities, fewer gatherings, lots of hand-washing, great masking compliance and an overall sense of caution. All of these worked well for COVID-19 and worked equally well for the flu, the common cold, and a variety of other respiratory and enteric viruses.

Most experts believe the flu is transmitted by small droplets expelled when people who are infected cough, sneeze or talk. Perhaps less frequently, transmission also occurs by touching contaminated surfaces and then touching your eyes, mouth or nose. This year, we have more access and more opportunities for transmission, thus it is very important that we get our flu shot. Ideally, it is recommended to receive the flu vaccine before Halloween, but if that wasn’t possible, try to get it at least two weeks before Thanksgiving, as the holiday season will be cause for some additional activities for most of us.

Usually 3-11% of the U.S. population develops symptomatic flu. If we add those predicted to be asymptomatic, the estimated percentage is 5-20%. In addition, according to estimates from the Centers for Disease Control & Prevention (CDC), we had between 140,000-710,000 hospitalizations and 12,000-52,000 deaths annually during the 2010-20 flu seasons. Anyone can get the flu at any age. Some studies have found children younger than 18 can be symptomatic almost twice as often as those older than 65. However, we also know people over 65 are more likely to develop serious complications if they get sick. That is also true of people with chronic conditions such as asthma, diabetes and heart disease. Women who are pregnant and children younger than 5 years of age are also at a higher risk of complications. The good news is that there are several vaccines currently available for anyone older than 6 months of age.

Speaking of vaccines, a common question I hear is, “Why do I need an annual shot?” That is a very good question, and there two very good reasons. First, the immune response conferred by immunization for some infections, like the flu, decreases over time. In addition, viruses change constantly. Each year around springtime, entities such as the Food and Drug Administration’s Vaccines and Related Biological Products Advisory Committee meet to select the influenza viruses most appropriate for the composition of the upcoming flu season’s vaccine. The World Health Organization has a similar group that also meets around the same time. During the meeting of the VRBPAC committee, members review epidemiological data, the results of surveillance data and the characteristics of the most common influenza isolates to determine the viral strains that will need to be incorporated based on the type of vaccine. That process determines how the vaccines will be manufactured. Out of the four types of influenza viruses (A, B, C and D), human influenza A and B viruses cause the seasonal epidemic that we know as flu season. Usually, one influenza A and one or two influenza B viruses, depending on the type of vaccine, are included in the seasonal flu shot. If you check the FDA website, you can find the specific formulation of the various vaccines.

The good news, regardless of the strains, is that the flu vaccine works very well. Prevention is the best cure. Getting immunized and following simple infection control measures such as hand-washing, good etiquette when sneezing and coughing, and staying home when sick, will provide a significant level of protection for you and those around you during the flu season.

Francisco R. Velázquez, M.D., S.M., is the Spokane Regional Health District health officer.