Before you know it, fall will be here and with it, the inevitable start of flu season. But year-round, teams are collecting and studying influenza samples in over 129 countries around the globe. The most dangerous and contagious viral strains are then identified and incorporated into the United States flu vaccine formulation to help recipients stay one step ahead of a severe flu season.

Australia’s current winter season, which aligns with our summer, often provides an early glimpse into the strains expected to circulate in the U.S. This year, data from Down Under has been concerning, with a highly contagious flu mutation known as ‘Super-K’ contributing to a massive surge in Australian transmission and hospitalizations. The good news is that, although flu viruses continue to mutate and evolve, the current Super-K variant has been proactively included in the 2026-27 U.S. vaccine formulations.

As the American Lung Association states, “Vaccination is the best way to prevent flu and its potentially serious complications for almost everyone.” Older adults overwhelmingly fall into those most at risk of flu complications, particularly if unvaccinated. Nearly 85% of flu-related deaths and up to 70% of hospitalizations occur in the over-65 unvaccinated population. While it is still possible to contract the flu after vaccination, studies consistently show that vaccination reduces the risk of severe outcomes such as pneumonia, organ failure, hospitalization and death.

I am often asked if the flu vaccine can cause the flu. It takes about two weeks for full post-vaccination immunity to set in, so it is possible to catch the flu during that waiting period or to contract another significant respiratory virus, such as COVID-19 or RSV, which will be covered in future editions.

Influenza injections are composed of inactivated viruses, meaning they are biologically incapable of causing infection. Mild post-vaccination symptoms, such as fatigue or soreness, are actually positive signs that the immune system is mounting a protective response. Regardless of whether they were vaccinated or not, seniors experiencing flu symptoms or exposure to one or more infected contacts, such as during a nursing home outbreak, may immediately contact their healthcare provider for consideration of additional antiviral therapy to shorten the course and reduce symptoms and spread.

Antiviral agents, however, have limited efficacy and potential side effects, and are not a substitute for timely vaccination. (Important tip: For maximum benefit during an active flu case, antivirals are best prescribed during the first 48 hours of symptom onset.)

Although immunization start dates are subject to change, current flu season guidance for adults age 65 and older advises vaccination in September or October with one of the following preservative-free, FDA-approved options:

Fluzone High-Dose^®: The high-dose [HD] formulation is four times stronger than the standard-dose flu shot. Clinical studies have shown that HD elicits a stronger antibody response in older adults, with a reduction in flu-related hospitalizations and deaths.

FLUAD^®: This contains an adjuvant or booster ingredient that enhances the body’s immune response. It was specifically developed for older adults whose immune response may be weakened due to age, medications or underlying disease.

FLUBLOK^®: Created in the laboratory, this recombinant (i.e., genetically multi-sourced formula) bypasses the need for egg or virus cell cultivation. This technology has generated an alternative for individuals seeking an egg-free vaccine.

Fluzone HD and Fluad are both egg-based vaccines. However, updated instructions on egg allergies state that the amount of purified egg protein in each vaccine is inconsequential and no longer requires special precautions. The exception being that individuals who previously experienced a severe allergic reaction to an egg-based influenza vaccine would continue to opt for egg-free alternatives.

At present, the above three vaccines are all equally recommended for seniors. Side effects are generally mild and subside within 72 hours. Refer to the FDA website for updates and detailed information on each vaccine: www.fda.gov/vaccines-blood-biologics/vaccines. As always, consult with your healthcare provider regarding vaccine-related concerns and guidance.

Dr. Shor is a board-certified senior care manager with advanced expertise in geriatric medication therapy. She operates a senior care management practice in the Coachella Valley and can be reached at (760) 271.2284 or www.shorcaresuccessfulaging.com.

Sources: 1) https://www.fda.gov/flu/; 2) www.hhs.gov/immunization/diseases/flu/index.html3; 3) https://www.lung.org/lung-health-diseases/wellness/vaccines