Hindsight is 20/20: Recent reports for RSV, flu, and COVID-19
By Karen Kier
Pharmacist on behalf of the ONU HealthWise team
The expression “hindsight is 20/20” is attributed to American humorist Richard Armour from an article in The Van Nuys News. The California newspaper was published on February 17, 1949. The term refers to the Snellen vision chart testing for visual acuity. The term is used to express a clearer vision of events after they have occurred.
Vaccines can sometimes fit this category when we wonder how effective they may be in preventing or reducing disease. We are entering the fall/winter phase of flu, RSV, and COVID-19. September, October and November can be ideal months to consider getting vaccinated.
Last flu season saw the emergence of a pretty nasty strain of influenza. The H3N2 subclade K mutation spread rapidly and caused a more severe form of the flu. The symptoms remained similar and included fever, cough, sore throat, body aches, headache, and chills. The H3N2 subclade K virus was responsible for a higher rate of hospitalization and death from the flu in 2025-2026.
The 2026-2027 flu shots for this season all contain an H3N2 subclade K strain for improved protection. Actually, this year’s flu shots have all new strains for both the A and B subtypes. The egg-based flu vaccine contains subtype A H1N1 Missouri, subtype A H3N2 subclade K Darwin, and subtype B Tokyo Victoria lineage. The cell-based flu vaccine differs in the subtype B as the Pennsylvania strain from the Victoria lineage. The new mRNA flu vaccine (mFlusiva®) has the same H1N1 subtype, but the subtype A H3N2 subclade K is a Michigan strain from the Darwin lineage and the subtype B is the Pennsylvania strain.
It is highly encouraged for those 6 months and older to get a flu vaccine this season.
A new program allows the nasal flu vaccine (FluMist®) to be given at home through the FluMist® Home delivery program (www.flumist.com). FluMist® is a live attenuated vaccine and is only recommended for those ages 2 through 49 years. It can not be given to anyone with a suppressed immune system. You go to the website and answer medical questions and if you qualify, they will mail you the flu vaccine nasal spray for a $8.99 shipping and handling fee. The package is temperature controlled to maintain effectiveness. Ohio law allows home administration of FluMist® when sent from the company.
For those over 65 years of age, the recommendation is to receive the flu vaccine considered to provide higher antibody response and this includes Fluzone® High-Dose, Flublok®, and Fluad®.
For those over the age of 50 years, you may consider the new mRNA flu vaccine as an option. Study data in over 70,000 participants showed superior efficacy in preventing laboratory-confirmed flu when compared to the traditional flu vaccine. The mRNA flu vaccine was reported to be 26.6% more effective. In the 65-year-and-older group, the mRNA vaccine displayed a superior antibody response to traditional flu shots. Interestingly, the rate of side effects was similar between the mRNA vaccine and the traditional vaccine. Some individuals have had a concern due to side effects with the mRNA COVID-19 vaccine. It is important to note the difference with less side effects of the mRNA flu vaccine. Moderna has the only FDA-approved mRNA for the flu, but GSK has entered into research for their flu mRNA vaccine with clinical trials starting this fall.
The RSV vaccine is for those 60 years of age and older and for those 50 years and older with risk factors for an increase in RSV infections, including lung disease and a suppressed immune system. The RSV vaccine is a one-and-done shot and should not be repeated unless advised by a healthcare professional.
On May 28, 2026, the FDA announced that the COVID-19 vaccines needed to be updated with the SARS-CoV-2 JN.1-lineage XFG for the monovalent vaccines. This provides the best match for the current circulating COVID-19 viruses. The fall COVID-19 vaccines are in the process of being shipped to pharmacies and healthcare facilities in the next week. The 2026-2027 COVID-19 vaccines provide a different strain with better protection from infection.
On September 2, 2026, the Journal of the American Medical Association (JAMA) released special communications on the effectiveness and safety of the 2026-2027 flu, RSV and COVID-19 vaccines. A systematic review of 69 studies for the influenza vaccine showed a significant reduction in severe disease and hospitalizations, especially in older adults, infants, and children. For the RSV vaccine, the systematic review evaluated 75 studies and reported a reduced risk of severe RSV and hospitalizations in older adults, with a lower side effect profile than had previously been reported related to blood clots. In evaluating the COVID-19 systematic review, the authors evaluated 155 studies and concluded the vaccine for COVID-19 “consistently reduces the risk of hospitalizations” for those at high risk, including infants and pregnant women.
The JAMA studies provide good 20/20 hindsight for the value of vaccines in flu, RSV and COVID-19. Talk to your pharmacist or healthcare professional for the best time and type of vaccine for you or your family members.