Getting the Flu Shot: How Early is Too Early?

With October and the cold and flu season rapidly approaching, questions about getting the seasonal flu shot at the right time in the coronavirus era still linger among healthcare consumers and patients.

Local pharmacies appear to be more ready than ever in stocking flu vaccines in August and aggressively promote them through ad campaigns, word of mouth, and in-store signage. A New York Times article published on August 25 of this year suggested an urgency in the public health matter, by giving the title “When Should I Get a Flu Shot? Now.” but became updated to “Your Flu Shot Has Never Been More Important” on September 9 [1]. And with the Centers for Disease Control and Prevention (CDC) recommending “that people get a flu vaccine by the end of October” [2], there appear to be mixed answers on the best time to get the flu vaccine to prepare for the “Twindemic” and more uncertainty ahead.

This writing makes the case to support the CDC’s recommendation for getting the flu shot in October.
First of all, the flu virus is evolving such that vaccine manufacturers have to keep up with the viral makeup of the viral agent. In particular, the T-shaped projections on the surface of the flu virus pictured above is what changes and attaches to cells lining the nasal passages, throat, and deep within the lungs to replicate and cause an infection [3].

Due to the evolving nature of the flu virus, August may be a bit too early to get the flu shot assuming a six-month coverage period, which would provide immunity up to February [4]. September may be for those looking to beat the crowds potentially lining up to get the flu shot in October. With the six-month coverage in mind, the vaccine may “wear out” around March. In other words, today’s vaccine made up of inactivated flu viruses or proteins will not resemble the kinds of flu species that are circulating in March of 2021. So this brings the October as an optimal time for receiving a flu shot for protection through April when flu activity pretty much ends at that time [5].

After considering when to get the flu shot, one may wonder what kind of vaccine to get as pharmacies carry trivalent, quadrivalent, or high-dose vaccines. The “trivalent” means the vaccine stimulates immunity against three types of flu strains, the H1N1, H3N2, and the B strain, whereas the “quadrivalent” offers similar protection but also includes additional coverage against the B strain [6]. The high-dose vaccine is recommended for those above 65 years of age, which contains four times the ingredient that drives immunity against the flu, especially when the immune system becomes less effective with age.

In all, the best time to get the flu shot depends on your age and preferences for coverage. Remember, it takes two weeks after immunization for the immune system to develop antibodies needed for protection when potentially encountering the real virus. The older population would benefit waiting until October to get maximal protection in November, December, and January. This plan should also be supplemented by covering sneezes given that the flu spread by droplets and can become airborne, and handwashing after coming into contact with public touchpoints like handles, doorknobs, and tables (while also taking care not to wash too frequently that can dry out your hands – moderation is key). As always, stay prepared, and stay healthy and safe.


[1] de León, C. (2020, August 25). Your flu shot has never been more important. Retrieved from

[2] (2020). Influenza (Flu) – Who Needs a Flu Vaccine & When. Retrieved from

[3] (2019). Influenza (Flu). Retrieved from

[4] Brady, V. (2019). No, really, get a flu shot: frequently asked questions about the flu vaccine. Retrieved from

[5] Advisory Board. (2020). The 2019-2020 flu season has come to an end. See it, charted. Retrieved from

[6] Kalarikkal SM, Jaishankar GB. Influenza Vaccine. [Updated 2020 Jul 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from:

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