CDC Recommends Stronger Flu Shots for People 65 and Older This Season—Here’s Why

Seniors often bear the greatest burden during flu season, accounting for a majority of hospitalizations and deaths.

Fast Facts

• The Centers for Disease Control and Prevention (CDC) have advised a preference for adults aged 65 and above to opt for higher-dose or adjuvanted flu vaccinations in the current year. Among the trio of recommended influenza vaccines are the Fluzone High-Dose Quadrivalent, Flublok Quadrivalent, and Fluad Quadrivalent variants. Should these specific vaccines not be accessible during the vaccination period, older adults are still encouraged to consider receiving a standard-dose unadjuvanted flu shot.

For the inaugural occasion, federal health authorities are advising a preferential approach, urging individuals aged 65 and above to opt for higher-dose or adjuvanted flu vaccinations specifically for the 2022-2023 flu season.

According to a media statement released by the Centers for Disease Control and Prevention (CDC) in June, individuals in the 65 or older age group often shoulder the brunt of severe flu-related ailments, with a majority of flu-linked hospitalizations and fatalities being concentrated within this demographic. This vulnerability could be attributed to a potentially diminished immune response to vaccines in older adults compared to their younger counterparts.

Dr. José R. Romero, Director of CDC’s National Center for Immunization and Respiratory Diseases, highlighted the significance of these potentially more potent vaccines for those aged 65 and older. He underscored the importance of employing these vaccines due to the heightened risk of severe flu-associated illnesses, hospitalizations, and fatalities among this population.

Moreover, the suggested course of action is anticipated to play a role in reducing racial and ethnic disparities in the administration of high-dose flu vaccines. By enhancing the availability and accessibility of these vaccines to minority groups, Dr. Romero believes that the recommendations can contribute to narrowing such gaps.

Three Recommended Vaccines for Seniors

Drawing on guidance provided by the CDC’s Advisory Committee on Immunization Practices (ACIP), the CDC has taken a distinct step this year by introducing a “preferential recommendation” for one among three vaccine options tailored to individuals aged 65 or above.

Fluzone High-Dose Quadrivalent (HD-IIV4): This inactivated flu vaccine possesses fourfold the antigen content found in standard dose flu vaccines. The amplified antigen presence, crucial for bolstering the body’s defenses against the virus, aims to elicit a more robust immune response in older adults, consequently enhancing their protection.

Fluad Quadrivalent (aIIV4): This standard-dose, inactivated flu vaccine incorporates an adjuvant, an adjunct ingredient designed to stimulate a heightened immune reaction. Employing an adjuvant known as MF59, an oil-in-water emulsion of squalene oil, this vaccine augments the immune response.

Flublok Quadrivalent (RIV4): Utilizing advanced technology that bypasses the use of live flu virus or chicken eggs in production, this recombinant flu vaccine is synthetically engineered. It contains an augmented antigen dose as well.

While the CDC refrains from endorsing any of these favored vaccines over the others, it strongly encourages seniors to avail themselves of any of these three alternatives, as opposed to a conventional standard-dose unadjuvanted flu vaccine.

Regrettably, comprehensive evidence comparing the efficacy of high-dose and adjuvanted flu vaccines against confirmed flu cases across numerous flu seasons remains elusive. According to Mary Ann Kliethermes, PharmD, Director of Medication Safety and Quality at the American Society of Health-System Pharmacists Inc., the current research data does not consistently favor any one of the three influenza vaccines across various seasons. Consequently, the CDC’s current recommendations reflect this uncertainty.

In essence, following a thorough review of the available information, the CDC panel has determined that insufficient evidence exists to confidently designate one vaccine as superior to the others, as stated by Kliethermes.

Reasoning Behind the New Recommendations

The elderly population faces an elevated vulnerability to severe and potentially life-threatening complications resulting from influenza, in stark contrast to younger adults. Citing CDC data, it is evident that a striking proportion of flu-related fatalities, reaching up to 85%, and hospitalizations, encompassing up to 70%, transpire among individuals aged 65 years and older.

This susceptibility partly stems from the progressive weakening of our immune systems as we age. Diminished immune efficacy renders us not only more susceptible to illnesses, but it also diminishes the potency of vaccines designed to enhance our immune response. The CDC’s media statement elucidates that the prescription of these three vaccines for the 65-and-above age group originates from a comprehensive scrutiny of available research. This examination suggests that the high-dose or adjuvanted vaccines hold the potential for greater effectiveness within this demographic when contrasted with standard-dose unadjuvanted vaccines.

Specifically, a trivalent iteration of the Fluzone High-Dose vaccine exhibited a 24% superior efficacy in averting flu incidents among older adults compared to the standard-dose vaccine, as indicated by a 2014 study published in the New England Journal of Medicine. The CDC’s shared observational data also underscores that the trivalent Fluad adjuvanted vaccine yielded heightened protection against flu-related hospitalizations and visits to emergency departments among Medicare beneficiaries, surpassing unadjuvanted standard-dose vaccines. This vaccine also showcased positive outcomes among nursing home residents, notably reducing their vulnerability to hospitalization and pneumonia.

However, it’s important to note that no studies currently exist to compare the quadrivalent high-dose and adjuvanted vaccines with the standard-dose variant. In spite of their potentially elevated efficacy, the high-dose and adjuvanted vaccines may trigger more frequent side effects, both locally at the injection site and systemically, than their unadjuvanted standard-dose counterparts. This observation was highlighted by Kliethermes, who noted, “It is interesting to note in these studies patients have more side effects, injection site reactions, with the more potent vaccines.”

During these studies, the most prevalent side effects linked to both high-dose and adjuvanted vaccines included transient pain, redness at the injection site, headaches, muscle aches, and temporary malaise. Notably, these side effects were of mild nature and short-lived.

The strategic recommendation of these flu vaccines for elderly Americans aims to augment accessibility and encourage heightened vaccine adoption within this demographic for the imminent flu season. Kathleen Cameron, Senior Director of the Center for Healthy Aging at the National Council on Aging (NCOA), underscores the importance of adhering to these novel vaccine guidelines for those over 65. However, in instances where the high-dose or adjuvanted vaccines aren’t available at the time of vaccination, the standard-dose unadjuvanted vaccine remains a suitable alternative.

Cameron expressed optimism that these updated CDC vaccine recommendations for older adults will stimulate clinicians and vaccine providers to prioritize and administer these endorsed vaccines, fostering equitable accessibility beyond historical trends. This endeavor also aspires to extend vaccine availability to underserved communities.

In summation, the overarching objective this year is to ensure that all elderly individuals receive one of the highly recommended, more efficacious flu vaccines, according to Cameron.