Older adults and patients with chronic conditions are more vulnerable to severe influenza disease.
There are several different types of vaccines used in adults for influenza in the US, including high-dose inactivated vaccines (HD-IIV) and live attenuated influenza vaccines (LAIV).
A team, led by Jessica R. Cataldi, MD, MSCS, Adult and Child Consortium for Health Outcomes Research and Delivery Science, University of Colorado Anschutz Medical Campus and Children’s Hospital Colorado, examined family physicians’ and general internal medicine physicians’ perceptions, knowledge, and practices for use of the 2 influenzas types during the 2016-2017 and 2018-2019 influenza seasons.
In the study, which was conducted between February-March 2017 and January-February 2019 via email and mail surveys from nationally representative samples of family physicians and general internal medicine physicians
Currently, HD-IIV is licensed for adults at least 65 years old, while recommendations for use of LAIV have changed several times in recent years.
The 2017 surveys assessed HD-IIV practices and LAIV knowledge and practices, while the 2019 surveys focused on the knowledge and perceptions of HD-IIV and knowledge and practices of LAIV.
The researchers had response rates of 67% (n = 620) in 2017 and 69% (n = 642) in 2019.
Overall, 76% of physicians found HD-IIV to be more effective than standard dose IIV in older patients, while 65% of those surveyed almost always or always recommended HD-IIV for adults at least 65 years old.
However, the researchers said some physicians incorrectly thought the Advisory Committee on Immunization Practices (ACIP) preferentially recommends HD-IIV for adults older than 65 with cardiopulmonary disease (38%) or immunosuppression (48%). In addition, 25% and 28% of respondents recommended HD-IIV for these groups, respectively.
The investigators found in 2017, 88% of respondents knew that ACIP recommended against using LAIV during the 2016-2017 influenza season, while 4% recommended LAIV to their patients.
For 2019, 63% of physician respondents knew that ACIP recommended that LAIV could be used during the 2018-2019 influenza season, while 8% of respondents recommended LAIV.
“Many physicians incorrectly thought ACIP had preferential recommendations for HD-IIV,” the authors wrote. “Physicians should be encouraged to use any available age-appropriate influenza vaccine to optimize influenza vaccination particularly among older adults and patients with chronic conditions who are more vulnerable to severe influenza disease.”
The Value of Vaccines
Adjuvanted trivalent flu vaccine appears to better-protect elderly patients in nursing homes from influenza outbreaks when compared to non-adjuvanted vaccines.
The US Centers for Disease Control and Prevention (CDC) estimates for the 2019-2020 influenza season showed that while only about 5% of influenza cases in the US occurred in a patient over the age of 65, that age cohort made up nearly half of the 404,646 hospitalizations for influenza. Those aged 65 and older comprised nearly two-thirds of the 21,909 estimated flu deaths in the US occurred in elderly patients (13,673 deaths).
The push to boost flu vaccinations in nursing homes is not only related to the high risk of death; it also is an important step because a high number of hospitalizations related to influenza could exacerbate the already stretched capacity of healthcare providers in the United States due to the pandemic.
The study, “Use of High-Dose Influenza and Live Attenuated Influenza Vaccines by US Primary Care Physicians,” was published online in the Journal of General Internal Medicine.