Use of High-Dose Influenza and Live Attenuated Influenza Vaccines by US Primary Care Physicians.

Background: Several different types of influenza vaccine are licensed for use in adults in the USA including high-dose inactivated influenza vaccine (HD-IIV) and live attenuated influenza vaccine (LAIV). HD-IIV is licensed for use in adults ≥ 65 years, and recommendations for use of LAIV have changed several times in recent years.

Objective: We sought to examine family physicians' (FPs) and general internal medicine physicians' (GIMs) perceptions, knowledge, and practices for use of HD-IIV and LAIV during the 2016-2017 and 2018-2019 influenza seasons.

Design: E-mail and mail surveys conducted February-March 2017, January-February 2019.

Participants: Nationally representative samples of FPs and GIMs.

Main Measures: Surveys assessed HD-IIV practices (2017), knowledge and perceptions (2019), and LAIV knowledge and practices (2017, 2019).

Key Results: Response rates were 67% (620/930) in 2017 and 69% (642/926) in 2019. Many physicians believed HD-IIV is more effective than standard dose IIV in patients ≥ 65 years (76%) and reported their patients ≥ 65 years believe they need HD-IIV (67%). Most respondents incorrectly thought ACIP preferentially recommends HD-IIV for adults ≥ 65 years (88%); 65% "almost always/always" recommended HD-IIV for adults ≥ 65 years. Some physicians incorrectly thought ACIP preferentially recommends HD-IIV for adults < 65 years with cardiopulmonary disease (38%) or immunosuppression (48%); some respondents recommended HD-IIV for these groups (25% and 28% respectively). In 2017, 88% of respondents knew that ACIP recommended against using LAIV during the 2016-2017 influenza season, and 4% recommended LAIV to patients. In 2019, 63% knew that ACIP recommended that LAIV could be used during the 2018-2019 influenza season, and 8% recommended LAIV.

Conclusions: Many physicians incorrectly thought ACIP had preferential recommendations for HD-IIV. 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.