To The Editor—Due to the high burden of estimated annual deaths and hospitalizations associated with influenza epidemics in the United States [1, 2], annual influenza vaccination is recommended for persons aged ≥6 months, and for those who are at increased risk of influenza-related complications, including persons with human immunodeficiency virus (HIV) infections [3]. In 2011, we published data from the HIV Outpatient Study (HOPS), an open prospective HIV cohort study of HIV-infected outpatients seen in 9 well-established community-based private practices, public health clinics, and university-based clinics, describing annual rates of influenza vaccination among HIV-infected persons in care during influenza seasons from 1999 to 2008 [4]. We found that an average of 35% of HOPS participants received an influenza vaccination while under observation during the time period under investigation. This letter serves as an update to the previous analysis by including 5 years of additional data describing influenza vaccination rates among HOPS participants through 30 June 2013.

Among 6548 active patients (patients with at least 1 clinical encounter during the time period under investigation), 4788 were vaccinated at any time between 1 July 1999 and 30 June 2013. The annual vaccination rates ranged from a low of 26.4% to a high of 50.9% (average, 38.7%; linear regression trend P = .043; Figure 1) during the influenza seasons studied. The HOPS recorded the highest rate of vaccination during the 2009–2010 H1N1 influenza season, but that level was not sustained in subsequent seasons. Although we detected an overall temporal increase in influenza vaccination rates over the 14-year period, the observed rates continued to be consistently lower than published recommendations and below the goal of 70% set for Healthy People 2020 [3, 5], underscoring the need for improving adherence to guidelines for annual influenza vaccination for HIV-infected persons.