SAN DIEGO – Past research has shown that patients with HIV infection vaccinated early in the flu season are generally more likely to contract influenza or influenza-like illness (ILI), compared with those receiving late vaccination.
The reason likely is that antibody titers wane over time, especially among individuals with HIV infection, according to a study published in HIV Medicine, which noted that it is less clear, however, if the timing of influenza vaccination within the flu season affects the probability of an infection later during that season.1
To help answer that question, a study team led by VA San Diego Healthcare System researchers sought to determine if there is a relationship between the timing of influenza vaccination and incidence of influenza or influenza-like illness (ILI) in patients with HIV infection.
To do that, they conducted a retrospective cohort study of HIV-infected patients in care at the VA San Diego Healthcare System from Sept. 1, 2005, to May 31, 2013. Results indicate that patients who received influenza vaccine early in the season were more likely to contract influenza or ILI than patients who were vaccinated late, and vaccinated patients who developed influenza or ILI were more likely to do so later in the season.
“HIV-infected patients vaccinated early in the flu season were more likely to contract influenza or ILI than those vaccinated later in the season,” study authors concluded.
- Glinka, E., Smith, D. and Johns, S. (2016), Timing Matters – Influenza Vaccination to HIV-Infected Patients. HIV Medicine. doi: 10.1111/hiv.12360