Efficacy of Influenza Vaccination in HIV-Infected Persons

Efficacy of Influenza Vaccination in HIV-Infected Persons

A Randomized, Double-Blind, Placebo-Controlled Trial

From U.S. Naval Medical Center, San Diego, California; University of Rochester, Rochester, New York; and Quest Diagnostics at Nichols Institute, San Juan Capistrano, California.

Abstract

Background: Although influenza vaccination is recommended in persons infected with HIV-1, its efficacy is unknown.

Objective: To assess the immunogenicity, efficacy, and risks associated with influenza vaccination in persons infected with HIV-1.

Design: Randomized, double-blind, placebo-controlled trial.

Setting: Outpatient military clinic.

Patients: 102 patients with HIV-1 infection.

Intervention: Influenza vaccine (n = 55) or saline placebo (n = 47).

Measurements: Influenza antibody titers, CD4⁺ cell counts, and plasma HIV-1 RNA levels at baseline, 1 month after immunization, and 3 months after immunization; viral cultures from persons presenting with respiratory illness; and respiratory symptom interview.

Results: Twenty-three placebo recipients (49%) and 16 vaccine recipients (29%) reported respiratory symptoms (P = 0.04). Ten placebo recipients but no vaccine recipients had laboratory-confirmed symptomatic influenza (P < 0.001) (protective efficacy, 100% [95% CI, 73% to 100%]). No effect on plasma HIV-1 RNA levels or CD4⁺ cell counts was noted.

Conclusion: Influenza vaccination is highly effective in HIV-1-infected persons and does not seem to be associated with substantial changes in viral load or CD4 cell count.

Article and Author Information

Acknowledgments: The authors thank Rita Rossetti for tireless assistance with patient enrollment and follow-up, Duane Samuelson for vaccine preparation and randomization, Greg Gray and R. Riffenburg for help with statistics, Rosalind Battaglia for performing the hemagglutination inhibition assays, and R. Levandowski for providing the vaccine component antigens for antibody testing.
Requests for Reprints: Clinical Research Department, U.S. Naval Medical Center San Diego, 34800 Bob Wilson Drive, Suite 5, San Diego, CA 92134-1005.
Current Author Addresses: Drs. Tasker and Wallace: Infectious Diseases Division, U.S. Naval Medical Center, San Diego, CA 92134-5000.
Dr. Treanor: University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642.
Dr. Paxton: Agouron Pharmaceuticals, Inc., 11095 Torreyanna Road, San Diego, CA 92121.