Influenza Vaccine Immunogenic in HIV+ Pregnant Women
Also provides protection against influenza in HIV-uninfected women, infants not exposed to HIV
THURSDAY, Sept. 4, 2014 (HealthDay News) -- The trivalent inactivated influenza vaccine (IIV3) provides protection against confirmed influenza in HIV-uninfected and HIV-infected pregnant women and in infants not exposed to HIV up to 24 weeks after birth, according to a study published in the Sept. 4 issue of the New England Journal of Medicine.
Shabir A. Madhi, M.D., Ph.D., from the Chris Hani-Baragwanath Hospital in Bertsham, South Africa, and colleagues conducted double-blind, randomized, placebo-controlled trials of IIV3 in pregnant women, of whom 194 were infected with HIV and 2,116 were not infected. Pregnant women and their infants were evaluated until 24 weeks after birth.
The researchers found that at one month after vaccination, in both cohorts, the seroconversion rates and the proportion of participants with hemagglutination inhibition (HAI) titers of ≥1:40 were higher among IIV3 recipients, compared to placebo recipients. Higher HAI titers were also seen in newborns of IIV3 recipients, versus newborns of placebo recipients. Among both HIV-uninfected placebo recipients and their infants, the attack rate for reverse-transcriptase-polymerase-chain-reaction-confirmed influenza was 3.6 percent. Among HIV-uninfected IIV3 recipients and their infants, the attack rates were 1.8 and 1.9 percent, respectively, yielding vaccine-efficacy rates of 50.4 and 48.8 percent, respectively. The attack rate for HIV-infected placebo recipients was 17.0 percent, while the rate for HIV-infected IIV3 recipients was 7.0 percent, yielding a vaccine-efficacy rate for these IIV3 recipients of 57.7 percent. Vaccination was found to be effective in HIV-unexposed infants up until 24 weeks after birth.
"Influenza vaccine was immunogenic in HIV-uninfected and HIV-infected pregnant women and provided partial protection against confirmed influenza in both groups of women and in infants who were not exposed to HIV," the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.