Safety and Immunogenicity of 2009 pH1N1 Vaccination in HIV-Infected Pregnant Women

Department of Pediatrics (Infectious Diseases), University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado, USA.
Clinical Infectious Diseases (Impact Factor: 9.42). 02/2013; 56(10). DOI: 10.1093/cid/cit057
Source: PubMed

ABSTRACT Background. HIV-infected, pregnant women may have particular vulnerability to 2009 pH1N1 infection. The safety and immunogenicity of pH1N1 vaccination in HIV-infected, pregnant women are unknown.Methods. HIV-infected women between 18-39 years old and 14-34 weeks gestation on antiretroviral therapy received two 30 mcg doses of unadjuvanted, inactivated pH1N1 vaccine 21 days apart. Hemagglutination inhibition titers were measured at entry, 21 days post-dose #1, and 10 and 21 days post-dose #2, and, in mothers and infants, at delivery and three and six months post-delivery.Results. No severe vaccine-related adverse events were observed among 127 subjects. At entry, 21% had seroprotective (≥1:40) titers. Seroprotection and seroresponse (≥4-fold rise) occurred in 73% and 66% post-dose #1 and 80% and 72% post-dose #2, respectively. Of women lacking seroprotection at entry, 66% attained seroprotective titers after dose #1 and 75% after dose #2. Seroprotective titers were present in 67% of mothers and 65% of infants at delivery (median 66 days post-dose #2), 60% of mothers and 26% of infants at three months post-delivery, and 59% of mothers and 12% of infants at six months post-delivery. Vaccine response was associated with maternal CD4%.Conclusions. Two 30 mcg doses of pH1N1 vaccine were moderately immunogenic in HIV-infected, pregnant women. No concerning vaccine-related safety signals were observed. Seroprotection persisted in most women post-partum. Efficient transplacental antibody transfer occurred, but seroprotection in infants waned rapidly. Vaccination to protect HIV-infected, pregnant women and their newborns from new influenza strains is feasible, but more immunogenic platforms should be evaluated.Clinical Trials Registration. NCT00992017 (

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