Safety and Immunogenicity of 2009 pH1N1 Vaccination in HIV-Infected Pregnant Women
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 (www.clinicaltrials.gov).
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ABSTRACT: Influenza poses unique risks to pregnant women, who are particularly susceptible to morbidity and mortality. Historically, pregnant women have been overrepresented among patients with severe illness and complications from influenza, and have been more likely to require hospitalization and intensive care unit admission. An increased risk of adverse outcomes is also present for fetuses/neonates born to women affected by influenza during pregnancy. These risks to mothers and babies have been observed during both nonpandemic and pandemic influenza seasons. During the H1N1 influenza pandemic of 2009-2010, pregnant women were more likely to be hospitalized or admitted to intensive care units, and were at higher risk of death compared to nonpregnant adults. Vaccination remains the most effective intervention to prevent severe illness, and antiviral medications are an important adjunct to ameliorate disease when it occurs. Unfortunately, despite national guidelines recommending universal vaccination for women who are pregnant during influenza season, actual vaccination rates do not achieve desired targets among pregnant women. Pregnant women are also sometimes reluctant to use antiviral medications during pregnancy. Some of the barriers to use of vaccines and medications during pregnancy are a lack of knowledge of recommendations and of safety data. By improving knowledge and understanding of influenza and vaccination recommendations, vaccine acceptance rates among pregnant women can be improved. Currently, the appropriate use of vaccination and antiviral medications is the best line of defense against influenza and its sequelae among pregnant women, and strategies to increase acceptance are crucial. This article will review the importance of influenza in pregnancy, and discuss vaccination and antiviral medications for pregnant women.International Journal of Women's Health 07/2014; 6:681-689. DOI:10.2147/IJWH.S47235