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: 8.89). 02/2013; 56(10). DOI: 10.1093/cid/cit057
Source: PubMed


Pregnant women infected with human immunodeficiency virus (HIV) may have particular vulnerability to 2009 pandemic H1N1 influenza (pH1N1) infection. The safety and immunogenicity of pH1N1 vaccination in HIV-infected pregnant women are unknown.

HIV-infected women 18-39 years of age and 14-34 weeks' gestation on antiretroviral therapy received two 30-μg doses of unadjuvanted, inactivated pH1N1 vaccine 21 days apart. Hemagglutination inhibition titers were measured at entry, 21 days after dose 1, and 10 and 21 days after dose 2, and, in mothers and infants, at delivery and 3 and 6 months postdelivery.

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% after dose 1 and 80% and 72% after dose 2, respectively. Of women lacking seroprotection at entry, 66% attained seroprotection 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 after dose 2), 60% of mothers and 26% of infants at 3 months postdelivery, and 59% of mothers and 12% of infants at 6 months postdelivery.

Two 30-μg doses were moderately immunogenic in HIV-infected pregnant women. No concerning vaccine-related safety signals were observed. Seroprotection persisted in most women postpartum. 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.

1 Follower
14 Reads
  • Source
    • "Immunogenicity and efficacy data from the 2009–2010 influenza A (H1N1) pandemic were very similar among pregnant women when compared to seasonal influenza vaccination. Seroprotective titers were observed in populations of both HIV-negative and HIV-positive women who were vaccinated during pregnancy.45,46 In a cohort of 120 women, 89% also had seroprotective titers in cord blood at delivery, confirming transplacental transfer of antibody.45 "
    [Show abstract] [Hide abstract]
    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(1):681-689. DOI:10.2147/IJWH.S47235
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Influenza vaccination during pregnancy is the primary intervention to protect pregnant women, their fetus and infant from influenza infection. The World Health Organization recommends that countries expanding or initiating influenza immunization programs should consider pregnant women as the highest priority group. However, it is considered to be an expensive public health measure and data on the effectiveness and safety of the vaccine has been lacking and inconsistent. Evidence of the vaccine’s effectiveness and safety is critical to the decision making process of governments and policy-makers, as well as clinicians and pregnant women.
    JBI Database of Systematic Reviews and Implementation Reports 07/2014; 12(6):251 -381. DOI:10.11124/jbisrir-2014-1269
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The current approach to protecting pregnant women from influenza infection and serious influenza-related complications is vaccination. It is, therefore, critical to evaluate the vaccine's safety, immunogenicity, and protection efficacy during pregnancy. However, because it is affected by previous influenza vaccination or infection, the efficacy of the seasonal trivalent inactivated influenza vaccine is difficult to evaluate in pregnant women. The A/H1N1pdm pandemic in 2009 provided us with the opportunity to evaluate the immunogenicity of the influenza vaccine unaffected by previous vaccinations or infections. Vaccination with inactivated influenza virus during pregnancy elicited neutralizing antibody titers that were sufficient and comparable to those of naturally infected individuals. Furthermore, post-pandemic surveys provided a wealth of definitive information on vaccine efficacy and safety. In addition, transplacental transfer of antibodies following vaccination protected newborn infants against influenza infection. With reports showing the effectiveness of influenza vaccine during pregnancy, it is suggested that influenza vaccination benefits both mothers and their young infants. Copyright © 2015 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
    Journal of Infection and Chemotherapy 02/2015; 21(4). DOI:10.1016/j.jiac.2015.01.015 · 1.49 Impact Factor
Show more