Pregnancy and H1N1 infection – Authors' reply
Authors: Denise J Jamieson, Margaret A Honein, Sonja A Rasmussen, Kitty F MacFarlane, Sonja J Olsen
Journal: The Lancet (2009)

We agree with Roberto Burioni and colleagues that novel treatment approaches for influenza virus infection such as use of anti-influenza monoclonal antibodies might hold promise and are certainly worth pursuing. However, most investigations have used animals, and treatment in human beings has mainly focused on the most severe cases. Treatment with anti-influenza virus antibodies has not yet been shown safe and effective for use in non-pregnant people.1Beigel J Bray M Current and future antiviral therapy of severe seasonal and avian influenza.Antiviral Res. 2008; 78: 91-102Crossref PubMed Scopus (218) Google Scholar It will probably be even longer before such treatment options would be considered for pregnant women since additional safety studies would need to be done, and pregnant women and their health-care providers might be reluctant to use new treatments, even if proven safe and effective. Therefore, it is important to promote a strategy of vaccination and basic hygienic prevention, and prompt antiviral treatment of pregnant women who develop influenza illness. Frequent hand washing, covering mouth and nose when coughing or sneezing, staying home and away from others when sick, and avoiding contact with people sick with influenza-like illness are basic steps that can help decrease the likelihood of influenza and other respiratory illnesses. Owing to the increased risk of severe disease and death, once influenza is suspected in a pregnant woman, appropriate antiviral therapy should be started promptly, ideally within 48 h when the benefit is expected to be the greatest. Although there are known side-effects of antiviral therapy, as pointed out by Burioni and colleagues, the benefits of antiviral therapy outweigh potential risks for pregnant women. We were pleased to learn of the experience in Singapore as reported by Lin Lin Su and colleagues. Singapore should be applauded for its remarkable achievement in providing antivirals to 28 pregnant women promptly, with a median of 2 days from symptom onset to receipt of antiviral drugs. We agree that experience with managing pregnant women during the outbreak of severe acute respiratory syndrome probably helped prepare them and others for this current influenza pandemic2Jamieson DJ Ellis JE Jernigan DB Treadwell TA Emerging infectious disease outbreaks: old lessons and new challenges for obstetrician-gynecologists.Am J Obstet Gynecol. 2006; 194: 1546-1555Summary Full Text Full Text PDF PubMed Scopus (29) Google Scholar and that there is much for us to learn from the experiences and successes of others. Finally, the very promising news about the 2009 pandemic influenza A (H1N1) monovalent vaccine3Clark TW Pareek M Hoschler K et al.Trial of influenza A (H1N1) 2009 monovalent MF59-adjuvanted vaccine—preliminary report.N Engl J Med. 2009; (published online Sept 10.)https://doi.org/10.1056/NEJMoa0907650Crossref Scopus (413) Google Scholar, 4Greenberg ME Lai MH Hartel GF et al.Response after one dose of a monovalent influenza A (H1N1) 2009 vaccine—preliminary report.N Engl J Med. 2009; (published online Sept 10.)https://doi.org/10.1056/NEJMoa0907413Crossref Scopus (452) Google Scholar highlights the potential role that vaccination efforts can have in preventing morbidity and mortality. It is essential that all pregnant women are encouraged to be vaccinated, as reflected in current US guidance that places pregnant women in a high-priority group for vaccination with 2009 H1N1 vaccine.5Centers for Disease Control and PreventionUse of influenza A (H1N1) 2009 monovalent vaccine: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2009.MMWR Recomm Rep. 2009; 58: 1-8Google Scholar The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. We declare that we have no conflicts of interest. Pregnancy and H1N1 infectionDenise Jamieson and colleagues (Aug 8, p 451)1 highlight the risk of infection with pandemic influenza A virus (H1N1) in pregnant women, documenting high rates of hospital admission and complications. Notably, six deaths in H1N1-infected pregnant women were reported between April 15 and June 16, 2009, in the USA. Full-Text PDF Pregnancy and H1N1 infectionDenise Jamieson and colleagues1 highlight high morbidity and mortality rates in pregnant women infected with the H1N1 influenza virus. Admission rates were 41% and the median time from symptom onset to receipt of antiviral therapy was 9 days. Could earlier initiation of antiviral treatment have resulted in a better outcome? Full-Text PDF