First Trial of H1N1 Vaccine for Pregnant Women to Begin This Week

From Medscape Medical News
Martha Kerr

September 10, 2009 — The first clinical trial of a 2009 influenza A (H1N1) candidate vaccine for pregnant women will launch this week, according to the National Institute of Allergy and Infectious Diseases (NIAID).

"Data indicate that pregnant women are at higher risk for complications from the 2009 H1N1 influenza virus . . . so this trial will provide critical information for public-health planning," NIAID director Anthony S. Fauci, MD, said in an NIAID announcement.

Centers for Disease Control and Prevention (CDC) figures show that 45 deaths from H1N1 influenza occurred between mid-April and mid-June of this year. Of these, 6 (13%) were in pregnant women. During the first month of the H1N1 influenza outbreak this year, pregnant women were 4 times more likely to be hospitalized with the flu than the general population.

"Women are at higher risk of developing severe illness if they become infected with influenza virus while pregnant, which is why they are strongly encouraged to receive the seasonal influenza vaccine every year," Dr. Fauci said.

The CDC's Advisory Committee on Immunization Practices has recommended that pregnant women be among the top-priority groups and receive the H1N1 vaccine as soon as one becomes available.

The trial will involve up to 120 pregnant women, aged 18 and 39 years, who are between 14 and 34 weeks' gestation.

Subjects will receive either 15 or 30 µg of a vaccine manufactured by Sanofi Pasteur. It will be administered in 2 doses, given 21 days apart, using the same trial design as that for the H1N1 vaccine that began in August.

The vaccine contains inactivated virus and has no thimerosal or adjuvant added.

Safety will be monitored continuously, as will immune response to the vaccine, including antibody production. Umbilical cord blood will be collected at delivery to assess the transfer of maternal antibodies to the infant.

The NIAID-funded national network of Vaccine and Treatment Evaluation Units (VTEUs) is conducting the trial at 6 sites: Baylor College of Medicine VTEU in Houston, Texas; Group Health Cooperative Center for Health Studies VTEU in Seattle, Washington; Saint Louis University VTEU, in Missouri; Vanderbilt University VTEU in Nashville, Tennessee; Duke University in Durham, North Carolina; and Scott and White Memorial Hospital and Clinic in Temple, Texas.

The NIAID is also planning to conduct trials in pregnant women of other candidate 2009 H1N1 influenza vaccines made by other manufacturers.

Detailed information about this study can be found on the ClinicalTrials.gov Web site.