Safety of seasonal influenza and influenza A (H1N1) 2009 monovalent vaccines in pregnancy

Abstract

Inactivated influenza vaccines have been given to pregnant women since 1964. Since 2004, the Advisory Committee on Immunization Practices has recommended that pregnant women receive trivalent inactivated influenza vaccine at any time during pregnancy. Studies conducted before 2009 did not identify any safety concerns after trivalent inactivated influenza vaccine in mothers or their infants. During the 2009–2010 influenza A (H1N1) influenza vaccination program, several monitoring systems were established or enhanced to assess whether adverse events were associated with H1N1 2009 monovalent vaccines (2009 H1N1 influenza vaccines). Data from these systems did not identify any safety concerns in pregnant women who received 2009 H1N1 influenza vaccines or their infants. Although live attenuated influenza vaccines are not recommended in pregnant women, a small number of studies have not shown any safety concern among pregnant women or their infants who were inadvertently exposed to these vaccines. This review summarizes US and international safety data for influenza vaccines in pregnant women with an emphasis on 2009 H1N1 influenza vaccines.

Keywords::

• adverse events
• epidemiology
• H1N1 influenza
• influenza
• pregnancy
• surveillance
• vaccine safety

Acknowledgements

The authors thank the CDC’s Immunization Safety Office staff, whose dedicated efforts allowed this activity to be conducted.

Disclaimer

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the CDC.

Financial & competing interests disclosure

The authors have no relevant affiliation or financial involvement with any organization or entity with a financial interest or financial conflicts with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents reserved or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.