National Vaccine Advisory Committee

Report on 2009 H1N1 Vaccine Safety Risk Assessment

Approved by the National Vaccine Advisory Committee on January 20, 2010
Approved by the Assistant Secretary for Health on January 22, 2010

Background

The National Vaccine Advisory Committee (NVAC) established the H1N1 Vaccine Safety Risk Assessment Working Group (H1N1 VSRAWG) with the charge to conduct independent, rapid reviews of available safety monitoring data for the 2009 H1N1 influenza vaccines.  Since the Working Group was created it has met five times to review available data from the Federal vaccine safety monitoring systems listed in Table 1. Based on the discussions of H1N1 safety data reviewed available as of its meeting on January 4, 2010, it has provided the following assessment for NVAC’s consideration on January 20, 2009, via telephone conference call. 

Report

Since our last report, an additional 35,085,900 doses of inactivated H1N1 and 7,191,600 doses of live attenuated H1N1 vaccine have been distributed.  A total of 74,714,720 doses of inactivated H1N1 and 19,435,300 doses of live attenuated H1N1 vaccine have been distributed as of 12/25/2009.  Based on the data summarized in Table 1, the Working Group concluded that the data are adequate to assess the presence or absence of a signal.  Additionally, the Working Group concluded that the data do not favor a signal between the outcomes examined and the H1N1 vaccines. A signal is defined as an event that could be temporally occurring more often after vaccine receipt than anticipated by chance alone.  The evidence for this includes:

1. No serious adverse events (SAE) have been attributed to the H1N1 vaccines in the clinical trials to date.
2. Comparison of reporting in the Vaccine Adverse Event Reporting System (VAERS) of SAE after seasonal and other similar vaccines and H1N1 influenza vaccines generally show similar levels of SAE.
3. For those systems conducting rapid cycle analysis¹, the rates of adverse events for pre-specified outcomes are within expected values.

The size of the population captured under active surveillance for vaccine safety is still limited and some analysis are based on small number of events.   As more data are available through active surveillance, conclusions will be based on a larger accumulation of data.  Larger samples may be needed to detect rare adverse events. Finally, the data collected and analyses conducted across systems are not uniform, making a consistent interpretation difficult.  Thus, the Working Group recommends that the Federal government continue to monitor H1N1 vaccine safety as more doses are administered and captured under active surveillance and thus the body of evidence accumulates on the safety profile of H1N1 vaccines.

All recommendations of the NVAC are made to the Department’s Assistant Secretary for Health.  Thus, the recommendation on vaccine safety monitoring listed above will be formally transmitted to the Assistant Secretary for Health, who will review and consider it for potential implementation options to include communications with various components of the Department.

H1N1 Vaccine Safety Risk Assessment Working Group Membership:

Stephen Cantrill, Associate Professor of Emergency Medicine, University of Colorado

Vicky Debold, Director of Research and Patient Safety, National Vaccine Information Center

Kathryn Edwards, Professor of Pediatrics, Vanderbilt University

Theodore Eickhoff, Professor Emeritus, University of Colorado School of Medicine

Susan Ellenberg, Professor of Biostatistics, University of Pennsylvania

Marie McCormick*, NVAC member, Professor of Maternal and Child Health, Harvard School of Public Health, former Chair of the IOM Immunization Safety Review Committee

Laura Riley, Assistant Professor of Obstetrics, Gynecology and Reproductive Biology, Massachusetts General Hospital

Mark Sawyer, Professor of Clinical Pediatrics, University of California, San Diego

*Chair of the NVAC H1N1 Vaccine Safety Risk Assessment Working Group

References

1. Lieu TA, et al.  Real-time vaccine safety surveillance for the early detection of adverse events.  Med Care 2007; 45 (suppl2): S89-S95.