Skip Navigation
  • Text Size: A A A
  • Print
  • Email
  • Facebook
  • Tweet
  • Share

National Vaccine Advisory Committee

Report on 2009 H1N1 Vaccine Safety Risk Assessment

Approved by the National Vaccine Advisory Committee on February 26, 2010
Approved by the Assistant Secretary for Health on March 1, 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 seven times to review available data from the Federal vaccine safety monitoring systems listed in Table 1. Based on the review and discussion of H1N1 safety data available as of its meeting on February 8, 2010, it has provided the following assessment for NVAC’s consideration on February 26, 2010, via telephone conference call. 

Report

Since our last report, an additional 25,641,000 doses of inactivated H1N1 and 1,983,200 doses of live attenuated H1N1 vaccine have been distributed.  A total of 100,355,720 doses of inactivated H1N1 and 21,418,500 doses of live attenuated H1N1 vaccine have been distributed as of January 22, 201.  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.

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, although the data collected and analyses conducted across systems are not uniform, making a consistent interpretation difficult, there has been some progress in implementing more uniform definitions that should reduce these difficulties in the future. 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 the body of evidence accumulates on the safety profile of H1N1 vaccines and to continue work towards harmonizing surveillance approaches. The VSRAWG has been pleased with the thoughtfulness and thoroughness with which the Federal agencies have examined their data, and with their responsiveness to additional requests for data and analyses from VSRAWG members.

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

Table 1: Number of Persons Exposed to H1N1 Vaccine in Monitoring Systems Reviewed by the H1N1 VSRAWG

Vaccine Safety Program

Outcomes Monitored

Population Monitored

H1N1 MIV1 Exposures Captured in System

H1N1 LAMV2 Exposures Captured in System

Total H1N1 Vaccine Exposures Captured in System

Current as of

Analyses

Results

H1N1 Vaccine Trials

All health events

10,852

10,352a

500a

10,852a

01/25/10

Adjudication and analysis of SAE

No SAE related to vaccine

Vaccine Adverse Event Reporting System (VAERS)

All health events

US Population

100,355,720b

21,418,500b

121,774,220b

01/22/10

Comparison of reports for H1N1 versus seasonal influenza vaccines

SAE reporting after H1N1 are comparable to seasonal influenza immunization

Data-mining with comparison to similar vaccines

No signal

Vaccine Safety Datalink (VSD)

Pre-specified outcomes

9.5 million

997,557a

245,335a

1,242,892a

01/31/10

Rapid cycle analysis

No signal

 

 

Real-Time Immunization Monitoring System (RTIMS)

 

 

All health events

 

 

US Population

 

 

-

 

 

-

 

 

9,231a

 

 

01/31/10

 

 

Symptoms that trigger an alert

 

 

Cases being validated

Defense Medical Surveillance System (DMSS)

Pre-specified outcomes

1.4 million

958,769a

56,132a

1,014,901a

01/22/10

Rapid cycle analysis

No signal

Veteran’s Affairs (VA) Databases

1.Enhanced VAERS

 

2.Signal Detection

All health events

1.2 million

589,386b

-

589,386b

01/25/10

Comparison of reports for H1N1 versus seasonal influenza vaccines

No signal

Pre-specified outcomes

918,000

83,538a

-

83,538a

01/23/10

Rapid cycle analysis

No signal

Centers for Mediare and Medicaid Services (CMS)

Guillain-Barré syndrome

38 million

-

-

1,746,924a

02/01/10

Rapid cycle analysis

No signal

Indian Health Service (IHS)

Pre-specified outcomes

1.4 million

164,487a

43,401a

216,642a

01/30/10

Rapid cycle analysis

No signal

Post-Licensure Rapid Immunization Monitoring System (PRISM)

Pre-specified outcomes

30 million (17 million registry enhanced)

835,605a

8,476a

844,081a

01/16/10

Rapid cycle analysis

No signal

Guillain-Barré syndrome (GBS) enhanced surveillance

Guillain-Barré syndrome

45 million

-

-

-

-

-

 

*Vaccines and Medications in Pregnancy Surveillance System (VAMPSS)

Maternal and fetal outcomes

3,100

-

-

-

-

-

-

1H1N1 monovalent inactivated vaccine

2H1N1 live attenuated monovalent vaccine

*Data not yet available

aExposed to vaccine;bDoses of vaccine distributed