Summary Safety Review - Havrix (hepatitis A vaccine, inactivated) - Assessing the Potential Risk of Decreased Amounts of Blood Platelets (thrombocytopenia)
October 27, 2016
Havrix (hepatitis A vaccine, inactivated)
Potential Safety Issue
Decreased amounts of platelets (cell fragments in blood involved with clotting)
- Havrix is a vaccine used to protect against hepatitis A virus infection.
- Health Canada reviewed a potential link between vaccination with Havrix and the development of thrombocytopenia after receiving a report of a patient developing a low platelet count following vaccination with Havrix.
- The review did not find an increased risk of thrombocytopenia with Havrix. Health Canada will continue to monitor the safety of Havrix.
Health Canada and the Public Health Agency of Canada continuously monitor the safety of all vaccines, including Havrix. After receiving a report of a patient developing a low platelet count following vaccination with Havrix, Health Canada reviewed a potential link between vaccination with Havrix and the development of thrombocytopenia. As a part of this review, Health Canada evaluated cases of thrombocytopenia provided by the manufacturer, cases reported to the Canada Vigilance Program
Use in Canada
- Havrix is a vaccine used to protect against hepatitis A virus infection in people at risk of coming into contact with the hepatitis A virus.
- Havrix has been sold in Canada since 1994, and is currently approved in 108 countries.
- An estimated 2.8 to 5.7 million Canadians have been vaccinated, and approximately 160 to 320 million people have been vaccinated world-wide.
Safety Review Findings
- At the time of the review, only 1 case of thrombocytopenia following vaccination with Havrix had been reported to the Canada Vigilance Program
Footnote1. Three other cases were also reported to the Canadian Adverse Events Following Immunization Surveillance System (CAEFISS).
- No confirmed cases of thrombocytopenia were reported in clinical trials before the marketing of Havrix. From 1992 until 2015, the manufacturer received 99 international reports of thrombocytopenia. It was not possible to determine if there was a link between Havrix and thrombocytopenia for either the Canadian or international cases because the cases were either not confirmed as thrombocytopenia, there were other possible causes of thrombocytopenia, or there was not enough information provided for assessment.
- The number of cases of thrombocytopenia following vaccination with Havrix reported internationally and in Canada, is much lower than the number expected in the general population.
- No association between the hepatitis A vaccine and thrombocytopenia has been reported in the literature.
Conclusions and Actions
- Health Canada’s review did not identify a link between vaccination with Havrix and thrombocytopenia following a review of the available data.
- Health Canada will continue to monitor the side effect information involving Havrix, as it does for all health products on the Canadian market, to identify and assess potential harms. Health Canada will take appropriate and timely action if and when any new health risks are identified.
The analysis that contributed to this safety review included scientific and medical literature, Canadian and international adverse reaction reports and what is known about the use of this vaccine both in Canada and internationally.
For additional information, contact the Marketed Health Products Directorate.
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