Abstract
Influenza vaccine is recommended to prevent influenza-related morbidity and mortality. Post-marketing surveillance of adverse events following influenza vaccine is essential to monitor vaccine safety, inform immunization program planning and evaluation, and build confidence in immunization. To summarize adverse events following immunization (AEFIs) reported after receipt of influenza vaccines administered within the Universal Influenza Immunization Program in Ontario. AEFIs following administration of influenza vaccines between September 1, 2012 and August 31, 2015 were extracted from the Integrated Public Health Information System (iPHIS) on September 1, 2015. Events were grouped by provincial surveillance definitions. Reporting rates were calculated using provincial population estimates or net doses distributed as the denominator. The standard World Health Organization definition of serious AEFIs was used. There were 12.1 million doses of influenza vaccine distributed in Ontario and 528 AEFIs reported following influenza vaccines administered over three seasons. The annualized reporting rate was 4.4 per 100,000 doses distributed with a significant decreasing trend over time (p<0.05). The median age was 39.6 years (range six months-96 years); children under four years of age had the highest reporting rate (3.5 per 100,000 population). Disproportionate reporting among females was observed (76.5 percent), most notably in those 18 years and older. The most frequently reported events were injection site reactions (36.2 percent of reports). Others included allergic skin reactions (21.1 percent) and rashes (17.3 percent). Serious AEFIs were rare with a reporting rate of 1.6 per million doses distributed. This assessment found a low rate of reported adverse events following influenza vaccines administered in Ontario. Most reported events were mild and resolved completely. The findings were consistent with the very good safety profile of influenza vaccines.
Highlights
Influenza is a respiratory infection which causes approximately 12,200 hospitalizations and 3,500 deaths in Canada each year [1]
This assessment found a low rate of reported adverse events following influenza vaccines administered in Ontario
Our objective is to summarize influenza AEFIs reported in Ontario during three recent influenza seasons to support a comprehensive evaluation of the Universal Influenza Immunization Program in Ontario
Summary
Influenza is a respiratory infection which causes approximately 12,200 hospitalizations and 3,500 deaths in Canada each year [1]. There are multiple influenza vaccines authorized in Canada for use in individuals six months of age and older. The National Advisory Committee on Immunization (NACI) recommends influenza vaccine to all individuals six months of age and older without contraindications, with particular focus on people at high risk of influenza-related complications or hospitalization and people capable of transmitting influenza to those at high risk [1]. All Ontarians six months of age and older, who live, work or go to school in the Province are eligible for yearly publicly-funded influenza vaccine. Most influenza vaccines in the Province are administered within the Universal Influenza Immunization Program, influenza vaccine products which are authorized for use but not included in the public program may be purchased privately. Post-marketing surveillance of adverse events following influenza vaccine is essential to monitor vaccine safety, inform immunization program planning and evaluation, and build confidence in immunization
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
