Highlighting the Safety and Effectiveness of Vaccines


21 Nov 2016

Ontario distributed some nine million doses of vaccines through its public vaccination programs last year, and saw very few adverse reactions, notes Public Health Ontario’s 2015 Annual Report on Vaccine Safety in Ontario.

“Vaccines are one of the safest and most effective advances that we’ve made in public health to promote health and prevent both infectious diseases and some cancers,” notes Dr. Shelley Deeks, medical director of immunization and vaccine-preventable diseases at PHO. “Vaccines save lives and protect us from serious diseases, and the 2015 vaccine safety report reiterates that they are safe.”

The report is a comprehensive annual provincial assessment of vaccine safety. Approximately nine million doses were distributed across the province in 2015, and reports of serious reactions remained very rare. Of the 678 reactions reported, 34 (or four out of every million doses distributed) were considered serious, such as cellulitis, Guillian-Barré syndrome or other reactions requiring hospitalization. The vast majority of reported reactions were mild – soreness around the injection site, rashes and allergic skin reactions and most had recovered by the time of the assessment.

“We continue to encourage public health units and health care providers to report adverse reactions so that we’re able to monitor vaccine safety in Ontario. Monitoring vaccine safety helps us document that the risks of vaccination are very low, especially when compared to the risks of illness from the dangerous diseases that vaccines help prevent,” says Dr. Deeks. “It also allows us to identify safety signals, if they were to occur.”

There is considerable evidence showing that vaccines are not only safe but effective. As one example, recently published research led by Dr. Deeks found that Ontario’s human papillomavirus (HPV) vaccination program led to a drop in young women contracting genital warts, a sexually transmitted infection caused by certain strains of HPV. Certain types of HPV are especially dangerous for women because they can also cause cancer of the cervix, other anogenital cancers, and head and neck cancers. In the study, researchers examined the impact of Ontario’s HPV vaccination program on the incidence of genital warts in the province by comparing data before and after the introduction of the program. Dr. Deeks says the findings were very clear – they saw a marked decrease in genital warts among young women when comparing the pre- and post-immunization program periods.

Quick Facts:

  • Most people who receive vaccines experience no side effects; in a small number of cases, vaccines can cause minor reactions such as soreness at the injection site.

  • An adverse reaction or event is an unwanted or unexpected health effect that happens after someone is vaccinated. It may or may not be caused by the vaccine.

  • All vaccines are extensively tested before use and monitored continuously for safety and effectiveness. In Canada, vaccines are closely monitored by governments and manufacturers.

  • In Ontario, local public health units investigate reported adverse reactions and provide support to health professionals who administer vaccines, individuals and their families.

The Annual Report on Vaccine Safety in Ontario, 2015, is available here.

Chat icon




Updated 21 Nov 2016