[Table of Contents]

Volume: 23S4 - May 1997

Canadian National Report on Immunization, 1996

Preface

Immunization is a cornerstone of improving the health of people worldwide. It is often referred to as the most cost-beneficial of all prevention strategies, resulting in huge savings to society and to health-care systems. Immunization was responsible for the global eradication of smallpox in 1977 and the hemispheric elimination of paralytic poliomyelitis certified by the Pan American Health Organization (PAHO) in 1994.

Many childhood and adult diseases are prevented through proper vaccination. Indeed, vaccine-preventable diseases have experienced a tremendous decrease in Canada, demonstrating the effectiveness of provincial and territorial immunization programs. For childhood vaccine-preventable diseases, the achieved rates of decrease (compared to the pre-vaccine era) have been remarkable: 95% decrease in incidence (e.g. measles, invasive infections due to Haemophilus influenzae type b) or total elimination (e.g. polio). However, vaccine-preventable diseases continue to occur, sometimes in epidemic proportions, as highlighted by recent measles and pertussis epidemics. In addition, cases of congenital rubella syndrome and its devastating effects continue. These have been attributed largely to inadequate immunization in certain populations. The recent increase in pertussis cases in Canada, the importation of wild polio virus during 1992, 1993, and 1996 into Canada, and the diphtheria epidemic in eastern European countries are reminders that, despite current programs, the risk for diseases still exists; it is important to keep the protection level of the population as high as possible.

A 1995 Ontario report emphasizes the importance of recognizing that "... the value of immunization has been established beyond reasonable debate and one takes its benefits for granted"⁽¹⁾.

The success of immunization has three major disadvantages.

• First, it leads to complacency. For example, overall immunization coverage for Canadians was believed to be relatively high for many years; however, no reliable data support this belief. Problems cannot be identified and corrected without close scrutiny of immunization programs. Levels of childhood and adult immunization are still too low; immunization rates, disease prevention, and outbreak protection need to be improved.
• Second, immunization has always had its opponents. Since younger generations have never witnessed or experienced the devastating effects of these diseases, they may tend to abandon or even oppose immunization. A recent national survey revealed that, although the public was usually well informed by health-care providers about the risks of side effects of immunization, they were less informed about the benefits⁽²⁾, which are less risk of contracting diseases and suffering their negative outcomes. Knowing about the risks and benefits of vaccines is important particularly when, unlike many other countries, we do not see the devastating effects of these diseases on children. For example, the World Health Organization (WHO) 1995 Programme Report of the Global Programme for Vaccines and Immunization indicates that one million deaths and nearly 43 million measles cases still occur worldwide annually⁽³⁾.
• Third, every additional advancement in coverage becomes more difficult. It is fairly easy to reach a 50% vaccination coverage. However, as higher coverages are reached, additional gains, although important, are increasingly harder to achieve. While cost-beneficial, benefits become marginal.

Impressive changes have taken place recently on the Canadian scene. National goals have been developed for vaccine-preventable diseases of infants and children. Immunization programs are undergoing greater evaluations, including areas of cold chain and vaccine wastage. Surveillance of vaccine-associated adverse events has been enhanced. Guidelines for assessing vaccine coverage and maintaining cold chain have been developed and published. Draft guidelines for childhood immunization practices are being developed. Mass immunization campaigns have been very successful. New routine programs have been implemented for hepatitis B and second-dose measles immunization. More changes will undoubtedly take place. Some will result from new vaccines becoming available, such as the acellular pertussis vaccines. Funding of immunization programs is anticipated to allow for these changes and will permit enhanced evaluation programs.

At its December 1995 meeting, the steering committee of the Division of Immunization, Laboratory Centre for Disease Control (LCDC), recommended that the Division produce an annual report on immunization achievements in Canada. The current report gives an overview and highlights important issues from a national perspective, although it does not pretend to be an exhaustive review of the immunization situation in Canada. We apologize to provinces and health units for possibly excluding information on some initiatives or omitting specific provincial and territorial data. The report is primarily directed to health-care providers and policy makers. It also provides an opportunity to communicate with the public and increase awareness of immunization programs. It is intended as a tool to help policy makers, health-care workers, and the public measure Canada's progress in reducing the incidence of vaccine-preventable diseases, and to identify actions that can be taken to improve immunization programs. In times of fiscal restraint, it is important to take advantage of new vaccines and to make better use of current ones.

This report attempts to accurately present the current immunization situation and the epidemiology of vaccine-preventable diseases in Canada. It also reviews what happens and what should, but does not, happen.

A complete report is expected to be produced every 3 to 5 years with shorter interim reports annually. Selected sections of the current report will be updated on a more regular basis as well. Each complete report will contain a feature section on a particular disease. Measles was selected for this first report because of the recent effort directed toward its elimination and the mass-vaccination campaigns that took place in 1996.

In 1996, the Division of Immunization, Bureau of Infectious Diseases, LCDC, Health Canada; the Canadian Paediatric Society; the Canadian Public Health Association; and, the Canadian Institute for Child Health, with sponsorship from Connaught Laboratories Limited, organized a national poster competition for grade 6 children. The theme was "Immunizing for Health." The winning poster is presented with pleasure on the cover page; it is a reminder that the goal of immunization is to improve the health of the population. This goal should be encouraged and all the Canadian population should be able to participate.

Comments and updated information to improve future versions of this report would be appreciated. They should be sent to:

Philippe Duclos
Chief
Division of Immunization
Bureau of Infectious Diseases
AL 0603E1, LCDC Building
Ottawa, ON
K1A 0L2

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