World Immunisation Week special blog: What Europe can learn from North America

Addressing Adult Immunization with the Same Passion as the Paediatric Program


On an almost daily basis there is a media story discussing an outbreak of a vaccine-preventable disease in a paediatric patient population. Healthcare professionals, public health officials and parent groups are commonly quoted regarding the negative impact of low immunization rates and vaccine exemptions on public health. Governments and public health in most countries have media campaigns on the importance of immunization in children and most healthcare professionals actively promote immunization through the first 18 years of life. But something happens when our patients reach their 18th birthday.

The Success of the Paediatric Immunization program


Don’t get me wrong, I am firm supporter of the paediatric immunization program and strongly support the efforts to ensure all of our children are protected. High paediatric immunization rates have had such a tremendous impact and are responsible for saving more lives than any other public health intervention.1

But looking at the most recent immunization data from the United States, we are achieving 90% coverage for Measles-Mumps-Rubella (MMR), polio, hepatitis B and varicella in children 19 to 35 months.2 Less than 1% of this patient group has not received any immunization and vaccine exceptions remain low at 1.7%.3

Without question, the public health campaigns and healthcare professional focus has and will continue to impact the high immunization rate in our children.

What about our Adult Patients?


Prevention of disease by immunization is not just for children; adults require immunization to restore waning immunity against some vaccine preventable diseases and to establish immunity against other diseases that are more common in adults.4 Overall, the prevalence of illness attributable to vaccine-preventable diseases is greater among adults aged ≥19 years than among children aged ≤12 years.5 Adults are at an elevated risk of morbidity and mortality from a number of vaccine preventable diseases, such as:

  • Influenza
  • Pneumococcal disease
  • Tetanus
  • Diphtheria
  • Herpes zoster
  • Measles, mumps and rubella

Vaccine Coverage in Adults


In February 2016, the Morbidity and Mortality Weekly Report shared the most recent information on adult immunization rates in adults. Although the United States is achieving excellent pediatric immunization coverage, the adult vaccine coverage is far from optimal (Table 1).5

Only 1 in 5 patients at high risk of invasive pneumococcal disease are adequately protected

Table 1 –  United States Adult Immunization Rates August 2013-June 20145
Influenza vaccine
  •          Influenza vaccination coverage among adults aged ≥19 years was 43.2%.
Pneumococcal vaccine
  •          Pneumococcal vaccination coverage among high-risk persons aged 19–64 years was 20.3%
  •          Coverage among adults aged ≥65 years was 61.3%
Tetanus-diphtheria (Td) vaccine
  •          Td vaccination coverage among adults aged ≥19 years was 62.2%
Hepatitis A vaccine
  •          Hepatitis A vaccination coverage among adults aged ≥19 years was 9.0%
Hepatitis B vaccine
  •          Hepatitis B vaccination coverage among adults aged ≥19 years was 24.5%
HPV vaccine
  •          HPV vaccination coverage among adults aged 19–26 years was 40.2% for females and 8.2% for males


Reasons for Low Immunization Rates in Adults


Health care providers have a responsibility to ensure that adults under their care have continuing and updated protection against vaccine preventable diseases through appropriate immunization.4 The Canadian Immunization Guide provides some of the reasons for poor vaccine uptake in adults (Table 2).4

Table 2 – Common Reasons for Incomplete Immunization in Adulthood4
  •          Lack of recognition of the importance of adult immunization
  •          Lack of recommendations from health care providers
  •          Lack of health care provider’s knowledge about adult immunization and recommended vaccines
  •          Misrepresentation and misunderstanding of the risks of vaccine and benefits of disease prevention in adults
  •          Lack of understanding of vaccine safety and efficacy
  •          Missed opportunities for vaccination in health care providers’ offices, hospitals and nursing homes
  •          Lack of publicly funded vaccine and reimbursement to vaccine providers
  •          Lack of coordinated immunization programs for adults
  •          Lack of regulatory or legal requirements
  •          Fear of injections
  •          Lack of availability of up-to-date records and recording systems

Adapted from Reference 4

How do we Improve Adult Immunization Rates


Without question, all healthcare and public health professionals have to do more to ensure that our patients are adequately protected from common vaccine-preventable diseases. We need a different method of identifying vaccine candidates and improving the discussion on vaccines for ongoing protection.

The Canadian Immunization Guide provides a comprehensive list of opportunities to discuss adult vaccines (Table 3).  Some strategies which I feel will improve adult immunization rates are reviewed in Table 4.

Table 4 – Opportunities for General Immunization Counselling of Adults4
  •          New patient encounters
  •          Periodic health examinations
  •          Pregnancy and the immediate post-partum period
  •          Visits for chronic disease management
  •          Assessment of new immigrants
  •          Parents attending their child’s vaccination visits
  •          Hospitalization, especially when diagnosed with a                      chronic disease
  •          Management protocols on admission to nursing homes,            long-term care institutions, and acute care institutions
  •          Management protocols on admission to health                            professional training programs
  •          New employee assessments in day care, health care and            health care-related facilities
  •          Persons requesting specific vaccination(s)
  •          Persons with evidence of risk taking behaviour, such as            illicit drug use or a sexually transmitted infection
  •          Individuals requesting advice concerning travel


Table 5 – Strategies to Increase Adult Immunization Rates
Vaccine Registries
  • Canada, like other nations in the world does not have a national vaccine registry
  • The use of a registry can help to identify potential candidates and engage patients and their health care professionals to ensure they are protected
  • Through the use of this technology and the ability to audit the data, public health officials can direct resources to areas with low vaccine coverage or those patient populations with elevated disease risk
Vaccines should be given at any interaction with the healthcare system
  • In many parts of the world, there are limits on where a patient can receive a vaccine and by which healthcare professional that can deliver it
  • The more access patients have to healthcare professionals who can inject vaccines, the more frequent the potential discussions regarding their role in reducing morbidity and mortality
  • Ideally all healthcare professionals should be able to inject public health vaccines for adults. This allows them to identify a vaccine candidate and inject immediately versus missing an immunization opportunity
Universal coverage for recommended vaccines
  • Most countries have some form of publically funded routine immunization program
  • Many patients will refuse to pay for an intervention that reduces their risk of disease. They may not have the resources or do not see the value
  • Providing vaccines to high-risk patients without insurance coverage can protect this highly vulnerable patient population
Integrate vaccines into clinical practice guidelines and age-related documentation
  • Many chronic diseases increase the risk of vaccine-preventable diseases
  • Having clinical practice guidelines reviewing the need for immunization can be beneficial to stimulate healthcare professional vaccine discussions in patients with these chronic conditions
  • The Canadian Diabetes Association Guidelines does this well with a chapter on influenza and pneumococcal immunization in their guideline document
  • There is continuous information sent to high-risk adult patients (e.g. ≥ 65 years old, patients with diabetes or chronic respiratory conditions) from governments or organizations. Consider adding information on vaccines in this information to increase the awareness of adult immunization
Public health campaigns
  • Consider adding adult immunization into the current paediatric immunization media campaigns. Pictures of families where multiple members are being protected (e.g. child, father/mother, grandparent) can stress that immunization is a family issue and not just a childhood issue

Working Together to Improve Public Health


All healthcare professionals, public health officials and governments have a role to play in protecting adults from common disease states. Through the active promotion and uptake of adult vaccines, we can reduce the burden of these diseases on our population.



  1. Public Health Agency of Canada Government of Canada. Benefits of Immunization – Part 1 – General Guidelines – Canadian Immunization Guide. Published July 18, 2007. Accessed April 23, 2016.
  2. Center for Disease Control. Vaccination Coverage | NIS Child | 1994-2014 Figures by Vaccine | CDC. Accessed April 23, 2016.
  3. Annunziata K, Rak A, Del Buono H, DiBonaventura M, Krishnarajah G. Vaccination Rates among the General Adult Population and High-Risk Groups in the United States. PLoS ONE. 2012;7(11). doi:10.1371/journal.pone.0050553.
  4. Public Health Agency of Canada Government of Canada. Immunization of Adults – Part 3 – Vaccination of Specific Populations – Canadian Immunization Guide – Public Health Agency of Canada. Published July 18, 2007. Accessed February 10, 2016.
  5. Williams WW, Lu P-J, O’Halloran A, et al. Surveillance of Vaccination Coverage Among Adult Populations — United States, 2014. MMWR Surveill Summ. 2016;65(1):1-36. doi:10.15585/mmwr.ss6501a1.