Concept: Childhood Immunizations

Introduction

This concept provides information on childhood immunizations, including the immunization schedule, access to immunization tariff codes that identify DPT (diphtheria, pertussis and tetanus), Polio, HiB (haemophilus influenza B), MMR (measles, mumps and rubella), and pneumococcal conjugate vaccine (PCV). It also includes information on how the immunization schedule has changed over time. Immunization rates available from MCHP publications are also available through links to this information. This concept also provides a link to an example of SAS code for determining "complete" immunizations (up to 2007). Please see the SAS code and formats section containing the following link to: Compute 1 and 2 year Rates of Immunizations - SAS Code - (internal access only).

In Manitoba, the three levels of government - municipal (City of Winnipeg), provincial, and federal - and two types of providers - physicians (approximately 80%) and public health nurses (20%)- are involved in the delivery of immunizations. Immunizations are provided through a longstanding provincial program. The Manitoba Immunization Monitoring System (MIMS) records all immunizations of provincial registrants (as of Jan 1, 1980) and provides monitoring and reminders to families.

MIMS files contain:


• registry information
• a code that identifies the vaccine administered and its sequence in the immunization schedule
• service date
• provider identifiers-to distinguish physician administered immunizations from those given by public health nurses

Comparisons between physician and MIMS records have shown data quality for the non-aboriginal population to be high. Two percent or fewer immunizations or service dates are coded incorrectly, while physician failure to bill has been estimated at between 0.2% (urban) and 6.6% (rural).

Immunization Schedule

In order for a child to be considered completely immunized, a minimum number of doses of each type of vaccine must be received within the first few months, up to 2 years of age.

NOTE: Over time, there have been changes in the recommended immunization schedule. The information below identifies some of these changes:


• In 1984 the recommended childhood immunization schedule was:
  • DPT (diphtheria, pertussis and tetanus) at 2, 4, 6 and 18 months
    
  • OPV (oral polio vaccine) at 2, 4, 6 and 18 months
    
  • MMR (measles, mumps and rubella) at 12 months
  
  
• In 1992, Hib (haemophilus influenza B) vaccine was added at 2, 4, 6 and 18 months
  
  
• In 1997, OPV was replaced with IPV (inactivated polio vaccine). This was combined with the DPT vaccine as a quadravalent vaccine. Hib was also added to form a pentavalent vaccine.
  
  
• In Martens et al. (2003), they followed the recommended immunization schedule for infants and children in Manitoba, in the first 2 years of life for 2001.

  Age at vaccination	DPT	Polio	HiB 1	MMR
  2 months 4 months 6 months 12 months 18 months	X X X X	X X (X) X	X X X X	X

  NOTES:
  

  • (X) - this dose is not needed routinely, but can be included.
    
  • ¹ HiB (Hemophilus influenza B) vaccine added mid-1992.
    
  • Hepatitis B has been offered to all Grade IV students since Fall of 1998, but there is not currently any schedule for children.

• In 2004, three vaccines applicable to this age group were introduced
  • influenza for infants age 6 - 23 months
  • pneumococcal conjugate at 2, 4, 6 and 18 months of age
  • varicella at age 12 months.
  
  
• In Chartier et al. (2012), , they compared complete immunization rates of Francophone and all other Manitoban children using the following recommended schedule for 2006/2007:
  
  • four Diphtheria, Acellular Pertussis, Tetanus (DTP) immunizations;
    
  • three Polio immunizations;
    
  • four Haemophilus Influenzae type B (HiB) immunizations
    
  • one Measles, Mumps, and Rubella (MMR) immunization;
    
  • one Varicella immunization; and
    
  • four Pneumococcal Conjugate 7 (PCV-7) immunizations.
  
  
• In Smith et al. (2013), they measured childhood immunization completion rates over two years (2007/08 to 2008/09) using the same immunization schedule presented above for 2006/2007.
  
  
• In 2009, meningococcal conjugate C (Men-C) was added to the schedule; one dose at 12 months and another dose in grade 4.
  
  
• In July, 2010 the pneumococcal conjugate vaccine (PCV) was transitioned from PCV-7 to PCV-13. Children who started with PCV-7 continued and finished their immunization series with PCV-7. Children starting after July 2010 would have been given PCV-13.
  
  
• In July 2012, Manitoba Health offered a single booster of PCV-13 to children under the age of 5 who had never received PCV-13. Also in July 2012, a schedule change in PCV-13 reduced the amount of doses to three for children who are not at high risk of pneumococcal infection. Children at high risk continued to receive a total of four doses.
  
  
• In Katz et al. (2014), they investigated complete childhood immunizations by age 2 using the schedule presented in Table 3.2 - Doses Required to be "Complete for Age" for Two Year-Olds of the report.
  
  
• In Chartier et al. (2020), they investigated complete childhood immunizations by age 2, from children born in 2009 to 2013 until the end of 2015, using the schedule presented in Appendix Table 2.1: Technical Definitions - Complete Vaccination (Two Year Olds) of the report.

Current Information from Manitoba Health

For current information on recommended immunization schedules, click on the following links that are available on the Manitoba Health - Communicable Disease Control website:



• Recommended Immunization Schedule for Infants and Pre-School Children ; and
  
• Recommended School Immunization Schedule

Working with Immunization Tariff Codes

Tariff codes for immunizations have responded to changes in vaccine technology over the last several years. Not only are vaccines being improved in terms of efficacy and reduction of adverse effects, but the trend has been toward combining several antigens into one vaccine. The greater convenience of these combined doses makes them easier for the health care provider to administer, making it more likely that the required number of doses of each will be given on time.

Counting immunizations is equivalent to a search for tariff codes. The date of the immunization must also be checked to see if it falls within the specified time period. Any doses outside of this time period (i.e. too late) are not counted. For example, according to the 2001 immunization schedule, in order to be considered at one year, a child requires three DPT, two Polio, and three Hib vaccines in the first 12 months of life. The MMR at 12 months is not usually counted in this first 12 month period. The Canadian Immunization Guide 1998 states this dose should be given "shortly after the first birthday." Tables for subsequent periods, such as 13 months or 18 months, should count the MMR.

Tariff Codes

The following sources provide a list of tariff codes used to identify immunizations in MCHP research:


• For a list of Childhood Immunization tariff codes from 1987 to 1999, used in Martens et al. (2003), please see the Manitoba Childhood Immunization Tariff Codes - 1987 to 1999 document.
  
  
• For vaccine tariff codes used in Hilderman et al. (2011), please see Appendix 1: Tariff Codes for Vaccinations .
  
  
• For a list of tariff codes used in Smith et al. (2013), please see the Physician Tariffs listed in Appendix Table A2.1 for the Childhood Immunization Completion Indicator.
  
  
• For a list of tariff codes used in Katz et al. (2014), please see the physician tariff codes for vaccinations listed in Appendix Table 1.1 - Childhood Immunizations Indicator
  
  
• For a list of the tariff codes used in Chartier et al. (2020), to identify complete vaccinations in two-year olds over time (2009 to December 31, 2014), please see the tariff codes listed in Appendix Table 2.1: Technical Definitions - Complete Vaccination Two-Year Olds .

Tariff Codes - Manitoba Health

For a current list of active and cancelled MIMS tariffs from Manitoba Health, please see Manitoba Health Web Site - MIMS Tariffs - Quick Reference for Health Professionals .

Immunization Rates Available Through MCHP Publications

Several MCHP publications have reported immunization rates. These include:


• Martens et al. (2003) calculated immunization rates for each Regional Health Authority (RHA) and for each RHA District in Manitoba. The following three Excel spreadsheets are available to download:
  
  
  • 1 Year Immunization Rates By RHA and RHA Districts
    
  • 2 Year Immunization Rates By RHA and RHA Districts
    
  • 7 Year Immunization Rates By RHA and RHA Districts
  
  
• Hilderman et al. (2011) produced a number of figures and tables related to specific vaccines and immunization rates. Please see the List of Figures and List of Tables for specific information available from this report.
  
  
• Chartier et al. (2012), measured childhood immunization completion rates for two-year-old children, comparing Francophone children to all other Manitoban children. Please see the section titled Figure 7.1.1: Complete Immunization Schedule for Two–Year–Olds in this report for more detailed information.
  
  
• Smith et al. (2013), measured childhood immunization completion rates for two-year-old children over two years (2007/08 to 2008/09) for Regional Health Authorities (RHAs) and Winnipeg Community Areas (CAs). Please see the section titled Two-Year-Old Immunization Completion in this report for more detailed information.
  
  
• Katz et al. (2014) investigated complete immunizations at age two related to the implementation of Physician Integrated Network (PIN) clinics. Please see the section titled Complete Immunizations at Age Two in this report for more detailed information.
  
  
• Chartier et al. (2020) investigated complete vaccinations for two-year olds in First Nations children, both on-reserve and off-reserve, compared to all other Manitoban children. This includes analysis by Health Region, Tribal Council Area and Income Quintiles. Please see the section titled Complete Vaccination (Two-Year Olds) for more detailed information.