Immunization of persons who have newly arrived in Canada is challenging, since immunization records may not exist, records that exist may be difficult to interpret because of language barriers, and immunization schedules and products may differ from those used in Canada. New immigrants, refugees and internationally adopted children may be lacking immunizations and/or immunization records because of their living conditions before arriving in Canada or because the vaccines are not available in their country of origin. Only written documentation of vaccination given at ages and intervals comparable with the Canadian schedule should be considered valid. See the section on Immunization of Children and Adults with Inadequate Immunization Records for additional information.
Although the potency of vaccines administered in other countries can be generally assumed to be adequate, immunization schedules vary. The age at immunization (e.g., 9 months of age for immunization against measles in some countries), the number of doses and the intervals between doses should be carefully reviewed and compared with Canadian and provincial/ territorial recommendations in determining the need for additional doses of vaccines. In many countries outside of Canada, mumps and rubella vaccines are in limited use, and measles vaccine alone is generally given. Haemophilus influenzae type b conjugate, hepatitis B, varicella, pneumococcal conjugate and meningococcal C conjugate vaccines are also in limited use. Information on vaccination schedules in other countries can be found on the following website: http://www.who.int/vaccines/GlobalSummary/Immunization/ScheduleSelect.cfm .
Some studies of internationally adopted children have shown that, despite written documentation of adequate immunizations, serologic evidence of protection against diphtheria and tetanus is lacking in some children. Recommendations regarding an approach to vaccinating these children vary and range from the following:
The epidemiology of some infectious diseases varies in different countries. For example, compared with temperate climates, in the tropics a higher proportion of varicella infections occurs in adults. Therefore, adolescents and adults from these countries are more likely to be susceptible to varicella and require vaccination than those who are Canadian-born. Individuals born in developing countries are more likely to be carriers of hepatitis B, necessitating vaccination of their sexual and household contacts. Hepatitis A immunity is also more likely in some foreign-born individuals, therefore testing for immunity before administering the hepatitis A vaccine to persons from hepatitis A-endemic countries should be considered.
Immigration medical examinations (IMEs) are required for children and adults seeking permanent residence in Canada. These are done within the 12 months preceding arrival in Canada for new immigrants and those seeking refugee status from abroad. In-Canada refugee claimants must undergo an IME within 60 days of claiming refugee status.
It is important to note what the IME does not routinely include:
Therefore health care providers in Canada who see persons newly arrived in the country should make the assessment and updating of immunizations a priority. As well, they should perform a complete health assessment (including comprehensive testing for a variety of chronic and non-vaccine- preventable diseases) as outlined in the references below. As part of this assessment, the following tests are particularly relevant in determining the need for some vaccines or contraindications to vaccination:
Because families new to Canada may return to their country of origin to visit friends and relatives or may receive visitors from their country of origin, vaccination against hepatitis A and/or B should be considered for all members of the family if they are from a country that is endemic for these diseases. A travel medicine consultation is recommended at least 6 to 8 weeks before travel. However, persons new to Canada may not perceive a return to their country of origin as a health risk and so may be less likely to seek pre-travel consultation.
Family members traveling outside of Canada to adopt a baby should also seek pre-travel advice and receive all appropriate travel immunizations. The adoption of a new baby into a family provides an opportunity to review the immunization status of all family members.
Aronson J. Medical evaluation and infectious considerations on arrival. Pediatric Annals 2000;29(4):218-23.
Barnett ED. Infectious disease screening for refugees resettled in the United States. Clinical Infectious Diseases 2004;39(6):833-41.
Canadian Paediatric Society. Children and youth new to Canada: a health care guide. Ottawa: CPS, 1999. URL (for purchase): <http://www.cps.ca/english/publications/Bookstore/ChildrenNewToCanada.htm>.
Centers for Disease Control and Prevention. Travelers' health: yellow book. Health information for international travel, 2005-2006. Atlanta, GA: US Department of Health and Human Services, Public Health Service, 2005; chapter 8. URL: <http://www2.ncid.cdc.gov/travel/yb/utils/ybGet.asp?section=children&obj=adoption.htm&cssNav=browseoyb>.
Chen LH, Barnett ED, Wilson ME. Preventing infectious diseases during and after international adoption. Annals of Internal Medicine 2003;139:371-78.
Stauffer WM, Kamat D, Walker PF. Screening of international immigrants, refugees and adoptees. Primary Care 2002;29(4):879-905.