Immunization against many childhood illnesses is now available. Some are standards according to the World Health Organization recommendations, and others are routinely available only in more affluent or developed healthcare systems. Children in some countries get the full complement of immunizations given in the U.S. The minimum most children get is some or all of the diphtheria, tetanus and pertussis, polio series, and measles vaccination.

Immunization records

Immunization records should be reviewed for reliability and consistency. Children from some countries come with  predictably reliable records. Others are inconsistent and incomplete. An experienced practitioner can assess whether it is legitimate to consider the immunization record valid and reliable. When in doubt, the child should be re-immunization.

The documented vaccinations might not provide  adequate immunity because  of an inconsistent schedule of immunization, a break in the storage safety (i.e., refrigeration), and poor capacity of the child to mount immunity due to impaired health and nutritional status. In addition, vaccinations using multidose vials and multiple dose needles without adequate sterilization carry a risk of actually transmitting diseases, such as HIV and hepatitis B and C.

A child's medical record may also include naturally acquired infection (measles, chickenpox). Clinicians will decide whether to accept these reports.

Antibody tests and re-immunization

Antibody tests can be done to check immunity against most diseases for which immunization is given. Sometimes it's more prudent just to re-immunize without testing, especially when considering the cost of the testing, and that many immunizations can now be given in combination forms, reducing the number of shots. It is generally safe to re-immunize even if the immunity was adequate.

Children who arrive with inadequate documentation should have their antibody titers checked or be re-immunized. Documentation of adequate titers will substitute for a full immunization record for most school systems.
Children without adequate immunity (titers) to the diseases against which they received vaccinations need to be re-immunized.

Children younger than 12-18 months

Checking antibody status in children younger than 12-18 months may demonstrate maternal antibodies, not the child's. Therefore, it is not generally recommended to check the antibodies (titers) on young children.

Recommended immunizations in the U.S.

A complete immunization schedule recommended for children in the U.S. includes:

• Hepatitis B
• Rotavirus (not applicable, as children arrive too late to start)
• Diphtheria, tetanus, pertussis (DTaP)
• Haemophilus influenza type b (hib) (not after >5)
• Pneumococcal (not after > 5)
• Polio
• Influenza
• Measles Mumps Rubella (MMR) (minimum age 12 months)
• Varicella (chickenpox) (minimum age 12 months)
• Hepatitis A. (minimum age 12 months)
• Human Papillomavirus ( HPV) (minimum age 9)