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Primary Care – Infant and Child Immunization
Whiteboard Animation Transcript
with David Scheifele, MD

https://medskl.com/Module/Index/infant-and-child-immunization

Modern vaccines are safe and impressively effective, potentially eliminating circulation of most target infections. Immunization allows for protection against a broad range of infections.

During pregnancy, transplacental passage of maternal IgG antibodies allows for passive protection in the first 6 months of life. This, however, decays rapidly, with little remaining beyond 6 months of age. Thus, early infancy is the ideal time to begin immunization so that active immunity can replace waning passive protection without a period of vulnerability in between.

To achieve this goal, infants typically require several initial vaccine doses spaced about 8 weeks apart, known as the primary series. It ensures that their immature immune system responds adequately. Adherence to the schedule minimizes infection risks. Depending on the vaccine, a booster dose may be required in the second year of life to reinforce the antibody response and extend protection throughout early childhood; additional booster doses may be needed at 4-6 years and in adolescence to renew and extend protection.

Immunization schedules vary to some extent across regions and you should become familiar with the schedule used in your region of practice.

As clinicians, you will often get asked about the safety profiles of childhood vaccines. In general, almost all of these vaccines are well tolerated and cause very mild side effects, such as injection site pain or transient fever. The tangible risks are febrile seizures and hypotonic (fainting) spells, which both have low risk rates and benign outcomes.

This table lists some of the rare complications associated with vaccines.

MMR meningitis is mainly attributable to the mumps component and differs among products, being very unlikely with the vaccines used in Canada. Measles encephalitis is a great rarity, seen in a few immunocompromised vaccinees.

Lastly, presence of certain health conditions will alter immunization recommendations. Children at high risk for invasive pneumococcal infection should get 3 primary doses of the PCV13 vaccine (instead of 2) and should also receive the 23-valent pneumococcal polysaccharide vaccine after age 2, which is not part of the routine schedule. Immunocompromised children should not receive live attenuated vaccines.