Will multiple injections overwhelm the immune system?
No. Every day our
bodies come into contact with millions of germs, causing our immune system to
work continuously to protect us. So exposure to a few antigens (parts of weak
or dead viruses or bacteria) in vaccines is easily handled by our immune
systems. In fact, our immune system needs to be challenged continually to stay
vigorous. Modern biotechnology has actually reduced the number of antigens in
today’s vaccines. For example, in 1980 the DTaP vaccine alone had 3017 antigens.
Today, at the two-month visit there are a total of 34 antigens in all the
recommended vaccines for that age – just 34 antigens, among the millions
handled every day by our immune systems.
Canadian Immunization Guide. Evergreen edition. http://www.phac-aspc.gc.ca/publicat/cig-gci/index-eng.php (external link)
Your Child's Best Shot (3rd edition, p. 322) (external link)
Public Health Agency of Canada – Frequently Asked Questions (external link)
Immunization Communication Tool for Immunizers (ImmunizeBC, 2008) (external link)