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The dose that works for adults might not be appropriate for youngsters of different ages.
Some vaccines need to be given multiple times.
CDC National Center for Immunization and Respiratory Diseases, CC BY
After 4 years of age and through younger adult life, your immune system tends to be more responsive and less prone to forgetting. It’s not a coincidence that this is when people tend to gain most of their allergies. For the COVID-19 Pfizer vaccine, researchers found that kids ages 5 to 11 had a similar immune and safety response at one-third the dose used for those ages 12 and up.
Scientists tend to start with patients between ages 18 and 55 years old when studying vaccines. Their adult immune systems have matured and they can be counted on to reliably report any adverse reactions. Seeing what happens in the adult age group also helps physicians predict what might occur when a vaccine is administered to others and be on the lookout for these side effects in the younger age groups.
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Around age 55 or so, the adaptive immune system starts to become weaker again and forgetful, in some ways more like the infant’s developing system. Luckily vaccine boosters can provide a quick refresher for these older patients – like helping protect them from accidental falls after a lifetime having mastered walking and running.
In the end, vaccines provide the safest environment for the immune system to learn, and tweaking the dosages for different age groups helps ensure that each patient gets just what’s necessary to get the job done.
Brian Peppers, Assistant Professor of Pediatric and Adult Allergy/Immunology, West Virginia University
This article is republished from The Conversation under a Creative Commons license. Read the original article.