How are vaccines tested for very young children or infants? [closed]

Question

I've heard people claim that vaccines aren't tested before being given to infants. I looked into it and found lots of references to extensive human trials, but the best reference I've found about testing in children is this from a site run by the College of Physicians of Philadelphia:

If the vaccine is intended for children, researchers will first test adults, and then gradually step down the age of the test subjects until they reach their target.

But how do they do tests in very young children or infants? It seems a bit weird for any parent to want to sign their newborn up for drug trials. Can anyone provide an authoritative reference on this?

Answer 1

It seems a bit weird for any parent to want to sign their newborn up for drug trials.

Weird or not, that's how it's done. If your kids are at risk of a dangerous disease, free vaccination and healthcare accompanying the trial may be an attractive proposition, even if it's on an experimental basis.

For example, "Tameris et al.: Lessons learnt from the first efficacy trial of a new infant tuberculosis vaccine since BCG":

Mothers of infants of 6 weeks or older were approached for possible participation in the trial. Once informed consent had been signed by the legal guardian, the infants were randomised sequentially into one of five cohorts starting with an initial safety cohort of at least 330 participants, followed by three immunogenicity cohorts of up to 60 participants each and the final, largest correlates of protection cohort of 2400.