The non-specific effects of vaccines in low income countries.

摘要

In their commentary on my article aboutthe non-specifi c effects of vaccines, PaulFine and David Elliman state that we aredealing with ‘unproven non-specifi c effects’and imply that these effects may not be ofwidespread importance because ‘much ofthe evidence’ comes from Guinea-Bissau.First, proof is never possible in medicine.Second, Fine and Elliman completely ignorethe extensive laboratory evidence of theimportance of non-specifi c (heterologous)immunity. Third, attenuated Mycobacteriumbovis (BCG vaccine) has unequivocal effectson M tuberculosis, M leprae and bladder cancer.Fourth, I presented evidence from 11randomised trials suggesting that BCG andmeasles vaccines reduce mortality fromdiseases other than tuberculosis and measles—and only two of the 11 trials wereperformed in Guinea-Bissau.