Intended for healthcare professionals


Vaccine programmes must consider their effect on general resistance

BMJ 2012; 344 doi: (Published 14 June 2012) Cite this as: BMJ 2012;344:e3769
  1. Peter Aaby, professor 1,
  2. Hilton Whittle, professor2,
  3. Christine Stabell Benn, centre leader13
  1. 1Bandim Health Project, Indepth Network, Bissau, Guinea-Bissau
  2. 2London School of Hygiene and Tropical Medicine, London, UK
  3. 3Research Centre for Vitamins and Vaccines (CVIVA), Bandim Health Project, Statens Serum Institut, Copenhagen, Denmark
  1. Correspondence to: P Aaby, Bandim Health Project, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark P.aaby{at}
  • Accepted 27 March 2012

Recent randomised trials have shown that live vaccines such as measles and BCG enhance general resistance, preventing other infections as well as the target infection. However, current vaccination strategies assume a proportionate response. Peter Aaby, Hilton Whittle, and Christine Stabell Benn argue that we need to rethink our approach

Global health leaders have committed to making 2010-19 the decade of vaccines, with the aim of ensuring that lifesaving vaccines are available globally. The Bill and Melinda Gates Foundation pledged $10bn (£6.5bn; €8bn) to the new decade,1 which was established in recognition of the astonishing technological progress in developing new vaccines and our ethical obligation to make these vaccines available to all children in the poorest countries of the world.1 2 w1-8 The ultimate goal is to save lives, and vaccination programmes measure potential impact in terms of the lives saved.1 2 w1

Surprisingly, therefore, there are few observational studies and virtually no randomised clinical trials documenting the effect on child mortality of any of the existing vaccines. A notable exception is the high titre measles vaccine, which was withdrawn because an interaction with diphtheria-tetanus-pertussis (DTP) vaccine resulted in a 33% (95% confidence interval 2% to 73%) increase in mortality among children aged 4-60 months in several west African randomised trials.3 w9 Among the newer vaccines, conjugate pneumococcal vaccine has been found to be associated with an 11% (−1% to 21%) reduction in mortality in a meta-analysis.4

The lack of data on mortality is not considered a problem. If a vaccine is shown to produce immunity against a specific disease, the effect on survival is estimated using the burden of disease, and the efficacy and the coverage of the specific vaccine. For example, if rotavirus causes 527 000 annual deaths, 90% occurring in low income …

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