Vaccinate against a bacterial infection and you can prevent it ever occurring, thus eliminating the need for antibiotic treatment. Meningitis and pneumonia caused by the bacterium Streptococcus pneumoniae illustrate the point. These diseases are estimated to kill more than 800,000 children under the age of 5 every year, yet a vaccine against S. pneumoniae already exists.
If every child was vaccinated, the number of days when children under 5 are taking antibiotics against this bacterium would be cut by 47 per cent. Such a drastic reduction would, in theory, make drug-resistant strains much less likely to evolve.
We have some successful examples of this strategy, says George Griffin of the Academy of Medical Sciences in London. In the UK, children are given a vaccine against meningitis C and Haemophilus influenzae type b. “Undoubtedly, that has completely altered the pattern of meningococcal disease and H. influenzae b occurrence, and that should therefore have reduced the amount of antibiotics given,” says Griffin.
But while organisations like UNICEF and Gavi are working to improve worldwide coverage of existing vaccines, there are several resistant pathogens for which vaccines are still a long way off. Most worrying are strains that have developed resistance to carbapenems, the drugs that were until recently one of our last lines of defence against resistant bacteria.
The new report warns that there are no vaccines currently in use for carbapenem-resistant E. coli, gonorrhoea and C. difficile, and too few candidates in clinical trials.
One problem is that new, experimental vaccines have a low success rate, and it often takes more than 10 years to bring one vaccine to market. This reduces the incentive for pharmaceutical firms to develop novel vaccines.
The report is the latest in a series by the Review on Antimicrobial Resistance, before the panel makes its final recommendations to the UK government in May. These are expected to include a package of actions to tackle drug-resistant infections globally.
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