Perhaps one of the greatest disappointments in global health in recent years has been the failure of the global health community to make progress towards eradication of polio. Largely due to lack of acceptance of vaccination in parts of Nigeria and the increased movement of people around the world, polio suffered some serious set backs in recent years.
It is therefore extremely exciting to read about some good news on the polio front. In last week’s NEJM, there was an editorial and two research articles of two clinical studies that suggests that a newly developed monovalent (targets one type of virus) vaccine has much higher efficacy against the type 1 strain and since only a single dose of the vaccine is needed, could lead to much higher gains in coverage, at least in the short-term against that particular strain.
The use of monovalent versions was largely abandoned in favor of triple valent versions (there are many kinds of strains of the virus in circulation) but I this approach was adopted largely through logical reasoning (why not give three instead of one?) rather than being based on some real world study of the comparative efficacy of the vaccines or the implications of efficacy for effectiveness. What the studies above show is that if you can use a vaccine that does a much better job at protecting against type 1 virus, and that this vaccine allows you to only give it once, you might be much better off giving the monovalent vaccines individually than together. Clearly a monovalent vaccine against the other major strain (namely 3) would also be needed, but that it may be better to give it separately.Share on Facebook