Polio vaccination programs not reaching enough children in Afghanistan and Pakistan

New, more effective vaccines are struggling to have an impact in the drive to eradicate polio in Afghanistan and Pakistan because not enough children are being vaccinated, according to a study published in the Lancet medical journal today. Sharp declines in vaccine uptake led to a rise in the number of new infections between 2006 and 2011, even though new vaccines introduced during this time have proven to be more effective against the main circulating strain of the virus. Poliovirus exists in three strains, with type 1 the most prevalent and type 2 unseen anywhere in the world since 1999. It mainly affects children under five and causes paralysis in about one in 200 cases. In most parts of the world it has been eliminated by sustained vaccination programmes in the late 20th century. Afghanistan and Pakistan are among only three countries – along with Nigeria – that have never managed...