Global health officials have endorsed a new strategy to eradicate polio, which remains endemic in only three countries — Afghanistan, Nigeria, and Pakistan — by 2018, global news agency AFP reports.

Announced at the offices of the Bill & Melinda Gates Foundation earlier this week, the six-year, $5.5 billion plan calls for eliminating the use of the oral vaccine, which contains live poliovirus and has been blamed for causing outbreaks of the disease on rare occasions, and switching to an injected vaccine made from inactive virus — even though the latter costs at least $2 more per dose than the former.

Supported by the World Health Organization and its partners in the Global Polio Eradication Initiative, the plan also will address recent threats against health workers in Nigeria and Pakistan, where extremists have killed some thirty people associated with the effort, by ramping up security at vaccine stations and reducing the length and profile of immunization campaigns.

Despite these and other challenges, the number of new cases of polio worldwide has dropped from 650 in 2011 to just 223 cases in 2012. "There is a need to sustain the gains," said Gates Foundation vaccine delivery program officer Apoorva Mallya. "We have already interrupted wild virus in many places, India being the latest example, and we need to protect those gains."

Sheridan, Kerry. “'Endgame' Strategy Aims to End Polio Outbreaks in 2014.” AFP 4/03/13.