WHO recommends switching to injectable polio vaccine

"[T]his month the World Health Organization (WHO) in Geneva, Switzerland, proposed a shift in [polio] vaccination strategy from oral vaccines to injected ones that may have to be administered in clinics," Nature reports, adding, "The change is needed to mop up the last remaining pockets of polio, but experts say that it poses challenges in [rural areas], which have poor access to health care." The oral polio vaccine, developed by Albert Sabin and in widespread use through the Global Polio Eradication Initiative (GPEI), contains three inactivated strains of polio, and while the vaccine is cheap and easy to administer, the inactivated virus can revert to disease-causing forms, the journal notes.

"In a 4 January announcement, the WHO called for oral polio vaccine containing the polio strain type 2, one of the Sabin vaccine strains, to be phased out" because wild type 2 polio has been eliminated worldwide, and the policy also called for "the introduction, as quickly as possible, of the oral vaccine's old competitor: the inactivated Salk vaccine," a more expensive, injectable vaccine, according to the journal. "But it carries no risk of causing polio," Nature writes, adding, "By giving children an inactivated vaccine that protects against all three subtypes of polio, health workers hope to gradually stamp out vaccine-derived outbreaks." The journal notes, "The high cost of the inactivated polio vaccine remains a significant hurdle for the plan," as does the lack of health care infrastructure in affected areas. However, health experts hope the injectable vaccine can be included in routine immunizations, the journal adds (Callaway, 1/14).