New England Journal of Medicine
November 4, 2010  Vol. 363 No. 19
http://content.nejm.org/current.shtml

Correspondence
Poliovirus Vaccine and Vaccine-Derived Polioviruses

To the Editor:
The Perspective article by Modlin1 and the articles on polio immunization by Mohammed et al.2 and Jenkins et al.3 (June 24 issue) reflect the dilemma of eradication: it cannot be accomplished without discontinuing the use of the oral vaccine that has brought us close to eradication. Oral poliovirus vaccine (OPV) strains inexorably revert to virulence. It has been obvious for years that inactivated poliovirus vaccine (IPV) prevents paralysis caused by the passage of poliovirus through the blood to the central nervous system. The article by Mohammed et al. shows that IPV also could be used economically. The article also shows that the serum antibody titer has an inverse effect on the intestinal excretion of poliovirus; this would have been even clearer had the investigators obtained samples later than 1 week after challenge. The authors advocate the development of an IPV based on Sabin strains, although it is likely to be more expensive because of the need for higher antigen content. Also, if the strains used to make IPV escape from the production facility, they would almost certainly revert to virulence. Another solution is to use combination vaccines containing diphtheria, tetanus, pertussis, hepatitis B, Haemophilus influenzae type b, and IPV components in developing countries.

Stanley A. Plotkin, M.D.
University of Pennsylvania, Philadelphia, PA