Israel Medical Association Journal

Immunization coverage is a major health indicator. In Israel, routine childhood immunizations are provided at community public well-baby clinics. Immunization monitoring is an important cornerstone of a national health policy however, data obtained through sampling carries the risk of under-representation of certain population strata, particularly high risk groups. Despite high national average immunization coverage, specific sub-populations are under-immunized, as highlighted by outbreaks of vaccine-preventable diseases. The mean national immunization coverage at age 2 years (2006 data) was: DTaP[1]-IPV[2]-Hib4[3] (all 93%), HBV[4]3 (96%), MMR1[5] (94%), HAV1[6] (90%). These reports are based on a 17% population-based sample in some districts and on cumulative reports in others. A national immunization registry requires data completeness, protection of confidentiality, compulsory reporting by providers, and links to other computerized health records. It should provide individual immunization data from infancy to adulthood and be accessible to both providers and consumers. In 2008 the Israel Ministry of Health launched a national immunization registry based on immunization reporting from well-baby clinics using a web-based computerized system. As of January 2010, 120 well-baby clinics are connected to the nascent registry, which includes the records of some 50,000 children. The implementation of a comprehensive national immunization registry augurs well for the prospect of evidence-based assessment of the health status of children in Israel. 

 
[1] DTaP = diphtheria-tetanus-acellular pertussis

[2] IPV = inactivated polio vaccine

[3] Hib = Haemophilus influenzae b

[4] HBV = hepatitis B virus

[5] MMR = measles-mymps-rubella

[6] HAV = hepatitis B virus

The human papillomavirus family of viruses causes a variety of benign, premalignant and malignant lesions in men and women. All cervical cancers are caused by HPV[1]. It is the leading cause of death from cancer in women in developing countries; every year some 493,000 women develop cervical cancer and 230,000 women die every year of this disease. The vaccine against HPV includes virus-like particles, composed of the major viral capsid protein of HPV without the carcinogenic genetic core. Large-scale studies have shown that the vaccine is tolerated well, leads to high antibody levels in both men and women, and prevents chronic HPV infection and its associated diseases. To achieve effective coverage the vaccine should be given prior to sexual debut. Introduction of the vaccine into specific countries, particularly Israel, should take into account the local incidence of cervical cancer as well as the increasing incidence of precancerous cervical lesions and genital warts, which reduce quality of life and are associated with considerable costs.

Background: Poliovirus rapidly evolves by nucleic acid substitutions and genetic recombination with other polioviruses and non-polio enteroviruses. Evolving oral poliovirus (Sabin strains) can rapidly revert to neurovirulence and undergo antigenic alterations.

Objectives: To evaluate the threat of vaccine-derived poliovirus (1–15% divergence from the respective Sabin strain) for a poliomyelitis-free population in a country with a long-standing routine vaccination program.

Methods: We characterized genetic and antigenic changes in OPV[1] strains isolated from sewage in Israel and evaluated intestinal immunity by measuring fecal excretion after OPV challenge of vaccinated children.

Results: Characterization of poliovirus from sewage revealed eight type 2 and three type 3 vaccine polioviruses that had replicated and started to evolve (vaccine that replicated and diverged by 0.5 to ≤ 1.0%) and nine highly diverged type 2 vaccine-derived polioviruses (1–15% divergence from the respective Sabin strain) with 8–14% divergence between the years 1998 and 2005. Six of the eleven VRPV[2] uniquely recombined with OPV and/or NPEV[3]. The nine VDPV[4] were epidemically related, genotypically neurovirulent, and had 10–15 amino acid substitutions in antigenic sites altering their antigenicity, but shared a single recombination. Type 2 OPV was excreted by 23% and 17% of infants challenged with OPV 3 months after partial immunization (two doses each of OPV and enhanced inactivated poliovirus) or full immunization (three doses of each) respectively, despite high humoral antibody titers.

Conclusions: Our findings, which show that OPV is excreted for a significant period by children with high humoral immunity, emphasize the long-term potential threat from VDPV in highly vaccinated populations. An adequate immunization program, combined with environmental surveillance, is necessary to prevent poliomyelitis and community transmission of poliovirus.