Poliomyelitis control in Israel, the West Bank and Gaza Strip: changing strategies with the goal of eradication in an endemic area.

Israel has faced the challenge presented by epidemic poliomyelitis by using different immunization strategies. In the 1950s, inactivated poliovirus vaccine (IPV) helped to reduce the total burden of the disease, but cases continued to occur. Introduction of oral poliovirus vaccine (OPV) in mid-1961 had a dramatic effect in controlling an extensive epidemic of poliomyelitis; however, poliovirus activity and cases continued during the 1970s, and at a low level in the 1980s.

Susceptibility to HIV-1 infection of a human B-lymphoblastoid cell line, DG75, transfected with subgenomic DNA fragments of Epstein-Barr virus.

We have previously shown that the presence of the EBV genome and active EBV infection in some Burkitt's lymphoma cell lines confer the susceptibility of HIV-1 infection in spite of the absence of surface CD4 receptors in these cells. In the present study we used an EBV genome negative Burkitt's lymphoma B-cell line, DG75, transfected with three different subgenomic fragments of EBV expressing the nuclear antigens (EBNA1 and EBNA2) and the latent membrane protein (LMP), respectively. Immunofluorescence analysis demonstrated CD4 expression in more than 90% of the EBNA1, EBNA2 and LMP transfected cell lines, whereas the antigen could only be detected in less than 4% of the parental DG75 cell line.

Use of a combined DTP-polio vaccine in a reduced schedule.

A five-year serologic follow-up and a four-year monitoring of the polio and pertussis morbidity in an area immunized with a 2 + 1 dose schedule of a combined DTP-Po vaccine have shown that: the individual protection against polio measured by the presence of neutralizing antibody persists at a very adequate level five years after the first booster; after three years of a steady high proportion of children with pertussis antibody, a considerable drop is observed and in about 28% of individuals agglutinin levels of less than 1:20 were found five years after booster; the community protection against paralytic poliomyelitis and pertussis is satisfactory up to four years after the introduction of the program. Continuation of immunization with a 2 + 1 dose schedule at a maximal coverage and close seroepidemiologic surveillance are necessary in order to draw definite conclusions, because of the potentially strong impact of very dynamic ecological factors present in our geopolitical area upon the agent-host interrelationship.