Not a strategy for measles elimination -

Ans. is 'a' i.e., Mop up: Vaccinate kids left with routine vaccination o WHO's measles elimination strategy comprises a three part vaccination strateev. i.e.i) Catch-upOne-time, nationwide vaccination campaign targeting usually all children aged 9 months to 14 years regardless of history of measles disease or vaccination status.ii) Keep-up -Routine services aimed at vaccinating more than 95% of each successive birth cohort.in) Follow-up -Subsequent nationwide vaccination campaign conducted every' 2-4 years targeting usually all children bom after catch-up campaign.o The priorties of countries persuing measles control includeImprove routine vaccination coverage level to at least 90%.Active coverage of more than 90% in catch-up and follow-up campaigns or active coverage of more than 90% with routine second dose of measles vaccine.Establish case - based surveillance with laboratory confirmation of suspected cases and virus isolation from all chains of transmission.Conduct supplementary vaccination campaign together with administration of vitamin 'A' in high risk areas.o In India, measles is a major cause of morbidity' and a significant contributor to childhood mortality. Prior to the immunization programme, cyclical increase in the incidence of measles were recorded every' third year. With the increase in immunization coverage levels, the intervals between cyclic peaks has increased and the intensity' of the peak minimized.o Epidemic of measles occur ifproportion of susceptible children is > 40%o If measles is introduced in a virgin community, it infects > 90% of children,o Eradication of measles requires vaccine coverage >96%