<prompt> The most effective vaccine is -TTOPVB.C.GMeasles  <response>: .most effective vaccine is the live attenuated vaccines for measles.it is presented as afreeze dried product.0.5 ml contains more than 1000 vral infective units of the vaccine strain.uually given after 9 months of age along with vit A prophylaxis as per national immunisation schedule. ref:park;s textbook,ed 22,pg no 140 