<prompt> Which of the following is not true about sabin vaccine?Three doses are given in primary immunizationThe doses are given at 4-6 weeks intervalGiven intramuscularlyContains all the 3 strains  <response>: The primary course of immunisation consists of 4 inoculations. Reference:Park;s textbook of preventive and social medicine,K.Park,23rd edition,page no:206. p 