<prompt> After two doses of vaccination against plague, the immunity will last for -Six monthsOne yearEighteen monthsTwenty-four months  <response>: - the plaque vaccine is killed vaccine. - two doses of 0.5 1 ml given subcutaneously at interval of 7-14 days. - immunity sta 5-7 days after inoculation and lasts for 6 months. Reference : Parks textbook of preventive and social medicine, 23rd edition, pg no:296 p 