<prompt> All are true about measles except-Incubation period is 10-14 daysSecondary attack rate is 30-40Sub cutaneous vaccine is availableVaccine is live attenuated  <response>: MEASLES:- An acute highly infectious disease of childhood caused by a specific virus of group myxovirus. Clinically characterised by fever and catarrhal symptoms of the upper respiratory tract coryza,cough, followed by a typical rash. Incubation period-10 days from exposure to onset of fever and 14 days of appearance of rash. Secondary attack rate-infection confers life long immunity as there is only one antigenic type. Vaccine- live attenuated subcutaneous vaccine. Reference: park;s textbook of preventive and social medicine, 23rd edition, pg no.149 