MEASLES VACCINE:- Live attenuated vaccine Person to person transmission of measles vaccine strains has never been documented. Freeze dried product. Before use ,the lyophilised vaccine is reconstituted with sterile diluent. Diluent must be cooled before reconstitution but it should not be freezed.After reconstitution , vaccine must be stored in dark at 2-8 degree celcius and used within 4 hrs. Each dose if 0.5 ml contains > 1000 viral infective units of vaccine strain. Measles vaccine may also contain sorbitol and hydrolysed gelatin as stabilizers and neomycin but it doesn&;t have thiomersal. It is thermolabile. Age-before 9 months.The age can be lowered to 6 months if there is measles outbreak in community.For infants immunised between 6 and 9 months,second dose administered as soon as possible after the child reaches 9 months provided that at least 4 weeks have elapsed since the last dose. Route-subcutaneous/intramuscular. Immune response- both humoral and cellular. Contraindications- High fever,pregnancy, history of anaphylactic reaction to vaccine components, immunocompromised individuals, leukemia, lymphoma,severe HIV( early stage of HIV is not a contraindication), treatment with steroids, antimetabolites and serious malignancy. Adverse reactions:- TSS-toxic shock syndrome. Occurs when measles vaccine is contaminated or when the same l is used more than once on same day / next day. The vaccine should not be used after 4 hrs of reconstitution. Symptoms of TSS : severe watery diarrhoea, vomiting, high fever repoed within few hours after vaccination. TSS is totally preventable and reflects poor quality of immunisation. {Reference: park&;s textbook of preventive and social medicine, 23rd edition, pg no.149}