This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'Efficiency of measles vaccine - \nSelect and explain. \nA. 55%, B. 75%, C. 85%, D. 100%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: <p>MEASLES VACCINE:- Live attenuated vaccine Person to person transmission of measles vaccine strains has never been documented. Freeze dried product. In the year 2010, the worlds two most populous countries made promising advances in measles control: china held the largest ever SIA , vaccinating > 103 million children and India staed implementation of a 2 dose vaccination strategy. 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. Efficiency-55% 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}</p>', 'role': 'assistant'}]