What is MMR vaccine is a type of: September 2009, March 2013 and explain in detail?
Ans. C: Live attenuated vaccine The MMR vaccine is an immunization shot against measles, mumps and rubella (also called German measles). It was first developed by Maurice Hilleman in the late 1960s The vaccine is a mixture of three live attenuated viruses. The MMR vaccine is administered by a subcutaneous injection. In the case of live vaccines, immunization is generally achieved with a single dose. The exception is polio vaccine which needs three or more doses. As per Indian Academy of Paediatrics, the vaccine is administered once to children around the age of 15 months. Few countries advocates a second dose also before staing of school (i.e. age 4/5). The second dose is not a booster; it is a dose to produce immunity in the small number of persons (2-5%) who fail to develop measles immunity after the first dose. An inactivated vaccine (or killed vaccine) consists of virus paicles which are grown in culture and then killed using a method such as heat or formaldehyde Types include: - Viral: polio vaccine (Salk vaccine) and influenza vaccine - Bacterial: typhoid vaccine, cholera vaccine, plague vaccine, and peussis vaccine Examples of live attenuated vaccines include: - Viral: polio vaccine (Sabin vaccine), measles vaccine, mumps vaccine, rubella vaccine, chicken pox vaccine, yellow fever vaccine, and nasal-spray flu vaccine. - Bacterial: BCG vaccine, typhoid vaccine A toxoid is a bacterial toxin (usually an exotoxin) whose toxicity has been weakened or suppressed either by chemical (formalin) or heat treatment, while other propeies, typically immunogenicity, are maintained. Toxoids are used in vaccines as they induce an immune response to the original toxin or increase the response to another antigen. For example, the tetanus toxoid (derived from the tetanospasmin produced by Clostridium tetani and causing tetanus) and diphtheria toxoid.