Which of the following statements regarding live vaccines is false -
Ans. is 'a' i.e., Two live vaccines cannot be administered simultaneously Two live vaccines can be administered simultaneously. "When two live vaccines are required they should be given either simultaneously at different sites or with an interval of at least 3 weeks". Advantages of live vaccine o Live vaccines are more potent immunizing agents than killed vaccine because : - i) Live organisms multiply in the host and the resulting antigenic dose is larger than what is injected. ii) Live vaccines have all major and minor components. iii) Live vaccines engage ceain tissues of the body, e.g., intestinal mucosa by OPV. iv) Latent virus may persist and provides continous antigenic stimulation. o Immunization with live vaccines often .rovides for live Ion* immunit with a sing le dose and booster does are not required. The exception to this is OPV. Which needs three or more doses. o No need for adjuvant, as live vaccines are more potent antigens. o Also produce immunity at the natural site of infection e.g., in intestinal mucosa by OPV. Disadvantages of live vaccine o Cannot be given to immunocompromized person. o Must be properly stored to retain effectiveness --> Serious failure of measles and polio immunization have resulted from inadequate refrigeration prior to use. Also know o Live and killed vaccine can be given together. o Live vaccines should not normally be given for 12 weeks after an injection of normal human Ig and if a live vaccine has already been given, Human Ig injection should be deferred for 2 weeks.
Two live vaccines cannot be administered simultaneously
Booster doses are not required when live vaccines are administered
Single dose gives life long immunity
Live vaccine contains both major and minor antigens