Pertussis Antibody Levels Among Immunized Children Aged Between 8 To15yrs

Abstract

I N T R O D U C T I O N newline1 newlineINTRODUCTION newlinePertussis is still a major public health concern. Pertussis newlinecases in India in 2016 were 37274.Though India pertussis cases newlinefluctuated substantially in recent years,it tended to increase through newline1997 to 2016, despite high vaccination coverage, yearly incidence newlinecontinues to increase and mortality in children 8 -12years of age has newlinebeen increasing. Protection from pertussis is not life -long, but newlinerestricted to a period of 5 8 years, after natural infection, as well as newlineafter vaccination . 1 This waning of immunity explains the shift of newlinethe incidence peak from school-age to adolescents/ adults, and the newlinespread from these subjects to infants and young children, still newlineunvaccinated or not fully vaccinated .The global incidence of newlinepertussis declined to very low level with the advent of whole -cell newlinepertussis (wP) vaccines by the 1970s. However, in the 1990s, safety newlineconcerns prompted a switch from wP to acellular-pertussis (aP) newlinevaccines in most of the developed countries. Since 2009, large newlineoutbreaks of pertussis are regularly reported from many newlineindustrialized countries employing aP vaccines despite having very newlinehigh vaccination coverage. 2 ,3 Outbreaks have also been reported newlinefrom countries using wP vaccines like the one reported recently newlinefrom Khairpur District of Sindh province of Pakistan. 4 However, newlineanother study from Pakistan conducted between 2005 and 2009 newlinefound that B. parapertussis was responsible for the pertussis newlineoutbreak against which the wP vaccines had shown little efficacy. 5 newlineI N T R O D U C T I O N newline2 newlineOccurrences of pertussis in spite of vaccination has raised newlinequestion about the protection offered by whole cell pertussis newlinevaccine and the need for administering a booster dose at 10 years of newlineage along with TT booster. There is no Indian study on the waning newlineimmunity of whole cell pertussis vaccine over a period of time, newlinehence we recommend children with low IgG bordetlla pertussis newlineantibody titre to get a booster dose of acellular pertussis vaccine . newline