Immunity to poliomyelitis in Victorians.
OBJECTIVE
In view of WHO's goal for poliomyelitis eradication by 2005 and the possible introduction of IPV into the Australian Standard Vaccination Schedule, this investigation was conducted to assess current immunity to poliomyelitis across the Victorian community.


METHODS
1,775 sera collected from three population samples within the Victorian community between 1990 and 1995 were tested for neutralising antibody titres against each poliovirus type in accordance with WHO recommended procedure.


RESULTS
In infants over three months and adults under 40 years, 76-100% of people in each age group were seropositive to all poliovirus types, with 90-100% seropositive to type I, 94-100% seropositive to type II and 80-97% seropositive to type III. Of the very small number of adults over 40 years tested (n = 13), 85% were seropositive to each of types I and II, and 62% to type III. 92% of vaccination histories taken and checked were confirmed, and reported immunisation rates were significantly below seropositive rates.


CONCLUSIONS
According to poliovirus antibody seroprevalence, current immunity to poliomyelitis appears sufficient for herd immunity. When compared with vaccination histones, significantly more people demonstrated immunity to poliomyelitis than the number who reported having been vaccinated against it, indicating the possible role of intestinal vaccine strain poliovirus spread in maintaining high immunity levels.


CONCLUSIONS
The current Australian Standard Vaccination Schedule has successfully provided protective levels of poliomyelitis immunity for the Victorian community in the absence of wild virus since at least 1972. This must be considered in assessing the future direction of Australia's poliomyelitis immunisation program.
Hogg
Katharine
K
Murdoch Children's Research Institute, Royal Children's Hospital, Department of Microbiology & Immunology, The University of Melbourne, Victoria.
Hogg
Geoff
G
Lester
Rosemary
R
Uren
Eric
E
D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006302:Health Services Research; D006801:Humans; D017589:Immunization Programs; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D009500:Neutralization Tests; D011051:Poliomyelitis / Q000276:immunology* / Q000517:prevention & control; D023321:Poliovirus Vaccines / Q000008:administration & dosage; D016036:Seroepidemiologic Studies; D014739:Victoria / Q000453:epidemiology
D000914:Antibodies, Viral; D023321:Poliovirus Vaccines