Kaliappan SP, Venugopal S, Giri S, Praharaj I, Karthikeyan AS, Babji S, John J, Muliyil J, Grassly N, Kang G. Factors determining anti-poliovirus type 3 antibodies among orally immunised Indian infants.
Vaccine 2016;
34:4979-4984. [PMID:
27566901 PMCID:
PMC5038128 DOI:
10.1016/j.vaccine.2016.08.032]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/03/2016] [Accepted: 08/11/2016] [Indexed: 01/13/2023]
Abstract
88.1% of 8454 children screened had protective antibodies to poliovirus serotype 3.
The number of tOPV doses received was the main determinant of seroprevalence.
Age, gender, residence and number of tOPV doses are associated with seroprevalence.
Background
Among the three poliovirus serotypes, the lowest responses after vaccination with trivalent oral polio vaccine (tOPV) are to serotype 3. Although improvements in routine immunisation and supplementary immunisation activities have greatly increased vaccine coverage, there are limited data on antibody prevalence in Indian infants.
Methods
Children aged 5–11 months with a history of not having received inactivated polio vaccine were screened for serum antibodies to poliovirus serotype 3 (PV3) by a micro-neutralisation assay according to a modified World Health Organization (WHO) protocol. Limited demographic information was collected to assess risk-factors for a lack of protective antibodies. Student’s t-test, logistic regression and multilevel logistic regression (MLR) model were used to estimate model parameters.
Results
Of 8454 children screened at a mean age of 8.3 (standard deviation [SD]-1.8) months, 88.1% (95% confidence interval (CI): 87.4–88.8) had protective antibodies to PV3. The number of tOPV doses received was the main determinant of seroprevalence; the maximum likelihood estimate yields a 37.7% (95% CI: 36.2–38.3) increase in seroprevalence per dose of tOPV. In multivariable logistic regression analysis increasing age, male sex, and urban residence were also independently associated with seropositivity (Odds Ratios (OR): 1.17 (95% CI: 1.12–1.23) per month of age, 1.27 (1.11–1.46) and 1.24 (1.05–1.45) respectively).
Conclusion
Seroprevalence of antibodies to PV3 is associated with age, gender and place of residence, in addition to the number of tOPV doses received. Ensuring high coverage and monitoring of response are essential as long as oral vaccines are used in polio eradication.
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