Immuno-persistence after the 4th and 5th dose of inactivated polio vaccines in school-aged children

Kathy Leung; Chrissy W K Pang; Tiffany H K Lo; Juan C Vargas-Zambrano; Céline Petit; Tommy T Y Lam; Eric H Y Lau; Joseph T Wu

doi:10.1016/j.cmi.2024.10.007

Immuno-persistence after the 4^th and 5^th dose of inactivated polio vaccines in school-aged children

Clin Microbiol Infect. 2024 Oct 12:S1198-743X(24)00489-0. doi: 10.1016/j.cmi.2024.10.007. Online ahead of print.

Authors

Kathy Leung¹, Chrissy W K Pang², Tiffany H K Lo³, Juan C Vargas-Zambrano⁴, Céline Petit⁵, Tommy T Y Lam², Eric H Y Lau², Joseph T Wu⁶

Affiliations

¹ WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; Laboratory of Data Discovery for Health Limited (D(2)4H), Hong Kong Science Park, Hong Kong SAR, China; The University of Hong Kong - Shenzhen Hospital, Shenzhen, China. Electronic address: ksmleung@hku.hk.
² WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; Laboratory of Data Discovery for Health Limited (D(2)4H), Hong Kong Science Park, Hong Kong SAR, China.
³ Laboratory of Data Discovery for Health Limited (D(2)4H), Hong Kong Science Park, Hong Kong SAR, China.
⁴ Global Medical Affairs, Sanofi, Lyon, France.
⁵ Global Immunology, Sanofi, Marcy-l'Etoile France.
⁶ WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; Laboratory of Data Discovery for Health Limited (D(2)4H), Hong Kong Science Park, Hong Kong SAR, China; The University of Hong Kong - Shenzhen Hospital, Shenzhen, China.

PMID: 39401679
DOI: 10.1016/j.cmi.2024.10.007

Abstract

Objective: This study aimed to assess the long-term persistence of neutralising antibodies (nAb) titres and seroprotection proportions after the 4^th and 5^th doses of inactivated polio vaccine (IPV).

Methods: Serum samples from 299 children in Hong Kong were collected and used to estimate the persistence of nAb titres and seroprotection proportions by neutralisation test.

Results: The mean nAb titres against polioviruses type 1, 2 and 3 (PV1, PV2 and PV3) one month after receiving the 4^th dose of IPV at 19 months of age were 2,068 (95% credible interval: 1,517 - 2,864), 4,705 (3,439 - 6,436) and 2,758 (1,894 - 4,086), but declined substantially in 4 years to 268 (222 - 325), 751 (630 - 900), and 411 (323 - 521), respectively. Administration of the 5^th dose of IPV restored nAb titres among children aged 6-7 years, and the decline in nAb titres was slightly slower with the estimated mean titres of 355 (272 - 462), 538 (427 - 681), and 548 (378 - 786) against PV1, PV2, and PV3 at 4 years post the 5^th dose. We estimated that the proportion of children who were seroprotected against PV1, PV2 and PV3 would drop below 90% at: (i) 8.2, 10.8, 8.7 years after the 4^th dose; and (ii) 11.6, 11.2, 11.0 years after the 5^th dose.

Conclusions: The results revealed the immuno-persistence after the 4th and 5th dose of IPV and highlighted the importance of completing immunization series to ensure high vaccination coverage, particularly among children in the developing countries affected by the COVID-19 pandemic.