Persistence of immunity following a single dose of inactivated poliovirus vaccine: a phase 4, open label, non-randomised clinical trial.

Autor:	Sharma AK; Department of Pediatrics, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal., Verma H; WHO, Geneva, Switzerland., Estivariz CF; Centers for Disease Control and Prevention, Atlanta, GA, USA., Bajracharaya L; Department of Pediatrics, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal., Rai G; Department of Pediatric Medicine, Kanti Children's Hospital, Kathmandu, Nepal., Shah G; Department of Pediatrics, Patan Hospital, Patan Academy of Health Sciences, Kathmandu, Nepal., Sherchand J; Department of Microbiology, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal., Jones KAV; Centers for Disease Control and Prevention, Atlanta, GA, USA., Mainou BA; Centers for Disease Control and Prevention, Atlanta, GA, USA., Chavan S; Centers for Disease Control and Prevention, Atlanta, GA, USA., Jeyaseelan V; WHO, Geneva, Switzerland., Sutter RW; WHO, Geneva, Switzerland. Electronic address: rolandsutter@gmail.com., Shrestha LP; Department of Pediatrics, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal.
Jazyk:	angličtina
Zdroj:	The Lancet. Microbe [Lancet Microbe] 2023 Nov; Vol. 4 (11), pp. e923-e930. Date of Electronic Publication: 2023 Sep 26.
DOI:	10.1016/S2666-5247(23)00215-X
Abstrakt:	Background: The polio eradication endgame required the withdrawal of Sabin type 2 from the oral poliovirus vaccine and introduction of one or more dose of inactivated poliovirus vaccine (IPV) into routine immunisation schedules. However, the duration of single-dose IPV immunity is unknown. We aimed to address this deficiency. Methods: In this phase 4, open-label, non-randomised clinical trial, we assessed single-dose IPV immunity. Two groups of infants or children were screened: the first group had previously received IPV at 14 weeks of age or older (previous IPV group; age >2 years); the second had not previously received IPV (no previous IPV group; age 7-12 months). At enrolment, all participants received an IPV dose. Children in the no previous IPV group received a second IPV dose at day 30. Blood was collected three times in each group: on days 0, 7, and 30 in the previous IPV group and on days 0, 30, and 37 in the no previous IPV group. Poliovirus antibody was measured by microneutralisation assay. Immunity was defined as the presence of a detectable antibody or a rapid anamnestic response (ie, priming). We used the χ 2 to compare proportions and the Mann-Whitney U test to assess continuous variables. To assess safety, vaccinees were observed for 30 min, caregivers for each participating child reported adverse events after each follow-up visit and were questioned during each follow-up visit regarding any adverse events during the intervening period. Adverse events were recorded and graded according to the severity of clinical symptoms. The study is registered with ClinicalTrials.gov, NCT03723837. Findings: From Nov 18, 2018, to July 31, 2019, 502 participants enrolled in the study, 458 (255 [65%] boys and 203 [44%] girls) were included in the per protocol analysis: 234 (93%) in the previous IPV group and 224 (90%) in the no previous IPV group. In the previous IPV group, 28 months after one IPV dose 233 (>99%) of 234 children had persistence of poliovirus type 2 immunity (100 [43%] of 234 children were seropositive; 133 [99%] of 134 were seronegative and primed). In the no previous IPV group, 30 days after one IPV dose all 224 (100%) children who were type 2 poliovirus naive had seroconverted (223 [>99%] children) or were primed (one [<1%]). No adverse events were deemed attributable to study interventions. Interpretation: A single IPV dose administered at 14 weeks of age or older is highly immunogenic and induces nearly universal type 2 immunity (seroconversion and priming), with immunity persisting for at least 28 months. The polio eradication initiative should prioritise first IPV dose administration to mitigate the paralytic burden caused by poliovirus type 2. Funding: WHO and Rotary International. Competing Interests: Declaration of interests We declare no competing interests. (© 2023 World Health Organization. Published by Elsevier Ltd. All rights reserved. This is an Open Access article published under the CC BY-NC-ND 3.0 IGO license which permits users to download and share the article for non-commercial purposes, so long as the article is reproduced in the whole without changes, and provided the original source is properly cited. This article shall not be used or reproduced in association with the promotion of commercial products, services or any entity. There should be no suggestion that WHO endorses any specific organisation, products or services. The use of the WHO logo is not permitted. This notice should be preserved along with the article's original URL.)
Databáze:	MEDLINE
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