Poliovirus antibodies following two rounds of campaigns with a type 2 novel oral poliovirus vaccine in Liberia: a clustered, population-based seroprevalence survey.

Abstract

BACKGROUND:

Novel oral poliovirus vaccine type 2 (nOPV2) was administered in Liberia in response to an outbreak of circulating vaccine-derived poliovirus type 2 (cVDPV2) in 2021. We conducted a serological survey of polio antibodies after two national campaigns with nOPV2.

METHODS:

This clustered, cross-sectional, population-based seroprevalence survey was conducted in children aged 0-59 months, more than 4 weeks after the second nOPV2 vaccination round. We used a clustered sampling method in four geographical regions of Liberia, followed by a simple random sampling of households. One eligible child was randomly selected per household. Dried blood spot specimens were taken and vaccination history was recorded. The antibody titres against all three poliovirus serotypes were assessed using standard microneutralisation assays done at the US Centers for Disease Control and Prevention in Atlanta, GA, USA.

FINDINGS:

Analysable data were obtained from 436 (87%) of 500 enrolled participants. Of these, 371 (85%) children were reported via parental recall to have received two nOPV2 doses, 43 (10%) received one dose, and 22 (5%) received no doses. The seroprevalence against type 2 poliovirus was 38·3% (95% CI 33·7-43·0; 167 of 436 participants). No significant difference was observed between type 2 seroprevalence in children aged 6 months or older who were reported to have received two doses of nOPV2 (42·1%, 95% CI 36·8-47·5; 144 of 342), one dose (28·0%, 12·1-49·4; seven of 25), or no doses (37·5%, 8·5-75·5; three of eight; p=0·39). The seroprevalence against type 1 was 59·6% (54·9-64·3; 260 of 436), and the seroprevalence against type 3 was 53·0% (48·2-57·7; 231 of 436).

INTERPRETATION:

Unexpectedly, the data showed low type 2 seroprevalence after two reported doses of nOPV2. This finding is probably affected by the lower oral poliovirus vaccine immunogenicity previously demonstrated in resource-limited settings, with high prevalence of chronic intestinal infections in children and other factors discussed herein. Our results provide the first assessment of nOPV2 performance in outbreak response in the African region.

FUNDING:

WHO and Rotary International.

• Authors: Stephen B Kennedy, Grace R Macklin, Gloria Mason Ross, Rocio Lopez Cavestany, Richelot A Moukom, Kathryn A V Jones, Bernardo A Mainou, Moses B F Massaquoi, Mark W S Kieh, Ondrej Mach
• Journal: The Lancet. Global health (Lancet Glob Health) Vol. 11 Issue 6 Pg. e917-e923 (06 2023) ISSN: 2214-109X [Electronic] England
• PMID: 37202026 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 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.

Chemical References

• Poliovirus Vaccine, Oral
• Antibodies, Viral

Topics

• Child
• Humans
• Infant
• Poliovirus Vaccine, Oral
• Poliovirus
• Seroepidemiologic Studies
• Cross-Sectional Studies
• Liberia (epidemiology)
• Poliomyelitis (epidemiology, prevention & control)
• Antibodies, Viral