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BRIEF RESEARCH REPORT article

Front. Immunol.
Sec. Vaccines and Molecular Therapeutics
Volume 15 - 2024 | doi: 10.3389/fimmu.2024.1502598

Reduced durability of hybrid immunity to SARS-CoV-2 in immunocompromised children

Provisionally accepted
Youjia Zhong Youjia Zhong 1,2,3*Amuthavalli Kottaiswamy Amuthavalli Kottaiswamy 3Chen Xiang Ang Chen Xiang Ang 2Hui’ En Li Hui’ En Li 3Gaik Chin Yap Gaik Chin Yap 3Carina JX Tay Carina JX Tay 3Nurul Elyana Osman Nurul Elyana Osman 3Siti Namirah Roslan Siti Namirah Roslan 3Chee Wah Tan Chee Wah Tan 4Wee Chee Yap Wee Chee Yap 4Elizabeth Y Ang Elizabeth Y Ang 2Pauline PL Chan Ng Pauline PL Chan Ng 2,3Hui Kim Yap Hui Kim Yap 2,3Liangjian Lu Liangjian Lu 2Marion M Aw Marion M Aw 2,3S. Ventakesh Karthik S. Ventakesh Karthik 2Seng Hock Quak Seng Hock Quak 2Thuan Chong Quah Thuan Chong Quah 2Elizabeth H Tham Elizabeth H Tham 2,3Lynette P Shek Lynette P Shek 2,3Eng Eong Ooi Eng Eong Ooi 1,5,6
  • 1 Department of Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
  • 2 Khoo Teck Puat, National University Children’s Medical Institute (KTP-NUCMI), Singapore, Singapore
  • 3 Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, Singapore, Singapore
  • 4 Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, NUS, Singapore, Singapore, Singapore
  • 5 Department of Clinical Translational Research, Singapore General Hospital, Singapore, Singapore
  • 6 Viral Research and Experimental Medicine Centre, SingHealth Duke-NUS Academic Medical Centre, Singapore, Singapore

The final, formatted version of the article will be published soon.

    Background: In endemic COVID-19, immunocompromised children are vulnerable until vaccinated but the optimal primary vaccination regime and need for booster doses remains uncertain. Methods: We recruited 19 immunocompromised children (post-solid organ transplantation, have autoimmune disease or were on current or recent chemotherapy for acute lymphoblastic leukaemia), and followed them from the start of primary vaccination with BNT162b2 mRNA SARS-CoV-2 until 1-year postvaccination. We investigated the quality of vaccine immunogenicity, and longevity of hybrid immunity, in comparison to healthy children. Results: Immunocompromised children failed to produce T cell and memory B cell (MBC) responses reaching thresholds of protection after 2 doses; a third dose however improved both responses. Initially robust hybrid immunity demonstrated significantly more decline in T cell and MBC responses in immunocompromised compared to healthy children, to levels below the protective threshold by month 12. Discussion: Immunocompromised children may benefit from a 3-dose primary vaccination regime, with yearly or twice-yearly booster doses for sustained immunity.

    Keywords: Adaptive Immunity, COVID-19, memory B cells, T cells, Vaccine immunogenicity

    Received: 27 Sep 2024; Accepted: 29 Nov 2024.

    Copyright: © 2024 Zhong, Kottaiswamy, Ang, Li, Yap, Tay, Osman, Roslan, Tan, Yap, Ang, Chan Ng, Yap, Lu, Aw, Karthik, Quak, Quah, Tham, Shek and Ooi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Youjia Zhong, Department of Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, 169857, Singapore

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.