Immunogenicity to SARS-CoV-2 Omicron variant among school-aged children with 2-dose of inactivated SARS-CoV-2 vaccines followed by BNT162b2 booster
Author
Chantasrisawad N, Puthanakit T, Kornsitthikul K, Jaru-Ampornpan P, Tawan M, Matapituk P, Sophonphan J, Anugulruengkitt S, Tangsathapornpong A, Katanyutanon A, Team KSTKS
Chulalongkorn University; Chulalongkorn University; Chulalongkorn University; National Science & Technology Development Agency - Thailand; National Center Genetic Engineering & Biotechnology (BIOTEC); Thammasat University; Ministry of Public Health - Thailand
Type
Article
Source Title
VACCINE: X
Year
2022
Volume
12
Open Access
gold, Green Published
Publisher
ELSEVIER
DOI
10.1016/j.jvacx.2022.100221
Format
PDF
Abstract
Background: A primary series of 2-dose SARS-CoV-2 vaccines based on an ancestral strain generate inad-equate neutralizing antibodies against the SARS-CoV-2 Omicron variant. This study aimed to describe the immune response from giving healthy school-aged children who previously received 2 inactivated vac-cines an mRNA BNT162b2 booster.Methods: Healthy children aged 5-11 years who received 2 doses of CoronaVac or Covilo were enrolled and received 10 lg BNT162b2 intramuscularly. Neutralizing antibody against Omicron variant was mea-sured at pre-booster and 14-21 days post-booster by surrogate virus neutralization test (sVNT, %inhibi-tion) and pseudovirus neutralization test (pVNT, ID50). Antibody responses were compared with a parallel cohort of children who received 2 doses of BNT162b2 3 weeks apart.Results: From April to May 2022, 59 children with a mean age (SD) of 8.5 years (1.7) were enrolled: 20 CoronaVac and 39 Covilo recipients. The median interval from the primary series was 49 days (IQR 33-51). After booster, the geometric means (GMs) of sVNT and pVNT were 72.2 %inhibition (95 %CI 67.2-77.6) and 499 (95 %CI 399-624), respectively. The proportion of children with sVNT against Omicron strain >= 68 %inhibition increased from none to 70.2 %. The geometric mean ratio (GMR) of sVNT and pVNT compared with a parallel cohort were 4.3 and 12.2, respectively. The GMR of sVNT and pVNT between children who received booster dose at >6-week interval were 1.2 (95 %CI 1.1-1.3). and 1.8 (95 %CI 1.2-2.7) compared with 4-6 weeks interval.Conclusion: A regimen of 2-dose of inactivated vaccine followed by BNT162b2 booster dose elicited high neutralizing antibody against the Omicron variants in healthy school-aged children.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
