Omicron variants of SARS-CoV-2 are globally dominant and infection rates are very high in children. We measure immune responses following Omicron BA.1/2 infection in children aged 6-14 years and relate this to prior and subsequent SARS-CoV-2 infection or vaccination. Primary Omicron infection elicits a weak antibody response with poor functional neutralizing antibodies. Subsequent Omicron reinfection or COVID-19 vaccination elicits increased antibody titres with broad neutralisation of Omicron subvariants. Prior pre-Omicron SARS-CoV-2 virus infection or vaccination primes for robust antibody responses following Omicron infection but these remain primarily focussed against ancestral variants. Primary Omicron infection thus elicits a weak antibody response in children which is boosted after reinfection or vaccination. Cellular responses are robust and broadly equivalent in all groups, providing protection against severe disease irrespective of SARS-CoV-2 variant. Immunological imprinting is likely to act as an important determinant of long-term humoral immunity, the future clinical importance of which is unknown.
This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Dowell, A., Lancaster, T., Bruton, R., Ireland, G., Bentley, C., Sylla, P., Zuo, J., Scott, S., Jadir, A., Begum, J., Roberts, T., Stephens, C., Ditta, S., Shepherdson, R., Powell, A., Brent, A., Brent, B., Baawuah, F., Okike, I., Beckmann, J., Ahmad, S., Aiano, F., Garstang, J., Ramsay, M., Azad, R., Waiblinger, D., Willett, B., Wright, J., Ladhani, S. & Moss, P. 2023, 'Immunological imprinting of humoral immunity to SARS-CoV-2 in children', Nature Communications, 14, article no: 3845. https://doi.org/10.1038/s41467-023-39575-2