Widely heterogeneous humoral and cellular immunity after mild SARS-CoV-2 infection in a homogeneous population of healthy young men
Nina Le Bert, Wan Ni Chia, Wei Yee Wan, Alvin Kuo Jing Teo, Samuel Zeng-Rong Chong, Nicole Tan, Doreen Soek Chin Tan, Adeline Chia, Iain Beehuat Tan, Kamini Kunasegaran, Qin Chua, Mohammad Yazid Abdad, Angus Jun Jie Ng, Shawn Vasoo, Julian Xiao-Li Ang, Mao Sheng Lee, Louisa Sun, Jinyan Fang, Feng Zhu, Alex R. Cook, Tar Choon Aw, Jingxiang Huang, Clarence C. Tam, Fong Sin Lee, Hannah Clapham, Enan Jun-Kang Goh, Monica Socheata Suor Peou, Shiow Pin Tan, Siew Kim Ong, Lin‐Fa Wang, Antonio Bertoletti, Li Yang Hsu, Biauw Chi Ong
Abstract
BACKGROUND: We studied humoral and cellular responses against SARS-CoV-2 longitudinally in a homogeneous population of healthy young/middle-aged men of South Asian ethnicity with mild COVID-19. METHODS: = 311). Three commercial assays were used to detect anti-nucleoprotein (NP) and neutralizing antibodies. T cell response specific for Spike, Membrane and NP SARS-CoV-2 proteins was tested in 85 patients at day 105, 180, and 280. RESULTS: All serological tests displayed different kinetics of progressive antibody reduction while the frequency of T cells specific for different structural SARS-CoV-2 proteins was stable over time. Both showed a marked heterogeneity of magnitude among the studied cohort. Comparatively, cellular responses lasted longer than humoral responses and were still detectable nine months after infection in the individuals who lost antibody detection. Correlation between T cell frequencies and all antibodies was lost over time. CONCLUSION: Humoral and cellular immunity against SARS-CoV-2 is induced with differing kinetics of persistence in those with mild disease. The magnitude of T cells and antibodies is highly heterogeneous in a homogeneous study population. These observations have implications for COVID-19 surveillance, vaccination strategies, and post-pandemic planning.