Effect of vaccine booster, vaccine type, and hybrid immunity on humoral and cellular immunity against SARS-CoV-2 ancestral strain and Omicron variant sublineages BA.2 and BA.5 among older adults with comorbidities: a cross sectional studyResearch in context
Carol Ho-Yan Fong,
Xiaojuan Zhang,
Lin-Lei Chen,
Rosana Wing-Shan Poon,
Brian Pui-Chun Chan,
Yan Zhao,
Carlos King-Ho Wong,
Kwok-Hung Chan,
Kwok-Yung Yuen,
Ivan Fan-Ngai Hung,
Jacqueline Kwan Yuk Yuen,
Kelvin Kai-Wang To
Affiliations
Carol Ho-Yan Fong
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
Xiaojuan Zhang
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
Lin-Lei Chen
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
Rosana Wing-Shan Poon
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China; Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China
Brian Pui-Chun Chan
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
Yan Zhao
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
Carlos King-Ho Wong
Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China; Department of Family Medicine and Primary Care, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China; Laboratory of Data Discovery for Health (D24H), Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
Kwok-Hung Chan
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China; Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
Kwok-Yung Yuen
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China; Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China; Department of Clinical Microbiology and Infection Control, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China; Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China
Ivan Fan-Ngai Hung
Infectious Diseases Division, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China
Jacqueline Kwan Yuk Yuen
Division of Geriatric Medicine, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China; Corresponding author. Division of Geriatric Medicine, Department of Medicine, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.
Kelvin Kai-Wang To
State Key Laboratory for Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China; Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China; Department of Clinical Microbiology and Infection Control, The University of Hong Kong-Shenzhen Hospital, Shenzhen, China; Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China; Corresponding author. Department of Microbiology, 19th Floor, Block T, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China.
Summary: Background: Vaccination reduces COVID-19-related hospitalization among older adults. However, how SARS-CoV-2 infection and vaccine regimens affect vaccine-elicited immunity remain unclear. Methods: This is a cross-sectional study recruiting adults aged ≥70 years with comorbidities in Hong Kong. Demographic and clinical information were collected using a questionnaire. Neutralizing antibody (nAb) titers (against ancestral and Omicron strains) and SARS-CoV-2-specific T cell response were analyzed according to infection and vaccination status. Multivariable regression analysis was performed to assess the associations of BNT162b2 and booster doses with higher nAb titers, with adjustment for comorbidities. Findings: In July 2022, 101 patients were recruited, of whom 25 (24%) had previous infection. Overall, the geometric mean titer (GMT) of BA.5 nAb was 2.8-fold lower than that against BA.2 (P < 0.0001). The ancestral strain and BA.2 titers were higher for the 3-4-dose-BNT162 group than the 2-dose-BNT162b2 group. Non-infected individuals in the 3-4-dose-CoronaVac group had a more robust T cell response than the 2-dose-CoronaVac group (P = 0.0181), but there was no significant difference between the 2-dose-BNT162b2 and 3-4-dose-BNT162b groups. Patients who had heterologous CoronaVac-BNT162b2 prime-boost regimen had 3.22-fold higher BA.5 nAb titers than those who were primed/boosted with CoronaVac (P = 0.0207). Patients with hybrid immunity had higher Omicron nAb titers than those with vaccine-only immunity. Multivariable analysis showed that BNT162b2 and booster doses were independently associated with higher ancestral strain nAb titers. Interpretation: Our data support the use of booster doses for older adults with or without prior infection. Non-infected individuals primed with CoronaVac will benefit from heterologous mRNA vaccine booster. Funding: Richard and Carol Yu, May Tam Mak Mei Yin, The Shaw Foundation Hong Kong, Michael Tong, Marina Lee, Government Consultancy Service (See acknowledgements for full list).
