Lower vaccine-acquired immunity in the elderly population following two-dose BNT162b2 vaccination is alleviated by a third vaccine dose

• Main Authors: Renia, Laurent, Goh, Yun Shan, Rouers, Angeline, Bert, Nina Le, Chia, Wan Ni, Chavatte, Jean-Marc, Fong, Siew-Wai, Chang, Zi Wei, Zhuo, Nicole Ziyi, Tay. Matthew Zirui, Chan, Yi-Hao, Tan Chee Wah, Yeo, Nicholas Kim-Wah, Amrun, Siti Naqiah, Huang, Yuling, Wong, Joel Xu En, Hor, Pei Xiang, Loh, Chiew Yee, Wang, Bei, Ngoh, Eve Zi Xian, Salleh, Siti Nazihah Mohd Salleh, Carissimo, Guillaume, Dowla, Samanzer, Lim, Alicia Jieling, Zhang, Jinyan, Lim, Joey Ming Er, Wang, Cheng-I., Ding, Ying, Pada, Surinder, Sun, Lousia Jin, Somani, Jyoti, Lee, Eng Sing, Ong, Desmond Luan Seng, Leo, Yee-Sin, MacAry, Paul A., Lin, Raymond Tzer Pin, Wang, Lin-Fa, Ren, Ee Chee, Lye, David C., Bertoletti, Antonio, Young, Barnaby Edward, Ng, Lisa F. P., Ruesta, Torres Anthony, Neo, Vanessa, Chen, Wendy Yehui, Goh, Estelle Yi Wei, Ong, Alice Soh Meoy, Chua, Adeline Chiew Yen, Nguee, Samantha Yee Teng, Tan, Yong Jie, Tang, Weiyi
• Other Authors: Lee Kong Chian School of Medicine (LKCMedicine)
• Format: Article
• Language: English
• Published: 2023
• Subjects: Science::Biological sciences; Recombinant Vaccine; Prevention and Control
• Online Access: https://hdl.handle.net/10356/171167
• Institution: Nanyang Technological University

Understanding the impact of age on vaccinations is essential for the design and delivery of vaccines against SARS-CoV-2. Here, we present findings from a comprehensive analysis of multiple compartments of the memory immune response in 312 individuals vaccinated with the BNT162b2 SARS-CoV-2 mRNA vaccine. Two vaccine doses induce high antibody and T cell responses in most individuals. However, antibody recognition of the Spike protein of the Delta and Omicron variants is less efficient than that of the ancestral Wuhan strain. Age-stratified analyses identify a group of low antibody responders where individuals ≥60 years are overrepresented. Waning of the antibody and cellular responses is observed in 30% of the vaccinees after 6 months. However, age does not influence the waning of these responses. Taken together, while individuals ≥60 years old take longer to acquire vaccine-induced immunity, they develop more sustained acquired immunity at 6 months post-vaccination. A third dose strongly boosts the low antibody responses in the older individuals against the ancestral Wuhan strain, Delta and Omicron variants.