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The COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused nations to adopt unprecedented control measures in order to curb its spread.As the first nation to respond, China's aggressive control measures appeared to have been effective in suppressing the first wave and keeping new cases under control. Here, we provide the historical context and details of China's public health response to COVID-19. We highlight the lessons and impact of the 2002-2003 SARS outbreak, which demonstrated the importance of transparency, surveillance and testing laboratories during an outbreak. We provide an overview of China's response strategy that was based on the principles of early detection, isolation, management and treatment and involved not only the largescale coordination of multiple governmental bodies but also grass-root community participation throughout the country. These community-based organizations conducted active surveillance for febrile cases and provided support for those in quarantine and communities in lockdown. Importantly, these broader measures were supported by digital technology, including the extensive use of internet-based platforms and mobile applications (APPs). While there have been no significant increases in case numbers since April, there is still much concern over a second wave, considering the resumption of work and school, the lifting of travel restrictions and the outbreaks occurring globally. Control measures has since been implemented by provincial authorities, which includes continued surveillance and rapid testing. Although China's strict control measures may not suit every nation, the principles of early detection and isolation continue to hold true and have been a cornerstone of the initial and ongoing response to the COVID-19.

Age‐associated immune changes and pre‐existing influenza immunity are hypothesized to reduce influenza vaccine effectiveness in older adults, although the contribution of each factor is unknown. Here, we constructed influenza‐specific IgG landscapes and determined baseline concentrations of cytokines typically associated with chronic inflammation in older adults (TNF‐α, IL‐10, IL‐6, and IFN‐γ) in 30 high and 29 low influenza vaccine responders (HR and LR, respectively). In a background of high H3 antibody titers, vaccine‐specific H3, but not H1, antibody titers were boosted in LRs to titers comparable to HRs. Pre‐vaccination concentrations of IL‐10 were higher in LRs compared with HRs and inversely correlated with titers of pre‐existing influenza antibodies. Baseline TNF‐α concentrations were positively correlated with fold‐increases in antibody titers in HRs. Our findings indicate that baseline inflammatory status is an important determinant for generating post‐vaccination hemagglutinin‐inhibition antibodies in older adults, and IgG responses can be boosted in the context of high pre‐existing immunity.