Robust antibody responses in 70–80-year-olds 3 weeks after the first or second doses of Pfizer/BioNTech COVID-19 vaccine, United Kingdom, January to February 2021 Subbarao, Sathyavani and Warrener, Lenesha A and Hoschler, Katja and Perry, Keith R and Shute, Justin and Whitaker, Heather and O’Brien, Michelle and Baawuah, Frances and Moss, Paul and Parry, Helen and Ladhani, Shamez N and Ramsay, Mary E and Brown, Kevin E and Amirthalingam, Gayatri, Eurosurveillance, 26, 2100329 (2021), https://doi.org/10.2807/1560-7917.ES.2021.26.12.2100329