Impact of Delta Variant and Vaccination on SARS-CoV-2 Secondary Attack Rate Among Household Close Contacts oleh Oon Tek Ng, Vanessa Koh, Calvin J Chiew, Kalisvar Marimuthu, Natascha May Thevasagayam, Tze Minn Mak, Joon Kiat Chua, Shannen Si Hui Ong, Yong Kai Lim, Zannatul Ferdous, Alifa Khairunnisa bte Johari, Mark I-Cheng Chen, Sebastian Maurer-Stroh, Lin Cui, Raymond Tzer Pin Lin, Kelvin Bryan Tan, Alex R Cook, Prof. Yee-Sin Leo, Prof. Vernon JM Lee