Influenza and Respiratory Virus Surveillance, Vaccine Uptake, and Effectiveness at a Time of Cocirculating COVID-19: Protocol for the English Primary Care Sentinel System for 2020-... oleh de Lusignan, Simon, Lopez Bernal, Jamie, Byford, Rachel, Amirthalingam, Gayatri, Ferreira, Filipa, Akinyemi, Oluwafunmi, Andrews, Nick, Campbell, Helen, Dabrera, Gavin, Deeks, Alexandra, Elliot, Alex J, Krajenbrink, Else, Liyanage, Harshana, McGagh, Dylan, Okusi, Cecilia, Parimalanathan, Vaishnavi, Ramsay, Mary, Smith, Gillian, Tripathy, Manasa, Williams, John, Victor, William, Zambon, Maria, Howsam, Gary, Nicholson, Brian David, Tzortziou Brown, Victoria, Butler, Christopher C, Joy, Mark, Hobbs, FD Richard