Fig. 1From: Phylogenetic analysis of HA and NA genes of influenza A viruses in immunosuppressed inpatients in Beijing during the 2018–2020 influenza seasonsDistribution of influenza viruses in northern China. The data were from weekly data of Influenza Laboratory Surveillance Network during April 2018 to May 2020. Red is A(H1N1)pdm09, green is influenza H3N2, and blue is influenza BBack to article page