Implications of and lessons learned from external assurance of eight influenza diagnostics in China.

•Using genetic engineering technology, VLPs encapsulating the 37 target genes of 8 influenza viruses were generated.•The panel was distributed to 35 laboratories in mainland China to investigate the proficiency of the 16 assays for influenza molecular detection.•The assay for N2 gene showed good results in A(H3N2) identification while poor for A(H9N2).•Compared to influenza viruses and vacuum-dried RNA samples, the VLP is a good alternative specimen type for EQA.