. 2024 Apr 25;29(17):2400199. doi: 10.2807/1560-7917.ES.2024.29.17.2400199

Table 2. Genetic characterisation of the influenza A(H1N1)pdm09 strains from the most severely affected children admitted to Meyer Children’s Hospital, Florence, Italy, December 2023–January 2024 (n = 3).

Patient	Virus lineage	Clade	Identified amino acid substitutions on haemagglutinin (HA) gene from PB2A/Victoria/4897/2022(H1N1)
PICU 1	FluA(H1N1)pdm09	6B.1A.5a.2a	N55D, T137A, S154P, R159K, K186Q, A233T, R240Q, E277D, A294T, D373E, H468N, K497R
PICU 2	FluA(H1N1)pdm09	6B.1A.5a.2a	R159K, A233T, R240Q, E277D, A294T, D373E, H416R, H468N, I550L
PICU 3	FluA(H1N1)pdm09	6B.1A.5a.2a	T137A, S154P, R159K, K186Q, A233T, R240Q, E277D, A294T, D373E, H468N

All mutations are not known to alter the virulence of the virus, cause strong drug resistance or reverse the effects of the premature STOP codon in the PB1-F2 gene of pandemic H1N1 (https://flusurver.bii.a-star.edu.sg).

Table 2. Genetic characterisation of the influenza A(H1N1)pdm09 strains from the most severely affected children admitted to Meyer Children’s Hospital, Florence, Italy, December 2023–January 2024 (n = 3).

Table 2. Genetic characterisation of the influenza A(H1N1)pdm09 strains from the most severely affected children admitted to Meyer Children’s Hospital, Florence, Italy, December 2023–January 2024 (n = 3).