Predominance of influenza virus A(H3N2) 3C.2a1b and A(H1N1)pdm09 6B.1A5A genetic subclades in the WHO European Region, 2018–2019. Issue 35 (31st July 2020)

• Record Type: Journal Article
• Authors: Melidou, Angeliki; Hungnes, Olav; Pereyaslov, Dmitriy; Adlhoch, Cornelia; Segaloff, Hannah; Robesyn, Emmanuel; Penttinen, Pasi; Olsen, Sonja J.; Redlberger-Fritz, Monika; Popow-Kraupp, Therese; Hasibra, Iris; Simaku, Artan; Thomas, Isabelle; Barbezange, Cyril; Dedeić-Ljubović, Amela; Rodić-Vukmir, Nina; Korsun, Neli; Angenova, Svetla; Draženović, Vladimir; Koliou, Maria; Pieridou, Despo; Havlickova, Martina; Nagy, Alexander; Trebbien, Ramona; Galiano, Monica; Thompson, Catherine; Ikonen, Niina; Haveri, Anu; Behillil, Sylvie; Enouf, Vincent; Valette, Martine; Lina, Bruno; Gavashelidze, Mari; Machablishvili, Ann; Gioula, Georgia; Exindari, Maria; Kossyvakis, Athanasios; Mentis, Andreas; Dürrwald, Ralf; Zsuzsanna, Molnar; Monika, Rozsa; Löve, Arthur; Erna, Gudrun; Dunford, Linda; Fitzpatrick, Sarah; Castrucci, Maria Rita; Puzelli, Simona; Sagymbay, Altynay; Nussupbayeva, Gaukhar; Zamjatina, Natalija; Pakarna, Gatis; Griskevičius, Algirdas; Skrickiene, Asta; Fournier, Guillaume; Mossong, Joel; Melillo, Jackie; Zahra, Graziella; Meijer, Adam; Fouchier, Ron; McCaughey, Conall; O'Doherty, Mark; Bragstad, Karoline; Guiomar, Raquel; Pechirra, Pedro; Apostol, Mariana; Alina, Druc; Lazar, Mihaela; Maria, Cherciu Carmen; Komissarov, Andrey; Burtseva, Elena; Gunson, Rory N.; Shepherd, Samantha; Tichá, Elena; Staronova, Edita; Prosenc, Katarina; Berginc, Nataša; Pozo, Francisco; Casas, Inmaculada; Brytting, Mia; Wiman, Åsa; Gonçalves, Ana Rita; Demchyshyna, Iryna; Mironenko, Alla; Moore, Catherine; Cottrell, Simon;
• Is Part Of: Vaccine. Volume 38:Issue 35(2020)
• Page Start: 5707
• Page End: 5717
• Publication Date: 2020-07-31
• Subjects: Influenza -- Surveillance -- Europe -- Genetic -- Antigenic -- Vaccine; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2020.06.031
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Co-circulation of different clades/subclades of influenza A viruses in 2018/2019 in the Region. Most circulating A(H1N1)pdm09 viruses (6B.1A) carried S183P in hemagglutinin. Genetically heterogeneous A(H3N2) viruses, with co-circulation of clades 3C.2a and 3C.3a. Antigenically distinct A(H3N2) clade 3C.3a viruses were increasingly detected until 02/2019 and then decreased. Co-circulation of genetically and antigenically diverse A(H3N2) strains challenges vaccine strain selection. Abstract: Background: The 2018/2019 influenza season in the WHO European Region was dominated by influenza A (H1N1)pdm09 and (H3N2) viruses, with very few influenza B viruses detected. Methods: Countries in the European Region reported virus characterization data to The European Surveillance System for weeks 40/2018 to 20/2019. These virus antigenic and genetic characterization and haemagglutinin (HA) sequence data were analysed to describe and assess circulating viruses relative to the 2018/2019 vaccine virus components for the northern hemisphere. Results: Thirty countries reported 4776 viruses characterized genetically and 3311 viruses antigenically. All genetically characterized A(H1N1)pdm09 viruses fell in subclade 6B.1A, of which 90% carried the amino acid substitution S183P in the HA gene. Antigenic data indicated that circulating A(H1N1)pdm09 viruses were similar to the 2018/2019 vaccine virus. Genetic data showed that A(H3N2) viruses mostly fell in clade 3C.2a (75%) and 90% of which were subclade 3C.2a1b. A lower proportion fell in clade 3C.3a (23%) and were antigenically distinct from the vaccine virus. All B/Victoria viruses belonged to clade 1A; 30% carried a double amino acid deletion in HA and were genetically and antigenically similar to the vaccine virus component, while 55% carried a triple amino acid deletion or no deletion in HA; these were antigenically distinct from each other and from the vaccine component. All B/Yamagata viruses belonged to clade 3 and were antigenically similar to the virus component in the quadrivalent vaccine for 2018/2019. Conclusions: A simultaneous circulation of genetically and antigenically diverse A(H3N2) and B/Victoria viruses was observed and represented a challenge to vaccine strain selection.