Influenza B [B/Washington/02/2019 (B/Victoria lineage)-like virus] Hemagglutinin (HA), His-Tag

INFLUENZA B [B/WASHINGTON/02/2019 (B/VICTORIA LINEAGE)-LIKE VIRUS] HEMAGGLUTININ (HA), HIS-TAG

This Influenza virus hemagglutinin protein is derived from the HA sequence of the B/Washington/02/2019 (B/Victoria lineage)-like virus, expressing aa 31-469, and fused with a polyhistidine tag at the C-terminus. The influenza virus hemagglutinin protein is expressed in HEK293 cells. This virus is recommended by WHO for inclusion in the quadrivalent vaccines for use in the 2021 – 2022 northern hemisphere influenza season.

PRODUCT DETAILS – INFLUENZA B [B/WASHINGTON/02/2019 (B/VICTORIA LINEAGE)-LIKE VIRUS] HEMAGGLUTININ (HA), HIS-TAG

• Recombinant Influenza B [B/Washington/02/2019 (B/Victoria lineage)-like virus] (NCBI Accession Number: EPI1846769), amino acids 31-469 and a C-terminal His-tag.
• Expressed in HEK293 cells, and purified from culture supernatant by immobilized metal affinity chromatography and buffer exchange.
• Presented as liquid in DPBS and greater than >95% purity by SDS-PAGE.

BACKGROUND

Influenza B virus is the only species in the genus Betainfluenzavirus in the virus family Orthomyxoviridae. Influenza B virus is only known to infect humans and seals and this is believed to account for the lack of associated influenza pandemics in contrast with those caused by the morphologically similar influenza A virus, although both mutate by both antigenic drift and reassortment. However, it is thought that Influenza B virus could cause significant morbidity and mortality worldwide, particularly in adolescents and schoolchildren. WHO convenes technical consultations in February and September each year to recommend viruses for inclusion in influenza vaccines for the northern and southern hemisphere influenza seasons, respectively. Flu vaccines are based on predicting which mutants of H1N1, H3N2, H1N2, and influenza B will proliferate in the next season. Separate vaccines are developed for the Northern and Southern Hemispheres in preparation for their annual epidemics. One influenza A (H1N1), one influenza A (H3N2), and one or two influenza B viruses (depending on the vaccine) are included in each season’s influenza vaccines (CDC, 2019). WHO has identified four strains as the most likely to circulate in the 2020-2021 influenza season, including Influenza B [B/Washington/02/2019] virus.

Globally, more influenza B viruses were detected than influenza A viruses during this period and influenza B viruses have predominated since November 2020. Of the influenza B viruses where lineage was determined, nearly all were the B/Victoria/2/87 lineage and the majority were reported from Afghanistan, China, Côte d’Ivoire, Ghana, Guinea, Haiti and Senegal. B/Yamagata/16/88 lineage viruses were reported in very low numbers by a few countries (Afghanistan, Sweden and the United States of America). WHO recommends that trivalent and quadrivalent vaccines for use in the 2021-2022 northern hemisphere influenza season contain Influenza B [B/Washington/02/2019 (B/Victoria lineage)-like virus] (WHO, 2021).

Since December, 2019, coronavirus disease 2019 (COVID-19) has been an international public health emergency and co-infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory viruses have been reported, complicating their diagnosis (Azekawa et al., 2020; Cuadrado-Payán et al., 2020; Wu et al., 2020).

REFERENCES

• • Azekawa S, Namkoong H, Mitamura K, Kawaoka Y, Saito F. Co-infection with SARS-CoV-2 and influenza A virus. IDCases. 2020;20:e00775. Published 2020 Apr 21.
  • Centers for Disease Control and Prevention (CDC). (2019). Influenza (Flu).
  • Cuadrado-Payán E, Montagud-Marrahi E, Torres-Elorza M, et al. SARS-CoV-2 and influenza virus co-infection. Lancet. 2020;395(10236):e84.
  • WHO. Recommended composition of influenza virus vaccines for use in the 2021-2022 northern hemisphere influenza season. 2021.
  • Wu X, Cai Y, Huang X, et al. Co-infection with SARS-CoV-2 and Influenza A Virus in Patient with Pneumonia, China. Emerg Infect Dis. 2020;26(6):1324-1326.