Contemporary H3N2 influenza viruses have a glycosylation site that alters binding of antibodies elicited by egg-adapted vaccine strains

H3N2 viruses continuously acquire mutations in the hemagglutinin (HA) glycoprotein that abrogate binding of human antibodies. During the 2014–2015 influenza season, clade 3C.2a H3N2 viruses possessing a new predicted glycosylation site in antigenic site B of HA emerged, and these viruses remain prevalent today. The 2016–2017 seasonal influenza vaccine was updated to include a clade 3C.2a H3N2 strain; however, the egg-adapted version of this viral strain lacks the new putative glycosylation site. Here, we biochemically demonstrate that the HA antigenic site B of circulating clade 3C.2a viruses is glycosylated. We show that antibodies elicited in ferrets and humans exposed to the egg-adapted 2016–2017 H3N2 vaccine strain poorly neutralize a glycosylated clade 3C.2a H3N2 virus. Importantly, antibodies elicited in ferrets infected with the current circulating H3N2 viral strain (that possesses the glycosylation site) and humans vaccinated with baculovirus-expressed H3 antigens (that possess the glycosylation site motif) were able to efficiently recognize a glycosylated clade 3C.2a H3N2 virus. We propose that differences in glycosylation between H3N2 egg-adapted vaccines and circulating strains likely contributed to reduced vaccine effectiveness during the 2016–2017 influenza season. Furthermore, our data suggest that influenza virus antigens prepared via systems not reliant on egg adaptations are more likely to elicit protective antibody responses that are not affected by glycosylation of antigenic site B of H3N2 HA.

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H3N2 Virus as Causative Agent of ARDS Requiring Extracorporeal Membrane Oxygenation Support

Case Reports in Medicine ◽

10.1155/2014/560208 ◽

2014 ◽

Vol 2014 ◽

pp. 1-3

Author(s):

Adriano Peris ◽

Giovanni Zagli ◽

Pasquale Bernardo ◽

Massimo Bonacchi ◽

Morena Cozzolino ◽

...

Keyword(s):

Intensive Care Unit ◽

Extracorporeal Membrane Oxygenation ◽

Influenza A ◽

Seasonal Influenza ◽

Influenza Season ◽

Influenza Viruses ◽

H3n2 Virus ◽

Membrane Oxygenation ◽

Viral Aetiology ◽

Increased Risk

Pandemic influenza virus A(H1N1) 2009 was associated with a higher risk of viral pneumonia in comparison with seasonal influenza viruses. The influenza season 2011-2012 was characterized by the prevalent circulation of influenza A(H3N2) viruses. Whereas most H3N2 patients experienced mild, self-limited influenza-like illness, some patients were at increased risk for influenza complications because of age or underlying medical conditions. Cases presented were patients admitted to the Intensive Care Unit (ICU) of ECMO referral center (Careggi Teaching Hospital, Florence, Italy). Despite extracorporeal membrane oxygenation treatment (ECMO), one patient with H3N2-induced ARDS did not survive. Our experience suggests that viral aetiology is becoming more important and hospitals should be able to perform a fast differential diagnosis between bacterial and viral aetiology.

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2556. Retrospective Evaluation of Mismatch From Egg-Based Isolation of Influenza Strains Compared With Cell-Based Isolation and the Possible Implications for Vaccine Effectiveness

Open Forum Infectious Diseases ◽

10.1093/ofid/ofy209.164 ◽

2018 ◽

Vol 5 (suppl_1) ◽

pp. S69-S69 ◽

Cited By ~ 3

Author(s):

S Rajaram ◽

Josephine Van Boxmeer ◽

Brett Leav ◽

Pirada Suphaphiphat ◽

Ike Iheanacho ◽

...

Keyword(s):

Mdck Cells ◽

Glycosylation Site ◽

Vaccine Effectiveness ◽

Influenza Viruses ◽

H3n2 Virus ◽

Wild Type Virus ◽

Wild Type ◽

Research Support ◽

Antigenic Similarity ◽

H3n2 Vaccine

Abstract Background Lower influenza vaccine effectiveness (VE) against circulating H3N2 strains compared with other influenza viruses is partly explained by antigenic mismatch between circulating strains and the vaccine strain (Belongia 2016). This mismatch has recently been linked to a new glycosylation site introduced in the egg-adaptation step (Zost 2017) and HA L194P substitution (Wu 2017) for H3N2. Vaccine manufactured using seed virus wholly grown in mammalian (e.g., Madin–Darby Canine Kidney—MDCK) cells, as with the NH17-18 version of Flucelvax®, avoids these mutations. Preliminary reports suggest that this cell-based vaccine showed greater VE than did similar egg-based vaccines [FDA Statement]. This study aimed to compile existing data on antigenic similarity to measure the degree of match with circulating wild-type isolates of egg- and MDCK-propagated versions of the vaccine H3N2 virus over multiple seasons. Methods Using publicly available reports from the Worldwide Influenza Centre, London (Crick), we compiled data on antigenic similarity, defined as H3N2 circulating wild-type virus isolates showing no more than a 4-fold reduction in titer to antisera raised against wholly MDCK- or egg-propagated versions of the vaccine H3N2 viruses. Titers were compared using hemagglutination inhibition (HI) assays and/or plaque reduction neutralization assays (PRNA). Results Data from Northern Hemisphere influenza seasons of 2011–2012 to 2017–2018 show a substantially higher proportion of tested circulating influenza H3N2 viruses matched the MDCK-propagated reference viruses than did corresponding egg-propagated reference vaccine viruses (Figures 1 and 2). In half of the seasons evaluated, there was little to no antigenic similarity between circulating viruses and the egg-based vaccine viral seed. Conclusion These data suggest higher levels of mismatch have occurred consistently with egg-propagated H3N2 reference viruses compared with MDCK-propagated reference viruses when measured against circulating wild-type isolates and may further explain the potential for lower VE observed against H3N2 historically. Furthermore, these data point to the importance of continuing to utilize cell-derived seeds in creating seasonal influenza vaccines for this strain. Disclosures S. Rajaram, Seqirus: Employee, Salary. J. Van Boxmeer, Seqirus: Employee, Salary. B. Leav, Seqirus: Employee and Shareholder, Salary. P. Suphaphiphat, Seqirus: Employee, Salary. I. Iheanacho, Seqirus: Consultant, Research support. K. Kistler, Seqirus: Consultant, Research support.

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Antigenic and virological properties of an H3N2 variant that will likely dominate the 2021-2022 Northern Hemisphere influenza season

10.1101/2021.12.15.21267857 ◽

2021 ◽

Author(s):

Marcus J. Bolton ◽

Jordan T. Ort ◽

Ryan McBride ◽

Nicholas J. Swanson ◽

Jo Wilson ◽

...

Keyword(s):

Influenza Virus ◽

Northern Hemisphere ◽

Influenza Season ◽

Glycosylation Site ◽

Influenza Viruses ◽

Glycan Array ◽

Population Immunity ◽

Sialic Acid Binding ◽

Low Levels ◽

H3n2 Vaccine

Influenza viruses have circulated at very low levels during the COVID-19 pandemic, and population immunity against these viruses is low. Influenza virus cases have been increasing in the Northern Hemisphere involving an H3N2 strain (3C.2a1b.2a2) with a hemagglutinin (HA) that has several substitutions relative to the 2021-2022 H3N2 vaccine strain. Here, we show that one of these substitutions eliminates a key glycosylation site on HA and alters sialic acid binding. Using glycan array profiling, we show that the 3C.2a1b.2a2 H3 maintains binding to an extended bi-antennary sialoside and replicates to high titers in human airway cells. We found that antibodies elicited by the 2021-2022 Northern Hemisphere influenza vaccine poorly neutralize the new H3N2 strain. Together, these data indicate that 3C.2a1b.2a2 H3N2 viruses efficiently replicate in human cells and could potentially cause an antigenic mismatch if they continue to circulate at high levels during the 2021-2022 influenza season.

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Next generation methodology for updating HA vaccines against emerging human seasonal influenza A(H3N2) viruses

Scientific Reports ◽

10.1038/s41598-020-79590-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

James D. Allen ◽

Ted M. Ross

Keyword(s):

Influenza Virus ◽

Immune Responses ◽

Influenza A ◽

Seasonal Influenza ◽

Influenza Viruses ◽

Next Generation ◽

Virus Infections ◽

Wild Type ◽

Influenza Hemagglutinin ◽

H3n2 Influenza

AbstractWhile vaccines remain the best tool for preventing influenza virus infections, they have demonstrated low to moderate effectiveness in recent years. Seasonal influenza vaccines typically consist of wild-type influenza A and B viruses that are limited in their ability to elicit protective immune responses against co-circulating influenza virus variant strains. Improved influenza virus vaccines need to elicit protective immune responses against multiple influenza virus drift variants within each season. Broadly reactive vaccine candidates potentially provide a solution to this problem, but their efficacy may begin to wane as influenza viruses naturally mutate through processes that mediates drift. Thus, it is necessary to develop a method that commercial vaccine manufacturers can use to update broadly reactive vaccine antigens to better protect against future and currently circulating viral variants. Building upon the COBRA technology, nine next-generation H3N2 influenza hemagglutinin (HA) vaccines were designed using a next generation algorithm and design methodology. These next-generation broadly reactive COBRA H3 HA vaccines were superior to wild-type HA vaccines at eliciting antibodies with high HAI activity against a panel of historical and co-circulating H3N2 influenza viruses isolated over the last 15 years, as well as the ability to neutralize future emerging H3N2 isolates.

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Longitudinal sampling is required to maximize detection of intrahost A/H3N2 virus variants

Virus Evolution ◽

10.1093/ve/veaa088 ◽

2020 ◽

Vol 6 (2) ◽

Author(s):

B F Koel ◽

R M Vigeveno ◽

M Pater ◽

S M Koekkoek ◽

A X Han ◽

...

Keyword(s):

Neutralizing Antibodies ◽

De Novo ◽

Diagnostic Testing ◽

Influenza Viruses ◽

Surface Proteins ◽

H3n2 Virus ◽

Virus Population ◽

Sample Collection ◽

Routine Surveillance ◽

H3n2 Influenza

Abstract Seasonal human influenza viruses continually change antigenically to escape from neutralizing antibodies. It remains unclear how genetic variation in the intrahost virus population and selection at the level of individual hosts translates to the fast-paced evolution observed at the global level because emerging intrahost antigenic variants are rarely detected. We tracked intrahost variants in the hemagglutinin and neuraminidase surface proteins using longitudinally collected samples from 52 patients infected by A/H3N2 influenza virus, mostly young children, who received oseltamivir treatment. We identified emerging putative antigenic variants and oseltamivir-resistant variants, most of which remained detectable in samples collected at subsequent days, and identified variants that emerged intrahost immediately prior to increases in global rates. In contrast to most putative antigenic variants, oseltamivir-resistant variants rapidly increased to high frequencies in the virus population. Importantly, the majority of putative antigenic variants and oseltamivir-resistant variants were first detectable four or more days after onset of symptoms or start of treatment, respectively. Our observations demonstrate that de novo variants emerge, and may be positively selected, during the course of infection. Additionally, based on the 4–7 days post-treatment delay in emergence of oseltamivir-resistant variants in six out of the eight individuals with such variants, we find that limiting sample collection for routine surveillance and diagnostic testing to early timepoints after onset of symptoms can potentially preclude detection of emerging, positively selected variants.

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Detection of adamantane-sensitive influenza A(H3N2) viruses in Australia, 2017: a cause for hope?

Eurosurveillance ◽

10.2807/1560-7917.es.2017.22.47.17-00731 ◽

2017 ◽

Vol 22 (47) ◽

Cited By ~ 4

Author(s):

Aeron Hurt ◽

Naomi Komadina ◽

Yi-Mo Deng ◽

Matthew Kaye ◽

Sheena Sullivan ◽

...

Keyword(s):

Influenza A ◽

Influenza Season ◽

Influenza Viruses ◽

M2 Protein ◽

H3n2 Influenza

For over a decade virtually all A(H3N2) influenza viruses have been resistant to the adamantane class of antivirals. However, during the 2017 influenza season in Australia, 15/461 (3.3%) adamantane-sensitive A(H3N2) viruses encoding serine at residue 31 of the M2 protein were detected, more than the total number identified globally during the last 6 years. A return to wide circulation of adamantane-sensitive A(H3N2) viruses would revive the option of using these drugs for treatment and prophylaxis.

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Immunodominance of Antigenic Site B over Site A of Hemagglutinin of Recent H3N2 Influenza Viruses

PLoS ONE ◽

10.1371/journal.pone.0041895 ◽

2012 ◽

Vol 7 (7) ◽

pp. e41895 ◽

Cited By ~ 66

Author(s):

Lyubov Popova ◽

Kenneth Smith ◽

Ann H. West ◽

Patrick C. Wilson ◽

Judith A. James ◽

...

Keyword(s):

Antigenic Site ◽

Influenza Viruses ◽

H3n2 Influenza

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Antigenic and genetic analysis of equine influenza viruses from tropical Africa in 1991

Epidemiology and Infection ◽

10.1017/s0950268800001552 ◽

1996 ◽

Vol 117 (2) ◽

pp. 367-374 ◽

Cited By ~ 4

Author(s):

C. A. O. Adeyefa ◽

M. L. James ◽

J. W. McCauley

Keyword(s):

Amino Acid ◽

Nucleotide Sequence ◽

Antigenic Site ◽

Glycosylation Site ◽

Influenza Viruses ◽

Amino Acid Substitutions ◽

Antigenic Analysis ◽

Equine Influenza ◽

Antigenic Sites ◽

European Strain

SummaryA detailed analysis of equine (H3N8) influenza viruses isolated in Nigeria during early 1991 has been undertaken. Antigenic analysis and the complete nucleotide sequence of the HA gene of three Nigerian equine influenza viruses A/eq/Ibadan/4/91, A/eq/Ibadan/6/91 and A/eq/Ibadan/9/91 are presented and limited sequence analysis of each of the genes encoding the internal polypeptides of the virus has been carried out. These results establish that, despite the geographical location from which these viruses were isolated, two were similar to the viruses which were concurrently causing disease in Europe in 1989 and 1991 and were related to viruses that have been predominating in horses since 1985. The third was more closely related to viruses isolated from 1991 onward in Europe but also in other parts of the globe. A comparison of the nucleotide sequence of two of the viruses isolated in Nigeria (A/eq/Ibadan/4/91 and A/eq/Ibadan/6/91) with a European strain (A/eq/Suffolk/89) showed limited variation in the haemagglutinin gene which caused amino acid substitutions in one of the antigenic sites: this mutation resulted in the potential production of a new glycosylation site in antigenic site A. The other Nigerian virus (A/eq/Ibadan/9/91) showed only a single one amino acid change from another European strain (A/eq/Arundel/12369/91). The two distinct Nigerian viruses had several amino acid substitutions in the antigenic sites of the haemagglutinin glycoprotein.

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Surveillance of influenza viruses isolated from travellers at Nagoya International Airport

Epidemiology and Infection ◽

10.1017/s0950268899003738 ◽

2000 ◽

Vol 124 (3) ◽

pp. 507-514 ◽

Cited By ~ 12

Author(s):

K. SATO ◽

T. MORISHITA ◽

E. NOBUSAWA ◽

Y. SUZUKI ◽

Y. MIYAZAKI ◽

...

Keyword(s):

Influenza A ◽

Respiratory Symptoms ◽

H1n1 Virus ◽

Influenza Season ◽

Influenza Viruses ◽

H3n2 Virus ◽

Influenza B ◽

International Airport ◽

Quarantine Station ◽

Virus Strains

In order to conduct a survey of influenza viruses entering Japan via travellers arriving by airplanes, gargle solutions were collected from passengers who reported to the quarantine station of Nagoya International Airport complaining of respiratory symptoms. From 504 samples collected between August 1996 and March 1999, 30 influenza virus strains were isolated. Twenty-eight of the isolates were influenza A (H3N2) viruses and two were influenza B viruses. No H1N1 virus was isolated. Among 28 isolates of H3N2 virus, 3 strains were obtained outside the influenza season. Nucleotide sequences of the haemagglutinin (HA) genes of these isolates along with those from domestic patients were analysed in order to determine the influence of imported influenza viruses by travellers on epidemics in Japan. From the phylogenetic and chronological aspects, the possibility was suggested in one case in 1997/8 and two in the 1998/9 season that imported virus by travellers may have influenced the domestic influenza epidemics.

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What will the next influenza season bring about: seasonal influenza or the new A(H1N1)v? An analysis of German influenza surveillance data

Eurosurveillance ◽

10.2807/ese.14.32.19303-en ◽

2009 ◽

Vol 14 (32) ◽

Author(s):

H Uphoff ◽

S Geis ◽

A Grüber ◽

A M Hauri

Keyword(s):

Influenza A ◽

Seasonal Influenza ◽

Influenza Season ◽

Influenza Viruses ◽

Moderate Intensity ◽

Influenza Surveillance ◽

Influenza B ◽

Low Intensity ◽

Influenza A H1n1 ◽

Using Data

For the next influenza season (winter 2009-10) the relative contributions to virus circulation and influenza-associated morbidity of the seasonal influenza viruses A(H3N2), A(H1N1) and B, and the new influenza A(H1N1)v are still unknown. We estimated the chances of seasonal influenza to circulate during the upcoming season using data of the German influenza sentinel scheme from 1992 to 2009. We calculated type and subtype-specific indices for past exposure and the corresponding morbidity indices for each season. For the upcoming season 2009-10 our model suggests that it is unlikely that influenza A(H3N2) will circulate with more than a low intensity, seasonal A(H1N1) with more than a low to moderate intensity, and influenza B with more than a low to median intensity. The probability of a competitive circulation of seasonal influenza A with the new A(H1N1)v is low, increasing the chance for the latter to dominate the next influenza season in Germany.

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