Archives of Virology
Humoral immunity to inuenza in an at‑risk population and severe
inuenza cases in Russia in 2016–2017
Tatyana N. Ilyicheva
· Alexander G. Durymanov
· Svetlana V. Svyatchenko
· Vasily Yu. Marchenko
Ivan A. Sobolev
· Anastasiya Yu. Bakulina
· Natalia I. Goncharova
· Natalia P. Kolosova
· Ivan M. Susloparov
Olga G. Pyankova
· Alexander B. Ryzhikov
· Rinat A. Maksyutov
Received: 3 March 2018 / Accepted: 19 April 2018
© Springer-Verlag GmbH Austria, part of Springer Nature 2018
This work aimed to analyze the herd immunity to inﬂuenza among a Russian population living in regions with an increased
risk of emergence of viruses with pandemic potential, and to isolate and investigate virus strains from severe inﬂuenza cases,
including fatal cases, during the 2016–2017 epidemic season. In November 2016 – March 2017 highly pathogenic inﬂuenza
outbreaks were registered in Russia among wild birds and poultry. No cases of human infection were registered. Analysis
of 760 sera from people who had contact with infected or perished birds revealed the presence of antibodies to A(H5N1)
virus of clade 126.96.36.199c and A(H5N8) virus of clade 188.8.131.52. The 2016–2017 inﬂuenza epidemic season in Russia began in
weeks 46–47 of 2016 with predominant circulation of inﬂuenza A(H3N2) viruses. Strains isolated from severe inﬂuenza
cases mainly belonged to 3C.2a.2 and 3C.2a.3 genetic groups. Up to the 8th week of 2017 severe inﬂuenza cases were often
caused by inﬂuenza B viruses which belonged to 1A genetic group with antigenic properties similar to B/Brisbane/60/2008.
All inﬂuenza A and B virus strains isolated in the 2016–2017 epidemic season were sensitive to oseltamivir and zanamivir.
Influenza is a human respiratory disease, which causes
annual inﬂuenza outbreaks, and in some cases pandemics.
Seasonal inﬂuenza epidemics often begin with increased
morbidity in children, achieve peak within 2–6 weeks and
last from 8 to 12 weeks. Usually inﬂuenza epidemics with a
predominant H3N2 subtype are accompanied by high mor-
bidity and mortality .
In Russia in 2016–2017 an increase in inﬂuenza mor-
bidity was registered in weeks 46–47 of 2016. At the start
of the epidemic, inﬂuenza A(H3N2) virus was mainly pre-
dominant, and the peak of morbidity was registered in the
2nd week of 2017. Later on (from the 3rd to 7th week of
2017) the number of infected people remained at its maxi-
mum level. In this period, the predominant inﬂuenza agent
changed: up to the 7th week of 2017 inﬂuenza A(H3N2)
had prevailed, after the 8th week inﬂuenza B virus was pre-
dominant . Generally, the main features of the 2016–2017
epidemic season included earlier and longer increases in
morbidity as compared to previous seasons, less intensity
in the epidemic process and lower fatality. About 55.9 mil-
lion people were vaccinated just before the epidemic season
resulting in an enhanced herd immunity to inﬂuenza in the
Russian population .
Since influenza viruses permanently circulate in the
wild, predominantly among wild birds, there is a continu-
ous possibility of the emergence of pandemic virus strains.
Inﬂuenza viruses have segmented genomes represented by
single-stranded RNA of negative polarity. When two virus
particles, which belong to diﬀerent inﬂuenza A subtypes,
enter one target cell, virus variants with unpredicted anti-
genic and virulent features can emerge due to reassortment.
Handling Editor: Ayato Takada.
Electronic supplementary material The online version of this
article (https ://doi.org/10.1007/s0070 5-018-3904-9) contains
supplementary material, which is available to authorized users.
* Tatyana N. Ilyicheva
Vector State Research Centre of Virology
and Biotechnology, Koltsovo, Novosibirsk Region 630559,
Novosibirsk State University, Novosibirsk 630090, Russia
Scientiﬁc Research Institute of Experimental and Clinical
Medicine, Novosibirsk 630060, Russia