Vaccines (Basel). 2018 Nov 1;6(4). pii: E74. doi: 10.3390/vaccines6040074.
Two Live Attenuated Vaccines against Recent Low⁻and Highly Pathogenic H7N9 Influenza Viruses Are Safe and Immunogenic in Ferrets.

Rudenko L1, Kiseleva I2, Krutikova E3, Stepanova E4, Isakova-Sivak I5, Donina S6, Rekstin A7, Pisareva M8, Bazhenova E9, Kotomina T10, Katelnikova A11, Muzhikyan A12, Makarov V13, Sparrow EG14, Torelli G15.
Author information


Influenza H7N9 virus is a potentially pandemic subtype to which most people are immunologically na´ve. To be better prepared for the potential occurrence of an H7N9 pandemic, in 2017 the World Health Organization recommended developing candidate vaccine viruses from two new H7N9 viruses, A/Guangdong/17SF003/2016 (A/GD) and A/Hong Kong/125/2017 (A/HK). This report describes the development of live attenuated influenza vaccine (LAIV) candidates against A/GD and A/HK viruses and study of their safety and immunogenicity in the ferret model in order to choose the most promising one for a phase I clinical trial. The A/HK-based vaccine candidate (A/17/HK) was developed by classical reassortment in eggs. The A/GD-based vaccine candidate (A/17/GD) was generated by reverse genetics. Ferrets were vaccinated with two doses of LAIV or phosphate-buffered saline. Both H7N9 LAIVs tested were safe for ferrets, as shown by absence of clinical signs, and by virological and histological data; they were immunogenic after a single vaccination. These results provide a compelling argument for further testing of these vaccines in volunteers. Since the A/HK virus represents the cluster that has caused the majority of human cases, and because the A/HK-based LAIV candidate was developed by classical reassortment, this is the preferred candidate for a phase I clinical trial.


H7N9; avian influenza; live attenuated influenza vaccine; pandemic threat

PMID: 30388790 DOI: 10.3390/vaccines6040074
Free full text