1. I.I. Mechnikov Institute of Vaccines and Sera, 105064 Moscow, Russia
2. G.P. Somov Institute of Epidemiology and Microbiology, Rospotrebnadzor, 690087 Vladivostok, Russia
3. G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 690022 Vladivostok, Russia
4. Central Research Institute of Epidemiology, Rospotrebnadzor, 111123 Moscow, Russia