M.K. ISKHAKOVA1, N.I. PENKINA1, M.A. IVANOVA2 1Izhevsk State Medical Academy, Izhevsk 2Russian Research Institute of Health, Moscow  Contact details: Penkina N.I. — MD, Professor, Professor of the Department of Pediatrics and Neonatology Address: 281 Kommunarov St., 426034 Izhevsk, Russian Federation, tel.: +7 (3412) 65-81-67, e-mail: nad.penkina@yandex.ru  In different age groups, the course of COVID-19 has varying degrees […]