The Resurgent Threat of Highly Pathogenic Avian Influenza HPAI A (H5N1) Virus: A Zoonotic Infectious Disease and Public Health Concern

The highly pathogenic avian influenza (HPAI) A (H5N1) virus of clade 2.3.4.4b was identified among waterfowl (wild birds and geese) and domestic poultry across Southeast Asia, Europe, and Africa in 2021. By 2022, the HPAI virus was detected in North America, signifying further global dissemination. There is no human immunity to clade 2.3.4.4b A (H5N1). With the spread of the A (H5N1) virus throughout the United States and increasing viral infection in humans, resurgence of the A (H5N1) virus is of great public health concern that it could lead to the next infectious zoonotic pandemic after Covid-19. This paper describes the characteristics of HPAI A (H5N1) virus of clade 2.3.4.4b and recommendations for clinical treatment and prevention.