Alveolar macrophages (AMs) are lung-resident myeloid cells that sit at the interface of the airway and lung tissue. Under homeostatic conditions, their primary function is to clear debris, dead cells and excess surfactant from the airways. They also serve as innate pulmonary sentinels for respiratory pathogens and environmental airborne particles and as regulators of pulmonary inflammation. However, they have not typically been viewed as primary therapeutic targets for respiratory diseases. Here, we discuss the role of AMs in various lung diseases, explore the potential therapeutic strategies to target these innate cells and weigh the potential risks and challenges of such therapies. Additionally, in the context of the COVID-19 pandemic, we examine the role AMs play in severe disease and the therapeutic strategies that have been harnessed to modulate their function and protect against severe lung damage. There are many novel approaches in development to target AMs, such as inhaled antibiotics, liposomal and microparticle delivery systems, and host-directed therapies, which have the potential to provide critical treatment to patients suffering from severe respiratory diseases, yet there is still much work to be done to fully understand the possible benefits and risks of such approaches.

Low pathogenic avian influenza virus (LPAI) subtype H9N2 in poultry has occurred in many countries since the mid-1990s. Outbreaks due to H9N2 have occurred in Korea, Germany, Italy, Ireland, South Africa and the USA. Most recently, H9N2 infections have been reported in several Asian countries, the Middle East and Africa, causing widespread outbreaks in commercial chickens. In these countries, vaccine has been distributed with the aim of controlling the disease. However, H9N2 infections have become endemic in commercial poultry in a significant number of countries. This review is aimed to shed light on the current situation of the LPAI world-wide.

This Panel Session consisted of three country reports (Democratic People's Republic of Korea; Sri Lanka; and Timor-Leste) and the common issues identified during the Panel discussions relative to industrial accidents and conflicts in the Southeast Asia Region. Important issues identified included the needs for: (1) use of medical technology; (2) stockpiling of essential supplies; (3) human resource development; (4) surveillance systems for disease detection; (5) coordination; and (6) emergency funding.