This information comes from medical specialists:
In general, based on current understanding of BWS, there does not seem to be a specific effect on the immune system placing children with BWS at increased risk for serious infection by COVID-19. However, children with BWS and the following rare conditions are possibly at an increased risk of serious infection from a viral illness:
1. Chronic lung disease due to prematurity
2. Airway obstruction due to severe macroglossia
3. A cancer diagnosis and currently undergoing chemotherapy
4. On immunosuppressant therapy (e.g. for liver transplantation)
There may be other circumstances that may occasionally pose a risk and any concerns should be discussed with your doctor.