Chinese health experts called on Norway and other countries to suspend the use of mRNA-based COVID-19 vaccines produced by companies such as Pfizer, especially among elderly people, due to the vaccines' safety uncertainties following the deaths of 23 elderly Norwegian people who received the vaccine. 

The new mRNA vaccine was developed in haste and had never been used on a large scale for the prevention of infectious disease, and its safety had not been confirmed for large-scale use in humans, a Chinese immunologist said.