“全球55国抗击疫情”可译为55 countries worldwide fighting the COVID-19 pandemic或55 nations across the globe combating the epidemic。常用表达包括：
- fight/combat the pandemic：抗击疫情
- global efforts against COVID-19：全球抗疫努力
- 55 countries have joined the battle against the virus：55国加入抗疫战斗
注意：pandemic指全球大流行，epidemic指地区性流行病。例句：Fifty-five countries worldwide are working together to fight the pandemic.