Because their system is so poor that unable them to past through a health crisis like that.
Explanation:
The main reason is because developing countries lack of efficiency in so many areas. The major part of their population don't have fair access to healthcare, education, decent jobs and they lack of goods to support their people. On the other hand, their science is not develop enough to innovate and offer to their society solutions to emergency problems.
Developing countries might be more vulnerable to modern pandemics because they are poor and underdeveloped, this can lead to: 1) fewer supplies of medicines and vaccines 2) poor healthcare system 3) underdeveloped hospitals 4) Inadequate scientific programs to research the pandemics 5) poor living conditions helps spread disease quicker 6) A less educated population could be underinformed about the pandemic
