Answer:
Due to no controlling agent for harmful microbes that causes new pandemic.
Explanation:
The new pandemic leads to imbalance of ecosystem due to biodiversity loss because the absence of antimicrobial agent causes the pandemic. The antimicrobial agent is responsible for the control of harmful microorganism so due to disturbance in the ecosystem, the biodiversity losses occurs and there is no organism which stop or control the population of the harmful organism that causes new pandemic.