This is the place where the story must be told as simply and clearly as possible, and I think a lot of the abstract is confusing and hard to interpret.
Finally, and this is my biggest remaining concern, the authors have not responded to my comment regarding the lack of explanations on how the flexible adding and removal of the proposed services would be achieved. This is still unclear to me in the paper. This is a very important point, since it changes what is the contribution of the paper. The current contribution seems to be the proposal of new services to handle the COVID situation, or similar situations in the future. However, I am lacking the contribution on the more general issue of integrating and removing services in an existing smart city infrastructure. In other terms, what can we use from the authors' paper to achieve a more flexible smart city service structure?