Its widely believed thatnowaday, using vaccines can prevent getting affected from lots of viruses
.... Should be either ; It is / It's, nowadays
Also, why only nowadays? Even in the past, people used vaccines as a disease prevention method.
I think that without vaccines the diseases could return and spread out easily from one person to another
However, I think it is necessary to force people to get themselves immunized, especially the young children, in order to prevent them from childhood diseases.I think you need to pay attention to the essay format.