Maybe they have a little less flu but I’d much rather have the flu then increase birth defects, miscarriages, and a host of other problems that come with vaccinating. Since the study only measures the flu we don’t know what other kinds of health problems these vaccinated mothers experienced. There’s no such thing as a drug without side effects.
I’d be willing to be mothers who ate a very healthy diet, weren’t over stress, and got sunlight and fresh air had the lowest rate of flu of anyone.