Complex sentence: This was a significant change in the relationship between the British state and its citizens, and there was a backlash, initially focused against compulsion, and later including arguments that vaccination was dangerous and ineffective.
Split into simpler sentences: This was a significant change in the relationship between the British state and its citizens, and there was a public backlash. Initially this was focused against compulsory vaccination, and later included arguments that vaccination was dangerous and ineffective.