Festinger identified five conditions that needed to be met in order for the cult members to double down on their beliefs and avoid cognitive dissonance.
1. There must be conviction
2. There must be commitment to this conviction
3. The conviction must be amenable to unequivocal disconfirmation
4. Such unequivocal disconfirmation must occur
5. Social support must be available subsequent to the disconfirmation.
https://www.zerohedge.com/health/psychotherapist-lockdown-zealots-are-behaving-cult-members