Masks were once mandatory in public places but, as the rules have loosened, fewer people appear to choose to wear one, RNZ reports. People are still encouraged to wear a mask in crowded places, enclosed spaces with poor ventilation, close contact settings, or when visiting people at high risk. Epidemiological modeller James Trauer says wearing a mask was still considerably better than nothing. “However, it is likely that the greatest effect is when the infector [the person with Covid-19] is wearing one,” he said. “This is one of the strongest justifications for requiring everyone to wear a mask, particularly indoors.”