infrequent
When I was a lad, travelling to anywhere from the UK required valid certificates of vaccination (though we might have called it inoculation back then) against smallpox, cholera, typhoid, and paratyphoid A and B (seems to stay with me like a litany; cholera didn't really do much good, but this was before there was the modern treatment). When I first went to live in Australia, regular chest x-rays were legally required, because of the hangover of TB. The economic impact of Covid-19 is great, and falls very unevenly without any suggestion of fairness; but people in the first and second worlds have got used to not having to comply with any public health measures and expect infectious disease to have no impact on daily life, and I will sign off before I start sounding like four Yorkshiremen talking about the masks they had to wear underneath their masks.