COVID-19 pandemic by country and territory
But Professor Sir Ian Diamond warns people to remain "ever vigilant".
The president, who was not wearing a mask, claimed without evidence that 99% of US coronavirus cases are "totally harmless" at the event.
The warning from the BMA comes amid insight from scientists that there could be more local lockdowns in the UK.
The US, Brazil and UK have so far seen the highest number of Covid-19 victims.