But, fortunately, it cannot continue indefinitely
The health secretary impressed parliament last week when he said daily Omicron infections were estimated at about 200,000. This was classic “number theatre” – pulling a big statistic out of a hat without supporting evidence. Although the Health Security Agency (UKHSA) later briefed the press, it only publicly revealed its workings on Thursday: it had estimated 23,000 Omicron infections on 7 December, then assumed exponential growth with a doubling time of 1.9 days. We will have to wait for infection survey estimates to know if this is accurate.
Exponential growth simply means something increases in proportion to its current value – the bigger it gets, the more it increases each day. This does not necessarily mean “fast” – a savings account has this kind of growth, even with a 0.1% compound interest rate.