24 out of 10,000 tests, where the whole population in that 'area' is tested, is equivalent to 240 per 100,000 head of population which warrants tier 4.
For comparison, Swale which is about 20 miles from Manston airport, was approaching 900 per 100,000 when we were placed into tier 4. Suffice to say, 100,000 tests were not carried out in the borough and those are estimated figures of the incidence.
Other areas such as on the Essex-Greater London border now exceed that figure.
Vaccination minimises the affect of the disease if you catch it, an effective test and trace system identifies who has it and allows you to take steps to limit the spread. I don't believe we have the latter as a world-beating system.