Countries essentially have a 'transmission budget' when it comes to COVID-19 - current global patterns suggest there are only so many things that can go back to normal before flare-ups start happening... 1/
Infection control, test + trace etc. can increase the available budget, and traveller quarantines can reduce imported cases (& hence potential for new transmission chains). Even so, several places are now reintroducing measures after new outbreaks following initial reopening. 2/
With winter approaching in Europe, and schools still yet to reopen in some places, finding an effective, sustainable balance of measures will be crucial if countries want to avoid damaging second waves. 3/
Good local-level situational awareness will be particularly important here. How many new cases are already in quarantine? How are new clusters of cases happening and how are they linked? How can we be confident there aren't asymptomatic infections in high-risk environments? 4/4
