Scientists have predicted the best strategy for lifting the COVID-19 lockdowns across Europe.
Currently, many countries across the continent are lifting and relaxing COVID-19 lockdowns, but how the lockdowns will be completely lifted remains to be seen. The scientists from the University of Oxford and the UK Centre for Ecology and Hydrology in Wallingford suggest that a gradual strategy with two steps which are releases of subgroups of the quarantined population would be the optimal method for releasing lockdown in order to minimise deaths and protect the economy.
The study has been published in Frontiers in Public Health.
A two-step approach to lifting lockdowns
The scientists used mathematical modelling to make the prediction for what might be the best method for society to begin returning to normal – modelling the numbers of susceptible, exposed, infectious, and recovered (or deceased) persons in the UK, separately for those under lockdown and those working as normal.
The researchers concluded that the optimal strategy would be a two-step approach to lifting lockdown by releasing half of the population two to four weeks from the end of the initial infection peak. They suggest to then wait another three or four months to allow for a potential second peak to pass before releasing everyone else. The method, however, does not state which people should be released from lockdown first, although the authors suggest it should be the younger half.
The authors wrote: ‘We find that ending quarantine for the entire population simultaneously is a high-risk strategy and that a gradual re-integration approach would be more reliable’.
Act with caution
Lead author, Professor Michael Bonsall from the Mathematical Ecology Research Group at the University of Oxford, said: “Exactly what happens as lockdown eases can be hard to predict, as different people will respond in different ways. However, when a large enough group of people is considered, mathematical models like ours are able to represent the expected average behaviours across a large population. Most importantly, we are able to assume a wide range of “What if?” scenarios, such that we can explore a range of possible infection increases. Ongoing testing is then important to check that any disease increase does not surpass the predicted bounds.”
“The take-home message for decision-makers is to act very cautiously and to monitor any lockdown release very closely. Our model shows that second waves can occur very quickly if transmission rates end up higher than expected, or if more people relax their lockdown measures than expected. The delayed incubation period between infection and presenting symptoms means that we are constantly seeing the effect of the disease a few days late.
“Only by ramping up testing measures can we accurately get a sense of how the spread and control of disease is happening. This will allow us to respond quickly if an unmanageable second wave begins to appear,” added first author Dr Thomas Rawson from the University of Oxford.