As the UK waits out its third national lockdown, Christina Pagel lays out the steps needed for a country to exit the cycle

On 4 January, just as the rollout of new vaccines seemed to offer hope on the horizon, England entered its third national lockdown, following the likes of France, Germany, and Spain back into a familiar cycle of restrictions and perseverance.

Countries all over the world are grappling with the same dilemma. Until populations at large are vaccinated, people are not safe from covid-19, and though we know a lot more about the virus than a year ago, the many questions that remain mean the blunt tool of lockdowns and other social restrictions are the main weapon used, in Europe at least, against a virus that has infected over 100 million people and claimed over two million lives so far.

As millions are vaccinated across the UK, at what point is it safe to lift restrictions?

The dangers to consider

The dominance of new, more transmissible variants means that a policy of trying to “live with” the virus will fail, certainly in the UK where the new B.1.1.7 variant is now the most common. I know of no country that is successfully living with the virus while avoiding lockdown and restriction cycles, a high death toll, or—as in the UK—both.

We need to set our sights instead on where we want to be and then work out how to get there. The role models we have are Vietnam (35 deaths, 98 million population), Thailand (73 deaths, 70 million population), South Korea (1371 deaths, 51 million population), and New Zealand (25 deaths, 5 million population) where people have been living much more normal lives for months.

Following their example, the way out is for the UK to pursue a national suppression strategy—zero tolerance for any community transmission—which comes with the added benefit of protecting ourselves from homegrown vaccine resistant variants.

Vaccines will certainly help us to get there, but alone they will not suffice. We don’t yet know to what extent vaccines prevent transmission of the virus, but even if they were as effective at preventing transmission as they are at preventing symptomatic illness, we cannot vaccinate our way to no cases.

Herd immunity will not prevent local outbreaks in communities with lower uptake for years to come. And in the face of more transmissible strains, herd immunity would likely require at least 80% of the population to be protected from infection. Even with a very optimistic real world efficacy (as opposed to trial efficacy) of 90%, that would require vaccinating over 90% of people. In the face of vaccine hesitancy, particularly among minority groups; less interest in vaccination among the young; and no current licensed vaccine for children, we will not reach that threshold.

So, what should the UK do?

There are four steps to get to a new normal.

Firstly, we need to continue to vaccinate the entire adult population as quickly as possible to prevent long covid, severe illness, hospitalisations, and deaths. It is likely that this will also greatly reduce transmission, although we do not yet know by how much.

Secondly, we need to have strong restrictions in place until we have driven cases back down to levels last seen in the summer. Enhancing restrictions with a concerted effort to make workplaces safer and supporting self-isolation will greatly reduce the length of time needed.

Thirdly, we need to rebuild local contact tracing capability to aggressively drive cases down further as restrictions are eased and to spot and stamp down on new outbreaks in the months and years to come. This includes easily accessible tests, testing of all close contacts, and financial and practical support to isolate for those who test positive and their contacts. Investment in quicker, easier tests (such as saliva tests, provided accuracy was reasonable) would be enormously useful in supporting this effort, as would other tools such as monitoring waste water for traces of the virus.

Fourthly, we need strong border control with negative tests before and after travel and 14 day managed isolation on entry for everyone (including returning citizens). As we reach zero community transmission, any new community transmission that cannot be traced must be contained with local, short term, tight restrictions, as in Australia. On the other hand, travel corridors with other zero internal transmission countries could be explored.

I don’t know, however, if any single country can realistically exit the pandemic unless all countries do. Without global suppression, a vaccine resistant strain is likely to emerge and covid will spread again. That’s why the ultimate solution is for the UK to work internationally to ensure rapid vaccination and a robust strategy for monitoring transmission, identifying new variants, and coordinated border control.

Christina Pagel, director, Clinical Operational Research Unit, University College London, UK.

Competing interests: None declared.