Dr Raghib Ali is a Clinical Epidemiologist at the University of Cambridge and an Honorary Consultant in Acute Medicine at the Oxford University Hospitals NHS Trust.

When the Prime Minister unveiled the roadmap last month, I was relieved to see that he had not been swayed by those calling for a ‘Zero Covid’ strategy which was neither achievable nor desirable in the UK due to the huge costs it would entail.

The roadmap was broadly in line with what I had called for: a middle way between zero-covid and zero restrictions with a cautious, step-wise approach that was likely to minimise overall health harm and provided a clear path back to normality with no restrictions – and which could command wide scientific and public support. I was particularly pleased to see that priority given to children returning to schools and families being able to meet as the harms to education and health from these restrictions cannot be alleviated by government financial assistance.

I understand why some are frustrated by the slow pace of unlocking (particularly given the amazing success of the vaccine program) and as those who have followed my writings over the last year know, I am certainly no lockdown enthusiast.

The reason my views first attracted attention last Spring was because it was unusual for a frontline doctor to highlight the wider health harms of lockdown and to call for a comprehensive cost-benefit analysis to ensure that our response – and particularly school closures – was not causing more harm than benefit. And I argued against a second lockdown on the basis that it would only postpone and not prevent deaths; that compliance would be lower so reducing its effectiveness, and that it could cause more harm than benefit.

But I also accepted that Covid-19 had to be suppressed in order to prevent the NHS being overwhelmed and to reduce the health harms from fear. I also made clear that I would support interventions that could be shown to produce the least overall harm – including lockdowns – and accepted that they were justified when the NHS was not able to deliver all essential services, as happened in both waves.

The unexpected arrival of safe and effective vaccines transformed the situation as lockdowns were now able to actually prevent deaths, and so changed the cost-benefit analysis.

I also realised that earlier cost-benefit analyses for England had not distinguished between the health and economic harms caused by lockdown versus those of coronavirus itself, and updated analyses have now shown that the ‘health harm balance’ is likely to favour lockdown.

The current lockdown has also been more effective than I expected as compliance has remained high – perhaps because the second wave was so much worse than many expected. I know that many are sceptical about the risk of a third wave if restrictions are lifted at the end of April when cohorts 1-9 (all over 50s and those at increased risk) have been offered their first dose.

Although some of the models presented to us over the last year have rightly been criticised, the reasonable worse-case scenario projections presented to SAGE in July on the number of deaths and hospitalisations were remarkably accurate and much closer to the truth than other more optimistic predictions, including mine (I over-estimated how effective voluntary behaviour change would be in preventing a second wave and did not foresee the emergence of the new variant).

So although I do think their projections for the coming summer are overly pessimistic (as they didn’t fully account for seasonality and people’s behaviour change) they cannot be taken lightly.

My own simple calculations show that based on the data we have to date i.e. a 90 per cent take-up and 80 per cent effectiveness from one dose against hospital admissions (which is the key metric in relation to the NHS being overwhelmed) the projections for up to 5000 daily hospital admissions and 500,000 in total until the end of 2022 (roughly the same number we have had so far) are possible in the scenario where peoples contacts went back to pre-covid levels as about 30 per cent of groups 1-9 (about eight million people) would still be at risk.

Two key uncertainties remain – how effective the vaccine will be at reducing transmission with estimates ranging from 30 per cent to 90 per cent and how many contacts people will go back to having once restrictions are lifted.

It is of course unlikely that we would reach that level because as Covid increases, behaviour changes and new restrictions would come in – but this is exactly what we are trying to avoid. And if sufficient numbers of the unvaccinated are not ready to go out because of fear, the economy will not recover as quickly. (About 40 per cent of adults remain worried about catching the virus, despite 50 per cent being vaccinated.)

It is also now clearer (certainly with the new variant) that voluntary changes to behaviour were not sufficient to prevent second (and third waves) and what is happening in Europe with new lockdowns, schools closing and ICUs filling up again is a reminder how easily virus spreads in Spring too (as it did last year)

The experience of Israel is more encouraging, but we need to remember that they first reduced restrictions on February 7 when 80 per cent-of over 60s had received both doses – a milestone we will not reach until June – and that hospital and ICU admissions had only fallen by about 50 per cent one month later.

So while it is true that the rapid progress of vaccination means we are now in a better position than we expected a month ago, we still need to see the impact of each step before taking the next one. And given the remaining uncertainties, we need to get infections as low as possible and vaccinations as high as possible before the next step to minimise the risk of a third wave – with all the direct and indirect health harm that would cause.

I also accept that there need to be strict border controls and quarantines in place until all adults are offered vaccination to reduce the risk of new variants spreading but this cannot go on indefinitely. Vaccines can be adapted to deal with these new variants before the autumn in the same way we do every year with influenza (which actually mutates much more than SARS-CoV2).

We also need to urgently build NHS capacity (particularly in staff) to deal with the huge waiting lists and be prepared for the likely seasonal resurgences of Covid and flu to ensure that this is the last lockdown.

Finally, even for those unconvinced of the arguments above, given that the roadmap will definitely pass, I think it would help with compliance if the public see that Parliament is united behind the roadmap. If compliance falls too far, we could end up with the worst of both worlds: economic and health harms from restrictions and poor control of Covid, as has happened in other countries.

The divisions and polarisation of the last year were perhaps inevitable but I think it is now time to leave those arguments behind. After all, we are all trying to achieve the same thing – to minimise the overall harm to health, the economy, education and society as a result of COVID and the response to it.

I accept that this is not straightforward given the uncertainties that remain. But we have to make a judgment based on the evidence available and I have concluded that the roadmap does achieve that. It thus gives us the best chance of avoiding a third wave, a fourth lockdown and of getting our lives back to normal as quickly as possible.