THE curious story of the UK media campaign to reduce the two-metre distancing guidance has involved a long campaign not by researchers in the field but initially by politicians. We have had Iain Duncan Smith making judgements about epidemiology and supporting the reduction. We have had policy wonks pronouncing on hygiene and ventilation studies. We have seen and heard large numbers of “experts” stating the two-metre guidance was based on outdated 1930s studies. Many of the statements made in favour of reduction have been inaccurate or seriously uninformed. The case made for some sort of blanket reduction is not evidence-based so far.

Scientific evidence from the 2020s and not the 1930s and 1940s indicates there is a strong case for supporting and even extending the two-metre social distancing guidance in some circumstances. Current evidence supports the two-metre guidance in many locations, occupations and industries because of airborne as well as large droplet transmission. Past research underestimates viral airborne risks. Evidence from clusters supports more caution. The R rate is still not low enough across the UK for change but it is as low as it is partly because of the two-metre distancing.

There is also still limited evidence to support a reduction below two metres and the latest WHO-funded study on one and two metres is not conclusive and has been attacked as inadequate. Yet even that acknowledges two metres is more protective than one.

Current evidence supports the general importance of the combined use of social distancing, use of masks and other PPE and handwashing, not removing or reducing parts of this strategy. There must also be continued employment, wage protection and suspension of punitive sickness absence and performance management system, to encourage safe practices including self-isolation.

We have not yet seen the review that the Prime Minister apparently used to make his decision. This is not transparent and informed decision-making. In contrast the First Minister has been far more open and, in the circumstances far more cautious, in moving to release the lockdown based on careful evaluation of each step. That makes good public health sense and protects the economy too to ensure public safety and no unforeseen spikes and damaging new waves of covid-19.

Professor Andrew Watterson,

Occupational and Environmental Health Research Group, Public Health and Population Health Research Group,

University of Stirling.

I WAS disturbed to see the picture on Monday's front page of a family reunited (The Herald, June 22). Although the caption is correct about the meeting of two different households, the guidance clearly states that social distancing should be maintained. For your paper to show such a breach is irresponsible; however, it shows that even you don't understand the mixed messages coming from our Scottish Government.

Kenneth Morin, Newton Mearns.

MONDAY'S front-page picture depicts a serious breach of the social distancing and other guidance issued by the Scottish Government and in effect at the time. This is a disservice and a health risk to your readers and undermines the admirable efforts of the First Minister to limit the fatalities and socio-economic effects of the current pandemic.

Charles Shaw, Glasgow G73.

Editor’s note: Social distancing rules apply except when an extended household is formed. Only people living alone (or those living only with children) can form an extended household with members of one other household. People who have been advised to shield should not form an extended household.

We did not make the specific household circumstances clear in either the picture or caption and apologise for any confusion it may have caused.