Lessons from Covid

Do facemasks work?

In March 2020 England’s deputy chief medical officer, Jenny Harries, advised the public that wearing face coverings was “not a good idea”. Doing so could “actually trap the virus in the mask”. By June there had been a U-turn. Masks were not only a good idea but were mandatory on public transport, in shops and health premises.

And now? The respected Cochrane Review recently concluded that masks “probably make little or no difference” to Covid outcomes. But this says more about the quality of the evidence than masks themselves. It is likely that face coverings reduce the risk of transmission to some degree — and other studies have found that N95-type respirators are far more effective than cloth coverings or surgical masks — but we still do not know by how much.

Antiviral hygiene

In the spring of 2020, hygiene advice went into overdrive. People started worrying whether parcels delivered to their homes might be contaminated with coronavirus. Clothing retailers were told to quarantine returned items for 48 hours. But scientists later concluded that inanimate objects were unlikely to play any meaningful role in the spread of Covid. While microscopic flecks of virus might linger on surfaces for a few days, there was little risk they could be transferred into someone’s lungs. Instead, the virus is spread in tiny aerosol droplets that can stay aloft for hours. Opening a window or two, rather than doing a deep clean, could make all the difference. Infected people spread viral particles when they talk, breathe, cough or sneeze. Social distancing works: exposure to such particles is reduced by between two and 10 times if people are 2m apart compared with 1m.

What about handwashing?

Handwashing is still advisable because of our inescapable habit of putting our hands to our face. The Cochrane Review found good hand hygiene cuts the risk of Covid and other acute respiratory infections by 14 per cent. It did not venture a conclusion on the impact of singing while doing so.