Lockdowns reduce infection rates, but only for a few weeks

Peter Baume makes out a robust but general case (in Online Opinion24^th August) against Sonia Bowditch on the basis of the ethical principle of consequentialism, maintaining that 'most effective public health measures have been coercive'.

However, he advances no specific evidence to demonstrate that lockdowns in fact achieve the consequences that are intended.

As it happens, a comprehensive study has recently been published in the world's top medical journal, The Lancet, that shows that lockdowns have an effect on infection rates, but only in the short term. The authors (Kephart et al) reviewed the evidence from 314 Latin American cities looking for an association between reduced mobility (the key factor that lockdowns are supposed to produce) and infection rates.

They concluded that: '10% lower weekly mobility was associated with 8·6% (95% CI 7·6–9·6) lower incidence of COVID-19 in the following week. This association gradually weakened as the lag between mobility and COVID-19 incidence increased and was not different from null at a 6-week lag.'

So, lockdowns reduce infection rates, but only for a few weeks, not for any meaningful period. And research studies have not found associations between lockdowns and reduced mortality outcomes over the course of an epidemic wave.

The findings of the study on Latin American cities are entirely consistent with the advice of the World Health Organisation, which has maintained its position from before the COVID-19 pandemic. In its first Strategic Preparedness and Response Plan for the pandemic dated February 2020, it maintained:

Evidence has shown that restricting the movement of people and goods during public health emergencies may be ineffective, and may interrupt vital aid and technical support, disrupt businesses, and have a negative impact on the economies of affected countries and their trading partners. However, in certain specific circumstances, such as uncertainty about the severity of a disease and its transmissibility, measures that restrict the movement of people may prove temporarily useful at the beginning of an outbreak to allow time to implement preparedness activities, and to limit the international spread of potentially highly infectious cases. In such situations, countries should perform risk and cost-benefit analyses before implementing such restrictions, to assess whether the benefits outweigh the drawbacks.

The February 2021 edition of the Plan does not include lockdowns at all in the recommended public health measures to suppress transmission (see infographic on p11).

There is now detailed specific evidence for COVID-19 that supports the long-established WHO position. Governments need to explain why they have contravened WHO's evidence-based recommendations by repeatedly imposing lockdowns for months at a time, causing considerable collateral damage, the evidence for which is being collated at the website Collateral Global.

It is not acceptable for governments to impose harsh measures which restrict basic human rights and directly impose harms, without justifying them in the form of evidence-based risk and cost-benefit analyses as called for by the WHO, and these should be made public.