---
title: Behavioural Measures Controlling Covid
tags: live-v0.1, behaviour, policy, social norms
permalink: https://c19vax.scibeh.org/pages/c19behaviour
---
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# The success of behavioural measures in controlling COVID-19

## The scientific consensus and behavioral measures

<span style="color:green">Pre-vaccination, the only effective measures to control the pandemic were behavioral</span>: mask-wearing, physical distancing, hand hygiene, accompanied by testing and tracing.

These behavioral measures helped control the spread of the virus and in some cases even eliminated the virus from countries <span style="color:green"> for long periods of time</span>. For example, in New Zealand the government decided early on to eliminate the virus and implemented a strict nationwide lockdown on 26 March 2020. In early May, the last known case was identified, which marked the end of known community spread. On 8 June 2020, the New Zealand government effectively declared the pandemic over, 103 days after the first identified case ([Baker et al., 2020](https://dx.doi.org/10.1056/nejmc2025203)). A subsequent outbreak in August 2020, too, was [brought under control](https://www.nytimes.com/2020/10/07/world/australia/new-zealand-coronavirus.html) by October 2020.

There <span style="color:green">was widespread </span>[scientific consensus](https://www.johnsnowmemo.com/) at the time that behavioral measures were a necessary component of any strategy to control the pandemic until the vaccine became widely administered ([Alwan et al., 2020](https://dx.doi.org/10.1016/S0140-6736(20)32153-X)). <span style="color:green">Because a large proportion of people who catch COVID-19 would need intensive hospital care, [a natural, extreme herd immunity approach would be overwhelming for hospitals](https://www.theguardian.com/world/2021/may/28/a-look-at-prof-gowers-herd-immunity-document-sent-to-dominic-cummings). Behavioural measures consequently remained relevant to control the spread and help healthcare systems cope. </span>
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[REF: [@Bromfield20; @Summers20]. However, physical distancing and the social isolation it entails also have adverse consequences for people’s mental health [REF: @EveryPalmer20; @Serafini20; @Xiong20] and livelihoods [REF: @Bartik20; @Bonaccorsi20].--->

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## Vaccines and other health protective measures

Despite vaccines, health-protective behaviors <span style="color:green">have remained relevant to varying degrees depending on context.</span> New viral strains may keep this a live issue [(Paltiel et al., 2020](https://dx.doi.org/10.1377/hlthaff.2020.02054)).

## Details of effectiveness of behavioral measures

The effectiveness of behavioral measures to control the pandemic was examined in a large study by [Haug et al. (2020)](https://dx.doi.org/10.1038/s41562-020-01009-0). The researchers considered more than 30,000 interventions (e.g., laws to enforce social distancing or other policy measures) in nearly 250 countries and jurisdictions.

Their main results are shown in the figure below.


In the figure, the effects of various interventions on the change in "reproductive number" (_R_) are rank-ordered from most effective to least effective (top to bottom). The reproductive number is a crucial indicator of the spread of a pandemic: a value >1 implies that the virus is increasing its spread whereas a value <1 implies that the pandemic has been brought under control and the spread is decelerating. Thus, the more successful a measure is in the figure above, the more it will be to the left of 0, implying that it successfully reduced the value of _R_.

The largest impacts on _R_ resulting from strictly behavioral measures were found to be:
* small gathering cancellations (reduction in _R_ between −0.22 and –0.35)
* closure of educational institutions (reduction in _R_ between −0.15 to −0.21)
* border restrictions (−0.057 to –0.23).
* individual movement restrictions (−0.08 to −0.13)
* national lockdowns (−0.008 to −0.14)
* wearing masks (−0.018 to –0.12; not shown in the figure)

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