Effectiveness of Lockdowns

Prior to COVID, the concept of a nationwide lockdown to fight respiratory viruses was not part of pandemic preparedness policies in the U.K.,[1] Ireland,[2] U.S.,[3] Canada,[4] Australia, [5] nor New Zealand.[6] Nor did the World Health Organization recommend such policies. 

In fact, even quarantining 'exposed' people to "reduce transmission is not recommended [by the WHO] because there is no obvious rationale for this measure, and there would be considerable difficulties in implementing it."[7] In the same document, the WHO comes closest to describing what would later be called lockdowns as "timely and sustained application of measures to avoid crowding" and concludes that it "may reduce influenza transmission, although the quality of evidence of its effectiveness is very low."[8]

The U.K.’s ‘Pandemic Preparedness Strategy’ states “it will not be possible to halt the spread of a new pandemic influenza virus, and it would be a waste of public health resources and capacity to attempt to do so.” The document continues, "There is very limited evidence that restrictions on mass gatherings will have any significant effect on influenza virus transmission."[9]

The scientific literature supporting lockdowns is nonexistent prior to COVID. One study in 2006 examined the concept of lockdowns and concluded that "the negative consequences… are so extreme” that this measure “should be eliminated from serious consideration.”[10]     

In March 2020 the British government announced a drastic change in policy based on the computer models produced by Imperial College. Instead of adhering to years of science-based pandemic response, the government was going to impose lockdowns as a means of controlling the new respiratory virus. At the announcement, Neil Ferguson, an epidemiologist at Imperial College set the standard for success, saying, “The aim now is not to slow the rate of growth of cases, but pull the epidemic in reverse.”[11]

Actual Effectiveness

Lockdowns or stay-at-home orders ended up being one of the most dramatic responses used by governments to fight COVID. After being used in Wuhan, China, numerous Western countries started adopting lockdown policies in an effort to reduce virus spread, protect the healthcare system from being overwhelmed, and ultimately reduce deaths. In order to evaluate the success of the policy, its efficacy needs to be determined and then measured against the costs.

Numerous studies have been published to determine how effective lockdown policies were. 

Details are in the caption following the image

Source: https://onlinelibrary.wiley.com/doi/10.1111/biom.13462 

One study[12] stated that “[the] data strongly suggest that the decline in infections in the United Kingdom began before the first full lockdown.”[13] The study shows this to be the case in the two following lockdowns as well. In other words, the virus reduced its rate of infection without a lockdown on all occasions. Arguing that lockdowns were effective at reducing virus transmission is largely based on comparisons to predictive models, and not on empirical data, the study concluded.[14]

Another study evaluating the effects of shelter-in-place (SIP) policies during the COVID pandemic states, “We do not find detectable effects of these policies on disease spread or deaths.” The study concluded that there is currently no compelling evidence to suggest that SIP policies saved a large number of lives or significantly mitigated the spread of COVID.”[15]

Another study compared different countries that implemented mandatory stay at home orders versus countries that did not. This study looked at the possible effects on COVID cases. It concluded that “we do not find significant benefits on case growth of more restrictive NPIs [non-pharmaceutical interventions].”[16] A similar conclusion was drawn by a study that compared different counties in the U.S. and concluded that “Lockdowns are ineffective at reducing COVID deaths.”[17]

If lockdowns do not account for different COVID outcomes, what factors may account for different outcomes? A study published in the Frontiers of Public Health found that location, wealth, and higher life expectancy were associated with higher COVID deaths, but the “stringency of the measures settled to fight pandemia, including lockdown, did not appear to be linked with death rate.”[18]

A study published in The Lancet concluded that “government actions such as border closures, full lockdowns, and a high rate of COVID testing were not associated with statistically significant reductions in the number of critical cases or overall mortality.”[19]

Below is an annotated list of over 30 studies showing the ineffectiveness of lockdowns.  

Two meta-analyses were conducted to examine studies that supported lockdowns and ones that didn't. One published in January 2022 by Johns Hopkins University analyzed 24 studies and concluded that "lockdowns have had little to no effect on COVID-19 mortality." In addition, the study warned that "while this meta-analysis concludes that lockdowns have had little to no public health effects, they have imposed enormous economic and social costs where they have been adopted. In consequence, lockdown policies are ill-founded and should be rejected as a pandemic policy instrument."[20]

Another meta-analysis published in September 2021 of over 100 studies on the costs/benefits of lockdowns concluded that “it is possible that lockdown will go down as one of the greatest peacetime policy failures in modern history.”[21]

 

The Science

Lockdown Effects on Sars-CoV-2 Transmission – The evidence from Northern Jutland, Kepp, 2021

“Analysis shows that while infection levels decreased, they did so before lockdown was effective, and infection numbers also decreased in neighbour[ing] municipalities without mandates…direct spill-over to neighbour[ing] municipalities or the simultaneous mass testing do not explain this…data suggest that efficient infection surveillance and voluntary compliance make full lockdowns unnecessary.”

 

A country level analysis measuring the impact of government actions, country preparedness and socioeconomic factors on COVID-19 mortality and related health outcomes, Chaudhry, 2020

“Analysis was conducted to assess the impact of timing and type of national health policy/actions undertaken towards COVID-19 mortality and related health outcomes….in our analysis, full lockdowns and wide-spread COVID-19 testing were not associated with reductions in the number of critical cases or overall mortality.”

 

Full lockdown policies in Western Europe countries have no evident impacts on the COVID-19 epidemic, Meunier, 2020                               

“Extrapolating pre-lockdown growth rate trends, we provide estimates of the death toll in the absence of any lockdown policies and show that these strategies might not have saved any life in western Europe. We also show that neighboring countries applying less restrictive social distancing measures (as opposed to police-enforced home containment) experience a very similar time evolution of the epidemic.”

 

Effects of non-pharmaceutical interventions on COVID-19: A Tale of Three Models, Chin, 2020

“Inferences on effects of NPIs are non-robust and highly sensitive to model specification. Claimed benefits of lockdown appear grossly exaggerated.”

 

Assessing mandatory stay-at-home and business closure effects on the spread of COVID-19, Bendavid, 2020

“Assessing mandatory stay-at-home and business closure effects on the spread of COVID-19…we do not find significant benefits on case growth of more restrictive NPIs. Similar reductions in case growth may be achievable with less-restrictive interventions.” 

"In the framework of this analysis, there is no evidence that more restrictive nonpharmaceutical interventions (‘lockdowns’) contributed substantially to bending the curve of new cases in England, France, Germany, Iran, Italy, the Netherlands, Spain or the United States in early 2020.”

 

Was Germany’s Corona Lockdown Necessary? Kuhbandner, 2020

“Official data from Germany’s RKI agency suggest strongly that the spread of the corona virus in Germany receded autonomously, before any interventions become effective. 

 

A First Literature Review: Lockdowns Only Had a Small Effect on COVID-19, Herby, 2021

“Lockdowns Only Had a Small Effect on COVID-19…studies which differentiate between the two types of behavioral change find that, on average, mandated behavioral changes accounts for only 9% (median: 0%) of the total effect on the growth of the pandemic stemming from behavioral changes. The remaining 91% (median: 100%) of the effect was due to voluntary behavioral changes.” 

 

Modeling social distancing strategies to prevent SARS-CoV2 spread in Israel- A Cost-effectiveness analysis, Shlomai, 2020                               

“A national lockdown has a moderate advantage in saving lives with tremendous costs and possible overwhelming economic effects.”

 

Lockdowns and Closures vs COVID – 19: COVID Wins, Bhalla, 2020

". . . we also test, in some detail, the hypothesis that early lockdowns, and more stringent lockdowns, were effective in containing the virus. We find robust results for the opposite conclusion: later lockdowns performed better, and less stringent lockdowns achieved better outcomes.” 

“For the first time in human history, lockdowns were used as a strategy to counter the virus. While conventional wisdom, to date, has been that lockdowns were successful (ranging from mild to spectacular) we find not one piece of evidence supporting this claim.”

 

SARS-CoV-2 waves in Europe: A 2-stratum SEIRS model solution, Djaparidze, 2020

“Found that 180-day of mandatory isolations to healthy <60 (i.e. schools and workplaces closed) produces more final deaths…”

 

Government mandated lockdowns do not reduce Covid-19 deaths: implications for evaluating the stringent New Zealand response, Gibson, 2020           

“Lockdowns do not reduce Covid-19 deaths. This pattern is visible on each date that key lockdown decisions were made in New Zealand. The apparent ineffectiveness of lockdowns suggests that New Zealand suffered large economic costs for little benefit in terms of lives saved.”

 

Did Lockdown Work? An Economist’s Cross-Country ComparisonBjørnskov, 2020

Comparing weekly mortality in 24 European countries, the findings in this paper suggest that more severe lockdown policies have not been associated with lower mortality. In other words, the lockdowns have not worked as intended.”

 

Inferring UK COVID-19 fatal infection trajectories from daily mortality data: were infections already in decline before the UK lockdowns ?, Wood, 2020

“A Bayesian inverse problem approach applied to UK data on first wave Covid-19 deaths and the disease duration distribution suggests that fatal infections were in decline before full UK lockdown (24 March 2020), and that fatal infections in Sweden started to decline only a day or two later. An analysis of UK data using the model of Flaxman et al. (2020, Nature 584) gives the same result under relaxation of its prior assumptions on R.”

 

The illusory effects of non-pharmaceutical interventions on COVID-19 in Europe, Homburg, 2020

“We show that their methods involve circular reasoning. The purported effects are pure artefacts, which contradict the data. Moreover, we demonstrate that the United Kingdom’s lockdown was both superfluous and ineffective.”

 

The end of exponential growth: The decline in the spread of coronavirus  Ben-Israel, 2020

“Given that the evidence reveals that the Corona disease declines even without a complete lockdown, it is recommendable to reverse the current policy and remove the lockdown.”

 

The effect of interventions on COVID-19 Soltesz, 2020

"Although the (Non-Pharmaceutical Interventions) NPIs that were considered have indisputably contributed to reducing the spread of the virus, our analysis indicates that the individual effectiveness of these NPIs cannot be reliably quantified."

 

The Mystery of Taiwan, Janaskie, 2020

“Another fascinating outlier – often cited as a case in which a government handled the pandemic the correct way – was Taiwan. Indeed, Taiwan presents an anomaly in the mitigation and overall handling of the Covid-19 pandemic. In terms of stringency, Taiwan ranks among the lowest in the world, with fewer controls than Sweden and far lower than the U.S…. “Despite Taiwan’s closer proximity to the source of the pandemic, and its high population density, it experienced a substantially lower-case rate of 20.7 per million compared with New Zealand’s 278.0 per million. 

 

Impact of non-pharmaceutical interventions against COVID-19 in Europe: A quasi-experimental study, Hunter, 2020 

"Stay at home orders and closure of all non-businesses was not associated with any independent additional impact."

 

Evaluating the effects of shelter-in-place policies during the COVID-19 pandemic, Berry, 2021

“Previous studies have claimed that shelter-in-place orders saved thousands of lives, but we reassess these analyses and show that they are not reliable. We find that shelter-in-place orders had no detectable health benefits.”

 

Four Stylized Facts about COVID-19Atkeson, 2020

“Failing to account for these four stylized facts may result in overstating the importance of policy mandated NPIs for shaping the progression of this deadly pandemic… The existing literature has concluded that NPI policy and social distancing have been essential to reducing the spread of COVID-19 and the number of deaths due to this deadly pandemic. The stylized facts established in this paper challenge this conclusion.”

 

Too Little of a Good Thing A Paradox of Moderate Infection Control, Cohen, 2020

“The link between limiting pathogen exposure and improving public health is not always so straightforward. Reducing the risk that each member of a community will be exposed to a pathogen has the attendant effect of increasing the average age at which infections occur. For pathogens that inflict greater morbidity at older ages, interventions that reduce but do not eliminate exposure can paradoxically increase the number of cases of severe disease by shifting the burden of infection toward older individuals.”

 

Covid Lockdown Cost/Benefits: A Critical Assessment of the Literature, Allen, 2020

“The pattern of daily deaths per million, is not negatively correlated with the stringency of lockdown across countries. Using a cost/benefit method proposed by Professor Bryan Caplan, and using two extreme assumptions of lockdown effectiveness, the cost/benefit ratio of lockdowns in Canada, in terms of life-years saved, is between 3.6–282. That is, it is possible that lockdown will go down as one of the greatest peacetime policy failures in Canada’s history.”

 

Covid-19: How does Belarus have one of the lowest death rates in Europe? Karáth, 2020

“Belarus’s beleaguered government remains unfazed by covid-19. President Aleksander Lukashenko, who has been in power since 1994, has flatly denied the seriousness of the pandemic, refusing to impose a lockdown, close schools, or cancel mass events like the Belarusian football league or the Victory Day parade. Yet the country’s death rate is among the lowest in Europe—just over 700 in a population of 9.5 million with over 73 000 confirmed cases.”

                                                    

States with the Fewest Coronavirus Restrictions, McCann, 2021

"No relationship in stringency level as it relates to the death rates, but finds a clear relationship between stringency and unemployment."

 

The Impact of the COVID-19 Pandemic and Policy Responses on Excess Mortality, Agrawal, 2021         

“Failed to find that countries or U.S. states that implemented SIP policies earlier, and in which SIP policies had longer to operate, had lower excess deaths than countries/U.S. states that were slower to implement SIP policies. We also failed to observe differences in excess death trends before and after the implementation of SIP policies based on pre-SIP COVID-19 death rates.”

 

The Costs and Benefits of Covid-19 Lockdowns in New Zealand, Lally, 2021         

“Using data available up to 28 June 2021, the estimated additional deaths from a mitigation strategy are 1,750 to 4,600, implying a Cost per Quality Adjusted Life Year saved by locking down in March 2020 of at least 13 times the generally employed threshold figure of $62,000 for health interventions in New Zealand; the lockdowns do not then seem to have been justified by reference to the standard benchmark. Using only data available to the New Zealand government in March 2020, the ratio is similar and therefore the same conclusion holds that the nation-wide lockdown strategy was not warranted.”

                                                    

COVID-19 mortalities in England and Wales and the Peltzman offsetting effect, Williams, 2021

“Our results suggest: (i) a refined estimate of mean weekly COVID-19 excess deaths that is 63% of standard excess deaths; and (ii) a positive net excess mortality impact of the lockdown. We make a case that (ii) is due to the Peltzman offsetting effect, i.e. the intended mortality impact of the lockdown was more than offset by the unintended impact.”

 

Progression of COVID-19 under the highly restrictive measures imposed in Argentina, Sagripanti, 2021

“The number of yearly deaths caused by respiratory diseases and influenza in Argentina before the pandemic was similar to the total number of deaths attributed to COVID-19 cumulated on April 25, 2021, more than a year after the pandemic started. The failure to detect any benefit on ameliorating COVID-19 by the long and strict nation-wide lock-downs in Argentina should raise world-wide concerns about mandating costly and ineffective restrictive measures during ongoing or future pandemics.”

 

COVID-19 in South Africa, Broadbent, 2020 

"Contrary to widespread political and popular views, no changes in the shape of the curve can be attributed to the introduction or easing of any regulation at this stage."

 

Hard, not early: putting the New Zealand Covid-19 response in context, Gibson, 2020

“The cross-country evidence shows that restrictions imposed after the inflection point in infections is reached are ineffective in reducing total deaths. Even restrictions imposed earlier have just a modest effect.”

 

Does Social Isolation Really Curb COVID-19 Deaths? Direct Evidence from Brazil that it Might do the Exact Opposite, de Souza, 2020            

“There appears to be strong empirical evidence that, in Brazil, the adoption of restrictive measures increasing social isolation have worsened the pandemic in that country instead of mitigating it, likely as a higher-order effect emerging from a combination of factors.”

 

A Final Report Card on the States’ Response to COVID-19, Kerpen, 2022 

“The outcomes in NJ, NY, and CA were among the worst in all three categories: mortality, economy, and schooling. UT, NE, and VT were leaders in all three categories." 

"Although sometimes criticized as having policies that were “too open,” Florida proved to have average mortality while maintaining a high level of economic activity and 96 percent open schools.”


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Footnotes
[1]: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/213717/dh_131040.pdf
[14]: “The model proposing major benefits from lockdown in European countries had the worse fit to the data

https://www.jclinepi.com/article/S0895-4356(21)00087-1/fulltext

[21]: https://www.tandfonline.com/doi/abs/10.1080/13571516.2021.1976051?journalCode=cijb20