The Impact of Reopening and the Lifting of COVID-19 Restrictions

Last Updated: May 12, 2021

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This Briefing Note was completed by the Research, Analysis, and Evaluation Branch (Ministry of Health) based on information provided by members of the COVID-19 Evidence Synthesis Network. Please refer to the Methods section for further information.


This briefing note provides a summary on the impact of reopening and the lifting of COVID-19 restrictions.

*The full version of the Briefing Note including the Appendix can be accessed in the PDF file at the top of the page*

Key Findings and Implications

How Restrictions are Lifted:

The Order of Lifting Restrictions:

The Impact of Lifting Restrictions:

Implications for Ontario

Supporting Evidence

This section below summarizes scientific evidence and jurisdictional experiences on the impact of reopening and the lifting of COVID-19 restrictions. In terms of jurisdictional experience, information is presented on Australia, Canada (British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Nova Scotia, Prince Edward Island, Newfoundland and Labrador, Yukon, Northwest Territories, Nunavut), Chile, China, Denmark, England, France, Germany, India, Ireland, Israel, New Zealand, the United Kingdom (UK), and the United States (US). At this time, there is limited information published on the actual, observed impacts and unintended negative consequences of reopening or lifting public health measures during the COVID-19 pandemic.

Scientific Evidence

How Restrictions are Lifted:

  • Most scientific evidence based on modelling studies suggest that reopening or lifting of COVD-19 restrictions are dependent on the case rates and the progress of vaccination programs. It is generally suggested that gradual release strategies (i.e., ending lockdowns through multiple staggered releases) are effective to avoid resurgence of COVID-19 waves.

The Order Restrictions are Lifted:

  •  No information identified.

Impact of Lifting Restrictions:

  • Modelling study evidence suggests that public health measures (i.e., social distancing, increased testing) should be implemented alongside a gradual release of strategies. For example:
    • A modelling study quantifying the pace at which European countries can lift restrictions without overwhelming their health-care systems reported that any premature lifting of restrictions may cause another wave with high COVID-19 incidence and ICU admissions. Early relaxations can significantly increase morbidity and mortality rates, as a fraction of the European population has not been vaccinated and thus remains susceptible.
    • A modelling study examining the effectiveness of lockdown on SARS-CoV-2 epidemic progression in New Zealand, France, Spain, Germany, the Netherlands, Italy, the UK, Sweden, and the US indicated that an early-onset lockdown followed by gradual de-confinement resulted in a rapid reduction in COVID-19 cases and a rapid recovery time compared with other countries that had an abrupt de-confinement period which resulted in a prolonged plateau of COVID-19 infections, with elevated R0 and non-ending recovery.
    • A modelling study examining the efficacy of two potential lockdown release strategies, using the UK population as a test case, concluded that to prevent the recurring spread of COVID-19, a gradual release strategy is preferable to an on- off release strategy (i.e., lockdown is lifted for the entire population simultaneously, but can subsequently be reinstated when necessary). Specifically, the study suggests releasing approximately half the population two to four weeks from the end of an initial infection peak, then waiting another three to four months to allow for a second peak before releasing everyone.

International Scan

How Restrictions are Lifted:

  • Case rates remain the major determining factor for lifting public-health measures for most countries, regardless of the level of vaccination;
  • China’s CDC, in particular, recommends that prevention and control measures should continue to be implemented to prevent a resurgence of the pandemic, considering the time required to produce protective antibodies for individuals, limited protective effect of COVID-19 vaccines for individuals, and the possibility of transmission when herd immunity has not yet been built;
  • Israel introduced new measures for vaccinated residents once the proportion of the population received at least one dose of COVID-19 vaccine surpassed 50%; and 
  • In the US, several states have reportedly lifted restrictions based on high rates of vaccination and decreasing rates of hospitalizations.

The Order Restrictions are Lifted:

  • Most countries have not indicated how they will lift public-health measures for vaccinated individuals or once specific proportions of their populations are vaccinated, with the exception of Israel and the US which have increased their vaccination rates significantly within the last two months;
  • In Israel, a “Green Pass” system was introduced in late February 2021 that allows fully vaccinated (one week after last dose) or those recovered from COVID-19 to enter specific businesses with a “green pass/certificate” and photo ID and as of March 7, 2021, fully vaccinated Israeli residents do not have to quarantine after entering the country;
  • Israel has announced mutual agreements with both Cyprus and Greece which allow fully vaccinated Israeli residents to travel freely between these countries;
  • On 9 March 2021, the US CDC announced modified public-health measures for fully vaccinated individuals in the US that permit indoor gatherings with other fully vaccinated people without wearing masks, indoor gatherings with unvaccinated people from one other household without masks if none of the unvaccinated individuals have an increased risk of severe illness from COVID-19, and routine activities even if the individual has been around someone with COVID-19 (unless they have symptoms or live in a group setting); and
  • The US CDC’s recommendations for fully vaccinated people were updated on March 10, 2021 with changes to visitation restrictions of post-acute care facilities and work restriction policies for asymptomatic health care personnel, and quarantine policies for asymptomatic residents and patients.

Impact of Lifting Restrictions:

  • The United Kingdom (up to Dec 31, 2020) and Chile showed rapid and uncontrolled case growth, hospitalizations, and re-introduction of stricter public health measures or postponement of further reopening after COVID-19 restrictions were lifted. Variants of concern were the dominant strains of SARS-CoV-2 in these jurisdictions (UK B.1.1.7, and Chile P.1 lineage).

Canadian Scan

How and What Order Restrictions are Lifted:

  • Canada’s Federal/Provincial/Territorial Special Advisory Committee on COVID-19 provided guidelines for a measured approach to easing public-health restrictions since April 2020, however, these guidelines have not been revised considering vaccination-related factors;
  • Most provincial reopening plans had been developed prior to vaccine roll-out and benchmark the lifting of public-health measures on COVID-19 case numbers and hospitalizations, at least until there is evidence that vaccinations are having an impact on these factors within their populations; and
  • All provincial governments have indicated that vaccinated individuals must continue to follow public-health measures.

Ontario Scan

How Restrictions are Lifted:

  • No information identified.

The Order Restrictions are Lifted:

  • From February 10–March 8 Public Health Units moved into various tiers of a re-opening framework. In 21 health units, the incidence was above 25 to 39.9 per 100,000 seven day average during the week of March 6.

 Impact of Lifting Restrictions:

  • Ontario (up to Dec 31, 2020) showed rapid and uncontrolled case growth, hospitalizations, and re-introduction of stricter public health measures or postponement of further reopening after COVID-19 restrictions were lifted. Variants of concern were the dominant strains of SARS-CoV-2 in these jurisdictions (Ontario B.1.1.7)


The COVID-19 Evidence Synthesis Network is comprised of groups specializing in evidence synthesis and knowledge translation. The group has committed to provide their expertise to provide high-quality, relevant, and timely synthesized research evidence about COVID-19 to inform decision makers as the pandemic continues. For more information, please contact the Research, Analysis and Evaluation Branch (Ministry of Health).