Based on the results at the time, WHO did not recommend travel restrictions when it declared COVID-19 a Public Health Emergency of International Concern (PHEIC). The 2020 decision in Taylor v. Newfoundland and Labrador[7] (“Taylor”) provides a useful starting point for what is possible and the constitutional basis behind these restrictions. The Supreme Court of Newfoundland and Labrador ruled in Taylor that provinces may, in appropriate circumstances, legally impose restrictions on interprovincial travel, including a complete ban on certain non-essential travellers from other provinces. This decision provides useful guidance on how these restrictions may be interpreted by the courts and provides an insightful analytical framework for reviewing the constitutionality of these laws. Provinces that intend to maintain COVID-19 travel restrictions will undoubtedly follow the Taylor decision. To date, Do Not Embark and Lookout lists have been used for people with suspected or confirmed infectious tuberculosis (TB), including multidrug-resistant TB (MDR-TB) and measles. However, travel restrictions can also be used for other suspected or confirmed communicable diseases that could pose a threat to public health while travelling, including viral haemorrhagic fever such as Ebola. We identified 29 studies, of which 26 were modelled. Thirteen studies examined international measures, while 17 examined national measures (one examined both). There was general agreement that the introduction of travel measures has led to significant changes in the dynamics of the early stages of the COVID-19 pandemic: the Wuhan measures have reduced the number of cases exported abroad by 70% to 80% and have led to a significant reduction in transmission in mainland China.

Additional travel measures, including flight restrictions to and from China, may have resulted in a further decrease in the number of exported cases. Few studies have examined the effectiveness of interventions implemented in other settings. Early implementation was identified as a determinant of effectiveness. Most studies of international travel measures have not accounted for domestic travel measures, which likely led to biased estimates. Although this study identified a relatively large number of studies, we consider the quality of these studies to be low overall. Almost all of the studies identified in this review were modelled studies and therefore the results depend on assumptions of important endpoints that varied considerably. Given the rapidly evolving and dynamic nature of the pandemic, it is difficult to know how close these assumptions were to reality. Comparability between studies is also compromised by the lack of standardized terminology. In addition, few studies have sought to isolate the potential impact of international travel measures from a series of competing national measures or from other social, political or economic characteristics of implementation, destination or population groups.

Outcomes included number of observed cases, peak date of the outbreak, risk of transmission, rate of case growth, doubling time, time of arrival in a new country, number of reproduction (R0 or Rt) and projected cumulative cases. Details are provided in Tables 2 and 3, which summarize documents examining measures of international and domestic travel, respectively. An article evaluating the effectiveness of both types of interventions28 is included in both tables. Table 2 summarizes the evidence generated by documents examining the impact of international travel measures. All but one30 were modelled studies. Four studies directly examined the impact of the Wuhan travel ban on the initial international export of cases.28 31–33 By comparing the observed number of exported cases with modelled estimates based on scenarios without the ban, the studies consistently found that these measures were highly effective in reducing the export of cases. Among the studies examining the impact of the Wuhan travel measures, there was a consensus that the measures resulted in a 70% to 77% decrease in the number of cases exported abroad in early February: Anzai et al.31 estimated a 70% decrease in cases exported worldwide in the week following the introduction of the ban. Chinazzi et al.28 estimated that the ban had led to a 77% decrease in imported cases, while Wells et al.32 estimated that it had reduced the number of exported cases by 70.5% by mid-February. However, Kucharski estimated that transmission rates outside China were reduced by about half within 2 weeks of the ban being imposed.33 To conduct this review, we adopted an abbreviated version of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) protocol using the 17-point checklist.23 The rationale for the study was the widespread introduction of travel measures, despite the consensus at the time that these measures were largely ineffective and strengthened the application of the IHR during this and subsequent pandemics. The aim was to quickly examine the effectiveness of all travel measures taken at the beginning of the COVID-19 pandemic, based on published and unpublished studies. We will continue to discuss other methods of the study.

Second, most studies also agreed that the impact of Wuhan-specific measures was short-lived, in part because over time, other provinces became the source of most of China`s internationally exported cases. This suggests that narrowly targeted travel-related measures against specific countries may not be sufficient on their own, as knowledge of where a new virus is circulating may be limited from the outset and countries should start implementing national public health measures in addition to international travel measures. This view is also supported by the evidence identified in this review, which suggests that after four or more infections are introduced into a new site, there is a greater than 50% chance of a major outbreak occurring (unless other interventions are taken).33 limitations on the rights guaranteed in subsection 6(2); which are listed in Article 6(3) and (4) are not exhaustive, since Article 6(2) is also subject to Article 1 (Black, cited above, paragraph 68). Third, this study reveals that measures implemented early were likely to be more effective than those implemented late. In this pandemic, the PHEIC statement was only issued after many countries began taking travel measures, and when they did, WHO recommended against taking such measures. In addition, the IHR require States Parties to provide evidence of the additional sanitary measures they are implementing. In the context of an outbreak of a new infectious disease pathogen, it is not clear what constitutes evidence in the early stages of the outbreak. The importance of evidence, especially when it is unlikely to exist, must be weighed against the potential risk and the need for early containment measures.

The Canadian government has its own testing, quarantine and entry restrictions in addition to Newfoundland and Labrador`s provincial requirements. Please check and complete them carefully as described on the following link: Beyond the direct effect of the Wuhan travel ban, Chinazzi et al.28 considered that the application of additional travel-related restrictions, namely the reduction of flights between mainland China and destination countries, has resulted in a further significant reduction in imported cases worldwide, although the magnitude of the country-to-country reduction and the magnitude of the Flight reductions varied.