Monaz: Hello, I'm Monaz Mehta, editor in the Cochrane Editorial and Methods department. COVID-19 has spread quickly throughout the world, and Cochrane is preparing a series of rapid reviews of the evidence to help decision makers with their response. In this podcast, lead author, Jake Burns from the University of Munich in Germany describes the findings of our review of the effects of travel-related control measures, which was published in September 2020.

Jake: Travel-related control measures, even as they’ve been implemented during the COVID-19 pandemic, can refer to many things, but we focused specifically on restrictions that reduce cross-border international travel. These include measures such as border closures or restricting entry for people from high-risk countries, screening of travelers upon departure or arrival, by asking about symptoms, measuring temperature or testing for the virus, and the quarantine of travelers. We were interested in whether these measures led to cases of COVID-19 being avoided or a shift in the development of the epidemic. We also wanted to know how many cases of COVID-19 were detected because of each control measure.
Our extensive searches over the last few months identified 36 eligible studies, which included both mathematical modelling and observational studies.
There are substantial differences between these studies with regard to the countries involved, the specific control measures that were looked at and how these were implemented, and also how the studies were conducted. This makes it quite challenging to draw general conclusions about effectiveness but we did observe some trends. 
Travel restrictions reducing cross-border travel, like the closure of borders and restricting travelers from high-risk countries, may help to contain the COVID-19 pandemic. However, screening and subsequent testing of travelers with symptoms, on its own, seems unlikely to be effective. But, if symptom screening is combined with additional measures, such as quarantine, observation and repeated testing, the effectiveness will likely improve.
Despite these promising findings, there are some important caveats to keep in mind. For a variety of reasons, which include the methods applied in the studies we reviewed and how complete a picture of the evidence base as a whole that they provide, the certainty of the evidence is quite low. This means that although some of the studies were quite well conducted, our confidence in the overall results is limited. So, although some evidence does exist to help support decision makers, there are still important questions that need to be answered. And, as the pandemic progresses, researchers and decision makers need to work together to prioritize the most urgent and context-appropriate questions to answer, in order to resolve these uncertainties.

Monaz: If you would like to read the full review, and watch for updates as new evidence becomes available it’s available free online. Just visit Cochrane Library dot com and search 'travel restrictions and COVID-19'.