Reintroduction of measures from Da Nang to Auckland is a reminder that once venues reopened/restrictions lifted, cannot assume contact tracing alone will be sufficient to control local transmission (consistent with modelling analysis: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30457-6/fulltext)">https://www.thelancet.com/journals/... 1/

Coverage often focuses on test & trace as if it were a single solution, but it’s one tool of several. Outbreaks globally (e.g. South Korea, Vietnam, Singapore, Hong Kong) show that other measures (restrictions on gatherings, remote working, venue closures) needed alongside. 2/

TTI works better with low case numbers & social distancing, because as outbreaks grow, it& #39;s harder to trace all contacts, and % of transmission that TTI can prevent shrinks. As @mlipsitch puts it, “you don& #39;t clean up an oil spill with paper towels” https://www.nytimes.com/reuters/2020/08/04/world/europe/04reuters-health-coronavirus-tracing-specialreport.html">https://www.nytimes.com/reuters/2... 3/

We need to find ways to reduce risk & reduce disruption of measures, but shouldn& #39;t expect one measure to do all the work. TTI approach has also been different in Asia, so won& #39;t necessarily see same results if implemented differently elsewhere: https://twitter.com/AdamJKucharski/status/1256140519572484102?s=20">https://twitter.com/AdamJKuch... 4/4