The power of diagnostics information ( VODI ) to public health and society was a topic of keen interest even before the COVID-19 outbreak. The pandemic offers us fresh lessons on how health systems can harness this value. Many of us will recall one of the earliest recommendation from the Director General of the WHO during the pandemic: test, test, test . In our view, testing played a key role in healthcare systems’ response to COVID-19. From the earliest weeks of the pandemic, Germany and South Korea stood out in managing outbreaks relatively well. Besides having very resilient healthcare systems with high laboratory capacity and trained staff, they were also doing better than most countries because they had the resources to test widely at an early stage. As a consequence they have also suffered lower case fatality rates than comparable countries. Despite the rapid development of diagnostic tests, most countries lacked the necessary personnel, equipment, and infrastructures to be able to cover the needs caused by the surge of severe COVID-19 cases. Yet, the wide deployment of diagnostics has helped to control this surge in countries which supported appropriate reimbursement policies for diagnostics and antibody tests. Social measures, including the design of lockdown protocols and the progressive return to the “new normal”, have been informed by the effectiveness with which diagnostics were deployed. Border policy has been linked to the availability of, and free access to, rapid testing at airports. This has been facilitated in some high-income countries such as Denmark, and in some low- and middle-income countries, such as Senegal. So, how can we better harness the value of diagnostic information for more personalized care in future? The urgency of controlling the surge of COVID-19 cases has made it necessary to prioritise the immediate consequences of the tests, those...