In all the uncertainty about a new virus variant, omicron, a bright spot must not be overlooked. The new variant was detected and its genome sequenced rapidly in South Africa, which then alerted the rest of the world that it carried a large number of mutations and might be more transmissible, virulent and immune evasive than previous variants. For this stellar and generous performance, South Africa was met with the sound of doors slamming shut.

What scientists did in South Africa is deliver a glimpse of the future we need: a global early-warning system, using genomic surveillance, to spot and track the changes and spread of pathogens based on whole-genome sequencing that produces a genetic blueprint made up of the very smallest building blocks of life. The data can be shared rapidly and used to develop therapies and vaccines. This surveillance does not exist yet on a global scale, but South Africa and Britain have demonstrated its immense promise.

The South African president, Cyril Ramaphosa, learned of the new variant from Tulio de Oliveira, founding director of the Center for Epidemic Response and Innovation, who has been outspoken during the pandemic about the need to use the tools of viral genomics for early warning and tracking. When omicron began showing up in new cases on Nov. 11, South Africa was ready — in June 2020, it had set up the Network for Genomic Surveillance in South Africa, linking laboratories and their associated academic institutions. The South African network quickly compared the genome of the new variant with others — discovering the large number of mutations, including on the spike protein that enables entrance to human cells — and then shared it with the World Health Organization and scientists around the globe.

Ideally, such networks should be on guard everywhere and at all times. The United States has been improving its use of genomic surveillance to track variants during the pandemic but still lags other nations. The need for global cooperation in public health — a theme of this week’s special session of the World Health Assembly — has often been hampered by nations’ refusal to share samples and data, by patchwork funding for surveillance, and by scattered epidemiological and clinical information that is disconnected from genomics, making it harder to connect the dots. The Rockefeller Foundation has announced it will invest part of a recent $1 billion commitment to help establish a broad platform to overcome these hurdles.

Travel bans announced in the wake of omicron’s discovery might slow transmission slightly, but they ultimately penalize nations with struggling economies such as South Africa. Far more urgent is the need to accelerate vaccination in the United States and worldwide. In the coming weeks, scientists will determine whether omicron’s mutations signal new threats, even as the delta variant is still ravaging the United States and the world. It is time to begin leveraging genomics and information-sharing to build a powerful and robust global radar for disease. Otherwise, we will be flying blind into yet another dangerous storm.