A sub-lineage of the omicron coronavirus variant, dubbed BA.2, continues to increase steadily around the globe as scientists and health officials are still working to understand the risk it poses to public health.

So far, the overall data has been a mix. Some recent laboratory and animal data have suggested that BA.2 can cause more severe disease than the original omicron variant, BA.1. But, so far, that finding isn’t bearing out in real-world data. Countries where BA.2 is dominant are not seeing higher rates of severe disease. And, many places seeing BA.2 increasing are also seeing cases decline, along with hospitalizations.

While animal experiments have hinted that BA.2 interacts differently to some immune responses than the original omicron variant, so far real-world vaccine data finds two doses and booster doses are just as effective—if not slightly more effective—against BA.2 than BA.1.