No one expects BA.2 to affect the United States as drastically as it has Hong Kong. But some experts believe that a “stealth” variant surge may happen in the United States, like it already has started to do in Europe.
By mid-March 2022, BA.2 was the cause of 68.6% of cases in the United Kingdom and more than 50% of cases in several other European countries. Daily cases were rising in more than half of the countries in the European Union.
Some experts believe that a 50% rate can be seen as a “tipping point.” A tipping point is the rate where a subvariant (such as BA.2) starts to cause more widespread, serious disease.