The World Health Organization has classified a new COVID-19 variant, designated LB.4, as a variant of interest after it rapidly became the dominant strain in Germany, France, and the United Kingdom. Initial data suggests that LB.4 is approximately 12 percent more transmissible than previous variants but causes milder symptoms in most patients.
"We are monitoring the LB.4 variant closely, and while it does appear to spread more easily, the clinical picture remains encouraging," said WHO COVID-19 Technical Lead Dr. Maria Van Kerkhove. "Vaccination and prior infection continue to provide significant protection against severe disease."
The variant has been detected in 38 countries, including 18 states in the United States, where it accounts for approximately 9 percent of new cases. The Centers for Disease Control and Prevention expects LB.4 to become the dominant variant in the U.S. within four to six weeks.
Pfizer and Moderna have announced that updated booster vaccines, currently in distribution for the fall season, have shown effectiveness against LB.4 in laboratory testing. "The existing booster formulation provides meaningful protection against this variant," said Pfizer Chief Scientific Officer Dr. Mikael Dolsten.
Hospitalizations related to COVID-19 have increased modestly in regions where LB.4 is dominant, though intensive care admissions remain at approximately one-quarter of the levels seen during previous waves.