The omicron subvariant BA.5 is now the dominant strain of COVID-19 in the U.S.
According to the Centers for Disease Control (CDC), BA.5 now makes up more than 50% of new cases in the country.
Health officials have said the BA.5 subvariant is more contagious and can more easily evade vaccine protection. However, medical professionals don't believe it causes more severe illness.
The World Health Organization (WHO) said last week that 110 countries are experiencing a rise in COVID infections due to the BA.4 and BA.5 subvariants.
The two subvariants are responsible for about 70% of all new infections in the U.S.
The WHO says second-generation vaccines are needed to prevent more unnecessary illness and death.
Moderna says it has developed an updated vaccine that targets the omicron variant, which could be available as early as the fall.