(CNN) � Health officials are concerned about the number of coronavirus cases in states with low vaccine rates.
The Center for Disease Control and Prevention released  looking at states with vaccination numbers lower than the overall U.S. rate.
More than 47% of Americans are fully vaccinated in the U.S., according to the data.
Researchers say states with fewer residents vaccinated are seeing infection rates three times higher on average.
Ten states saw cases increase more than 25 percent over the past seven days compared to the weeks before.
Nine of those states have a smaller share of vaccinated residents than the U.S. overall.
