The more transmissible delta variant of the coronavirus now makes up about 83% of new COVID-19 cases in the U.S., with the majority of deaths occurring in unvaccinated people, the director of the Centers for Disease Control and Prevention said Tuesday.
“This is a dramatic increase up from 50%, the week of July 3,” Dr. Rochelle Walensky said of the current rate of cases involving the delta strain during a Senate hearing. “In some parts of the country, the percentage is even higher.”
Over the last week, the U.S. has averaged 239 deaths per day from the virus. This is a near-48% increase from the prior week. The overwhelming majority of deaths are among those who are unvaccinated, she said.
“Each death is tragic and even more heartbreaking when we know that the majority of these deaths could be prevented with a simple, safe, available vaccine,” she said.
While overall, the number of new COVID-19 cases has declined since vaccines were made available in the U.S. early this year, they have started to rise in recent weeks. Nearly two-thirds of counties still have vaccination rates of less than 40%. Where vaccination rates are low, cases and hospitalizations are starting to climb again, allowing for the delta variant’s spread, she said.
“The message from the CDC remains clear: The best way to prevent the spread of COVID-19 variants is to prevent the spread of disease, and vaccination is the most powerful tool we have,” she said.
Dr. Anthony Fauci, the White House’s chief medical adviser, similarly stressed the need for all Americans to get vaccinated while underscoring the threat that this new variant poses on human health and safety.
“It has the capability of transmitting efficiently from human-to-human in an extraordinary manner, well beyond any of the other variants that we have experienced until now,” he said at the same hearing. “We have the tools to end this epidemic. It is up to us to utilize those tools to their maximum.”
Fauci had warned late last month, when the variant made up an estimated 20% of new cases, that the variant would be the dominant strain in the U.S. in just a matter of weeks. By early July, it made up just over 50% of new cases, according to the CDC.
Fauci said Tuesday that health officials are currently studying whether booster shots are needed for those vaccinated to ensure the durability of the vaccines, but that at this time, more information is needed.
The CDC continues to advise people to wear masks indoors if they are not fully vaccinated against the coronavirus.