By Erika Edwards - NBC News
The number of COVID-19 cases in the United States increased 10% this week as a result of the
spread of the
highly contagious
delta variant
, the Centers for Disease Control and Prevention (CDC, for its acronym in English).
Rochelle Walensky, director of the CDC, explained during a briefing at the White House that the increase could be due to a combination of factors: the
low vaccination rate in
the country and the "hypertransmissible delta variant."
[Ghana uses drones to distribute COVID-19 vaccine]
This new strain, which was first detected in India, already accounts for a quarter of all new cases and has been detected in all 50 states.
Its rapid spread is sure to make it the dominant variant in the United States in the coming weeks, the expert said.
An average of 12,600 cases
were detected
a day
in the past week, 10% more than last week, Walensky said.
Although this number is nowhere near the peak recorded in January with more than 247,000 daily cases of COVID-19, this rebound makes
some experts
"
a little nervous.
"
"I don't want the trend to put us in a position where it really [the number of infections] can take off," especially as fall approaches and people congregate indoors again, said Cameron Wolfe, an infectious disease specialist and Professor at Duke University School of Medicine.
Los Angeles calls again for the use of a mask in the face of the delta variant of COVID-19
June 30, 202103: 22
"I predict that
we will see the number of cases increase
across the country as the delta variant spreads," said Richard Besser, president of the Robert Wood Johnson Foundation and former acting director of the CDC.
"The reason [this will happen] is that a significant number of people in the United States are not yet vaccinated," he stressed.
"It is clear that the communities where people remain unvaccinated are communities that remain vulnerable," Walensky said.
As of Thursday, 57% of adults were fully vaccinated, according to the CDC.
For now, the increase in COVID-19 cases does not appear to translate into an increased severity of the disease, at least nationally.
The average of seven days of
hospitalizations
for the virus across the country has decreased by approximately 1% compared to last week, said the expert.
[Vaccines against COVID-19 do protect against the infectious delta variant, although the effectiveness is lower]
Foci of unvaccinated communities in the Southeast and Midwest remain the most vulnerable.
"As the delta variant continues to spread across the country, we expect to see increased transmission in these communities unless we can vaccinate more people now," Walensky said.
The Joe Biden administration has pushed for 70% of adults to receive at least one dose by July 4, but acknowledged last week that it will not reach that goal. As of Thursday,
66.5% of the adult population had received at least one dose
.