受高传播性三角洲变异体和滞后的疫苗接种率的推动，加州、内华达州、密苏里州和阿肯色州的新冠肺炎热点地区正在全国范围内兴起。

为了应对夏季高峰，白宫周四宣布将发出“快速反应小组”帮助全国疫苗接种工作。

疾病控制和预防中心主任罗谢尔·瓦伦斯基周四说，美国约1000个县的疫苗接种覆盖率不到30%，主要集中在东南部和中西部。

内华达州

在内华达州，州长史蒂夫·西索莱克要求联邦政府联邦应急管理局援助作为对一波新冠肺炎案件的回应。该州目前是全国人均周发病率最高的州，每10万居民中有109例疾控中心数据。

内华达州周四报告了543例新病例，大多数来自克拉克县，11例新死亡。该州最近一次报告11人死亡是在4月底，每哥伦比亚广播公司KLAS分公司。

伊森·米勒/盖蒂影像公司，文件

在胡的疫苗接种门诊，人们排队接种疫苗..

根据世卫组织的数据，银州14天的检测阳性率为5.8%，高于世界卫生组织5%的目标，6月份住院人数翻了一番状态数据。

到目前为止，内华达州45%的人口已经开始接种疫苗，38%的人口已经完全接种疫苗。

然而，该州的疫苗接种率在整个6月份稳步下降，从4月中旬的25，000次下降到7天移动平均数5，471次。尽管采取了激励措施，比如该州为接种疫苗者开出了100万美元的大奖彩票，但接种率还是大幅下降。

现在，该州正争先恐后地部署移动疫苗单位，创建新的检测和疫苗接种站点，并加大社区外联和教育力度。

“新冠肺炎疫苗在降低病例、住院和死亡的严重性方面非常有效，我们必须继续利用联邦、州和地方各级的资源来提高可及性和信心，并让尽可能多的内瓦丹人免受这种致命病毒的侵害，”西索拉克在一份声明中说新闻稿周四。

过去两周，一些州的住院人数大幅增加，阿肯色州增加了79.3%，内华达州增加了104%。根据疾病预防控制中心的数据，密苏里州拥有全国最高的住院和重症监护室新冠肺炎入住率，约有700名患者接受护理。

比尔·格林布拉特/合众国际社/Shutterstock

圣路易斯消防队员将老消防队员罗德尼·赫德的灵柩装上游行用的抽水机...

阿肯色州和密苏里州

阿肯色州在大流行期间从未发布过正式的居家命令，周三报告了686例新的可能和确诊的新冠肺炎病例这是四个多月来最大的单日涨幅。

在密苏里州，州长迈克·帕森请求联邦“快速反应小组”帮助处理该州日益增多的新冠肺炎病例。

根据疾病预防控制中心的数据，密苏里州紧随内华达州，人均周发病率位居全国第二，每10万居民中有102例。

根据各州的数据，仅在6月份密苏里州就有超过115，000例新的新冠肺炎病例。这与5月份报告的进展出现了重大逆转，这标志着自2020年6月以来，该州首次在一个月内记录了不到1万例新病例。美国全国广播公司下属的KSHB报道。

马里奥·塔玛/盖蒂影像公司

2021年6月15日，洛杉矶，人们走在好莱坞大道上拍照。

圣路易斯地区

圣路易斯地区的三个县发布了公共卫生公告，引用了新的三角洲变异病例的传播，敦促公众在室内佩戴口罩，即使接种了疫苗。在他们的报告据说，当地卫生部门认为，在任何集会中，三分之一的人可能没有接种疫苗。

在过去的两周内，杰弗逊县的病例增加了42%，其中10至19岁年龄组的病例最多。

“这是令人担忧的，因为大多数年龄组的人都有资格接种疫苗，但只有10.82%的人完成了全部系列的疫苗接种，”该县在一份声明中说报告。

到目前为止，39.1%的州人口已经完成了疫苗系列，44.5%的人已经开始接种疫苗状态数据。

类似的新冠肺炎骚乱正在加州洛杉机县酝酿。

达米安·多瓦甘内斯/美联社，档案

在新冠肺炎街头，顾客们戴着口罩在一个停业的户外商场里..

洛杉矶县

该县周四报告了506例新病例，这是自4月中旬以来的最高日病例数。据报道，这一数字是6月15日报道的两倍多，当时该州和县解除了对新冠肺炎的限制郡的冠状病毒跟踪器。

卫生官员周四表示，从上周到本周，测序的δ变体数量翻了一番，达到245例，占所有报告序列的47%。到目前为止，在洛杉矶县16岁及以上的居民中，59%的人已经完全接种了疫苗县数据。

县公共卫生主任芭芭拉·费勒博士在周四的新闻发布会上说，新冠肺炎感染和死亡人数的上升越来越影响有色人种社区，那里的疫苗接种率仍然是最低的。

她还说，18岁至49岁的当地人对此感到担忧，尽管接种疫苗在这些人群中增长缓慢。

该县还推出了自己的激励措施:向接种疫苗的成年人提供六旗游乐园、动物园和博物馆的门票。

美国广播公司新闻撰稿人、哈佛医学院教授、流行病学家约翰·布朗斯坦说，今天有热点并不奇怪。

“并非每个社区都开展得很好。他说:“当接种疫苗不足的人群与可能没有经历过激增的人群混合在一起时，如果没有疫苗诱导免疫和自然免疫的结合，病例将会增加。”“因为我们有最易传播的变异体，即delta变异体，所以我们会看到病例增加也就不足为奇了。”

布朗斯坦指出，激增的原因包括缺乏疫苗和疫苗信心，以及年轻人接种率低。

“一方面，这些人群可能看不到疫苗的价值，因为他们可能认为自己是不可战胜的，或者可能没有被感染的风险，”他说。“还有一个挑战是确保父母同意为他们的孩子接种疫苗——你有同意的问题。”

Here are the summer hotspots in the US where COVID-19 is resurging

COVID-19 hotspots are emerging across the country, fueled by the highly transmissible delta variant and lagging vaccination rates, in California, Nevada, Missouri and Arkansas.

To combat summer spikes, the White House announced Thursday it will send out"surge response teams"to aid in nationwide vaccination efforts.

About 1,000 counties in the U.S. have vaccination coverage of less than 30%, and they're concentrated primarily in the Southeast and Midwest, Centers for Disease Control and Prevention Director Rochelle Walensky said Thursday.

Nevada

In Nevada, Gov. Steve Sisolak asked the federal government forFederal Emergency Management Agency assistancein response to a wave of COVID-19 cases. The state currently has the highest weekly case rates per capita in the country, with 109 cases per 100,000 residents, according toCDC data.

Nevada reported 543 new cases, most from Clark County, and 11 new deaths on Thursday. The last time the state reported 11 deaths was near the end of April, perCBS affiliate KLAS.

The Silver State has a 14-day test positivity rate of 5.8%, which is above the World Health Organization's goal of 5%, and hospitalizations have doubled in the month of June, according tostate data.

So far, 45% of Nevada's population has initiated vaccination and 38% of the population is fully vaccinated.

However, the state's vaccination rate has steadily decreased throughout June to a 7-day moving average of 5,471 shots being administered, a drop from 25,000 administered in mid-April. The plunging rate comes in spite of incentive efforts like the state's $1 million grand prize lottery for the vaccinated.

Now the state is scrambling to deploy mobile vaccine units, create new testing and vaccination sites, and increase community outreach and education efforts.

"The COVID-19vaccinesare highly effective at reducing the severity of cases, hospitalization and deaths and we must continue to leverage resources at the federal, state and local level to increase access and confidence and get as many Nevadans protected from this deadly virus as possible,"Sisolaksaid in apress releaseThursday.

Hospital admissions have increased significantly over the last two weeks in some states, up 79.3% in Arkansas and 104% in Nevada. Missouri has the country's highest rates of inpatient and intensive care unit COVID-19 occupancy, with approximately 700 patients receiving care, according to the CDC.

Arkansas and Missouri

Arkansas, which never issued an official stay-at-home order during the pandemic, reported 686 new probable and confirmed COVID-19 cases Wednesday --the largest one-day increase in more than four months.

In Missouri, Gov. Mike Parson has asked for help from federal "surge response teams" to deal with the mounting number of COVID-19 cases in the state.

Missouri follows Nevada with the second-highest weekly case rates per capita in the country, at 102 cases per 100,000 residents, per the CDC.

There were more than 115,000 new COVID-19 cases in Missouri in June alone, per state data. It's a major reversal of the progress reported in May, which marked the first time the state recorded less than 10,000 new cases in a month since June 2020,NBC affiliate KSHB reported.

St. Louis area

Three counties in the St. Louis region have issued public health advisories, citing the spread of new delta variant cases, urging the public to wear masks indoors, even if vaccinated. In theiradvisory, local health departments said to assume one in three people in any gathering may be unvaccinated.

Over the last two weeks, cases in Jefferson County increased 42%, with the highest number of cases in the 10- to 19-year-old age group.

"This is concerning since most of that age group is eligible for the vaccine, but only 10.82% have completed the full series of vaccination," the county said in anadvisory.

So far, 39.1% of the state population has completed the vaccine series and 44.5% have initiated vaccination, perstate data.

Similar COVID-19 turmoil is brewing in Los Angeles County, California.

Los Angeles County

The county reported 506 new cases on Thursday -- the highest daily number since mid-April. That's more than double the number reported on June 15, when the state and county lifted COVID-19 restrictions, according to thecounty'scoronavirustracker.

Between last week and this week the number of delta variants sequenced doubled to a total of 245 cases -- 47% of all sequences reported, health officials said Thursday. So far, among LA County residents 16 and up, 59% are fully vaccinated, according tocounty data.

County Public Health Director Dr. Barbara Ferrer said in a press conference Thursday the rise in COVID-19 infections and deaths is increasingly affecting communities of color, where vaccination rates remain the lowest.

She also said there's concern among locals between 18 to 49, though vaccination is increasing slowly among that demographic.

The county has also rolled out its own incentives: offering tickets to Six Flags, the zoo and museums to vaccinated adults.

ABC News contributor John Brownstein, an epidemiologist and professor at Harvard Medical School, said it's no surprise there are hotspots today.

"The rollout has not gone as well in every community. When you have under-vaccinated populations mixed with those who have maybe not experienced surges, you don't have a combination of both vaccine-induced immunity and natural immunity, you're going to see cases increase," he said. "And because we have the most transmissible variant, the delta variant, it's not unexpected that we'll see increases in cases."

Brownstein noted reasons for the surges include a lack of access to vaccine and vaccine confidence and the low vaccination rates among the young.

"On one hand those populations may not see the value of vaccine because they may think that they're invincible or may not have a perceived risk of infection," he said. "There's also the challenge of making sure the parents are on board with vaccinating their kids -- you have the consent issue."