A map shows the 12 states most at risk from COVID-19, all with high levels of Delta and below-average vaccination rates

• The 12 US states at most risk from COVID-19 include Arkansas, Nevada, and Missouri, according to Covid Act Now.
• The organization uses CDC data and is partnered with Stanford, Harvard and Georgetown Universities.
• The highest risk states include those with lower vaccination rates and more cases of the highly infectious Delta variant.

The US states most at risk from COVID-19 include those with below-average vaccination rates and high levels of the infectious Delta variant, according to data from an influential non-profit that's partnered with Stanford, Harvard and Georgetown Universities.

Twelve states including Arkansas, Nevada, and Missouri are now at "high risk" from COVID-19, according to Covid Act Now's US COVID risk and vaccine tracker, which mostly uses Centers for Disease Control and Prevention (CDC) data. There are just two states at low risk from COVID-19 - Massachusetts and Vermont.

The 12 states at high risk from COVID-19, according to Covid Act Now, are: Nevada, Utah, Missouri, Wyoming, Nebraska, Kansas, Oklahoma, Arkansas, Mississippi, Louisiana, Florida, and South Carolina.

Covid Act Now's risk calculations are based on six factors that include infection rates, the percentage of people vaccinated, capacity at intensive care units, and socio-economic vulnerabilities that may impact recovery. There are five levels of risk: severe risk, very-high risk, high risk, medium risk and low risk.

Professor Eric Topol, director at the Scripps Research Translational Institute, said on Twitter on Friday that states had moved up risk categories as the Delta variant continued to spread, citing Covid Act Now. He said Delta accounted for at least 35% of new cases in these high-risk states.

Thirty-six states are at medium risk, while two - Massachusetts and Vermont - are low risk, according to Covid Act Now's data. Both of these states have low levels of Delta variant, according to Scripps Research's Outbreak.info.

More than 80% of people are fully vaccinated in both states, according to data from Johns Hopkins University - well above the nation's 47% average.

By comparison, the Delta variant accounts for more than 80% of new cases in Arkansas, Nevada, and Missouri, according to Outbreak.info. The number of people fully vaccinated is 34% in Arkansas, 42% in Nevada, and 39% in Missouri.

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Actual figures may vary because there can be delays in uploading data, or it may not be available. Insider's Aria Bendix reported on Friday that the CDC stopped monitoring non-severe COVID-19 cases among vaccinated people in May. The number of tests sequenced also differs. For example, the data from Massachusetts is based on more than 18,000 sequenced tests, and Arkansas' data comes from just over 960 sequenced tests, according to Outbreak.info.

It's not clear how the level of risk will translate to new infections.

Topol said it was promising that the number of new daily cases was still low. "But rising," he added.