By Stephanie Stahl

PHILADELPHIA (CBS) — New milestones on the road to recovery — the lowest number of daily COVID deaths since the pandemic started, and 150 million Americans are fully vaccinated. But there are growing concerns about the delta variant that has been detected in our tri-state region.

The delta variant that started in India is spreading and is now expected to become a dominant strain of the virus in the United States.

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A new study says 25% of COVID patients have symptoms that last a month or more.

COVID-19 cases continue to decline but there are growing concerns about the delta variant that now accounts for nearly 10% of cases. In April, it was just over 1%.

“Children and young people seem to be the ones spreading the delta variant,” New Jersey Health Commissioner Dr. Judy Persichilli said.

The strain is now being called a variant of concern because it’s more transmissible, can cause more severe disease, and vaccination treatments and tests may be slightly less effective.

“The delta variant is out-competing the other variants, which means more transmissible. It’s becoming an increasing percentage in New Jersey and other places,” New Jersey Health Director Dr. Ed Lifshitz said.

New Jersey health officials say the variant has not caused an increase in hospitalizations. They credit more people being vaccinated.

“There’s a direct correlation between our increasing vaccination rates and our decreasing infection and hospital numbers,” Gov. Phil Murphy said.

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Murphy expects the state to reach a vaccination rate of 70% before the end of the month.

Nationwide, 53% of the country has received at least one dose, far short of the president’s goal.

“We’re going to continue to push vaccination beyond the 4th of July, into the summer,” Dr. Anthony Fauci said.

A new study shows nearly 25% of COVID-19 patients had symptoms lasting 30 days or more, pain and breathing difficulties being most prominent.

“This can affect any and everyone, which is a big part of the reason why we are pushing these vaccines,” emergency medicine physician Dr. Richina Bicette said.

Currently, 150 million Americans are fully vaccinated.

“Instead of heading into a summer like last summer of isolation, uncertainty, and loss, we’re headed into a summer of joy, celebration and increasing freedom from the virus,” said White House COVID-19 Response Coordinator Jeff Zients.

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Officials say almost all of the new cases of COVID-19 are among people who are not vaccinated.

Stephanie Stahl