SAN FRANCISCO (KPIX) — On Monday, California reported more than 14,097 new cases from over the weekend, which is triple the number of cases reported in early June.

The test positivity rate also spiked to 4.1%, which is the highest it’s been since February. Last month, the state’s positivity rate was below 1%.

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As cases climb, however, vaccination has stalled and experts worry about what that means for the future of the pandemic.

“The more that transmission of virus occurs, the more likely there is going to be another mutation,” said University of California San Francisco Prof. of Medicine and Infectious Disease Specialist Dr. Peter Chin-Hong. “In fact, we know from science every two weeks there is a new mutation.”

In California, nearly 52% of the population is fully vaccinated, which means millions remain unvaccinated.

Experts have said the unvaccinated as well as the highly-transmissible Delta variant are currently driving the pandemic.

Last month, the Delta variant was behind 43% of the COVID-19 cases analyzed in the state.

Dr. Chin-Hong worries a stronger, more vaccine-resistant variant could surface if more people don’t get inoculated.

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“If you don’t break the chain of transmission you’re going to get the creation of new variants so this is a tale that’s going to be told over and over again,” Chin-Hong said. ”

It’s going to be Groundhog Day. The same scenes get replayed over and over again. But the uplifting, silver lining is still we have time to do something about it, because right now all the variants we know are susceptible to the vaccines.”

Dana Moll who is visiting the Bay Area from Missouri, however, said she refuses to get the vaccine.

“There’s no way that I would choose to get that vaccination,” said Moll. “They can’t convince me that within less than a year that they’ve done a lot of research. I’ve also chosen for my kids not to get it as well.”

Some who are unvaccinated, including James McGettigan, said they’re not necessarily against the vaccine, but feel it would put them at risk for future health issues.

“One of the last times I was vaccinated I was young, around 6-years-old,” McGettigan said. “A couple weeks later I got seizures that lasted like about five years. I’m not saying not everybody shouldn’t get the vaccine, but me personally, I know what that led to.”

Moll said no matter what experts say it’s not enough to convince her to get a shot in the arm.

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“I don’t feel pressured by it,” said Moll. “I’m making up my own decisions based on my own thoughts and my own research.”