As vaccination rates increase and the rate of new COVID-19 cases decreases across California, the state has moved forward with sweeping reopening plans — impeded, however, by the rise in cases of the virus’s highly contagious delta variant.

Since early June, the United States has seen a sharp rise in the percentage of cases caused by the delta variant, a mutation of the virus that was originally identified in India in December 2020, according to the Centers for Disease Control and Prevention.

The variant is now widespread across more than 90 countries, and California reached 1,085 variant cases as of July 7, according to the California Department of Public Health, or CDPH. CDPH data showed that the delta variant has made up more than 40% of COVID-19 cases in the past month, making it the dominant strain in the state.

The delta variant is among four strains classified as variants of concern by the CDC and has been responsible for a number of COVID-19 outbreaks across the United States. It has not yet been classified by the CDC as a variant of high consequence though, meaning it won’t considerably decrease vaccine effectiveness or significantly increase the severity of the disease, the CDC website reads. 

The main concern of the variant is its high transmissibility, which could potentially increase the strain on health care resources and pose a greater threat to unvaccinated members of the community, according to the CDC.

Though the CDC has emphasized the protective efficacy of currently approved vaccines against variants, Pfizer announced its hopes of developing a third booster shot, specifically targeting the delta variant. The CDC and U.S. Food and Drug Administration released a joint statement in contradiction, stating that “Americans who have been fully vaccinated do not need a booster shot at this time.” 

University Health Services, or UHS, spokesperson Tami Cate stressed the importance of vaccination in the community to prevent the spread and emergence of variants. To ensure this, the university implemented a vaccine mandate for students and staff during the fall semester, and UC Berkeley continues to provide free campus COVID-19 vaccination clinics, Cate added.

“Variants will continue to emerge, particularly with low overall global vaccination; the best tool we have continues to be vaccination,” Cate said in an email. “We have had and will continue to have a robust campus COVID response plan.”

Due to the increased transmissibility of the delta variant, UHS and campus have continued to encourage mask use indoors for unvaccinated people, according to Cate. Regular COVID-19 testing of unvaccinated students and staff has been administered, as well as periodic surveillance testing of vaccinated people to monitor case trends.

Cate noted that UC Berkeley performs wastewater testing and additional sequencing on any positive tests collected to detect variants.

“UHS and campus are keeping a keen eye on variants – both global and local patterns and will adjust our campus public health guidelines as needed, working closely with the Public Health Department,” Cate said in the email.