After a more than 16-month battle against COVID-19, Dallas County has reached herd immunity, according to a July 7 statement from the Parkland Center of Clinical Innovation.

The county achieved the 80% herd immunity threshold July 4, according to the statement. That percentage includes 46.6% of the total population that is vaccinated and the remaining 48.7% that has natural immunity from a previous COVID-19 infection.

“While this represents good progress, it is important that we understand the work is not over,” PCCI CEO Steve Miff said in the statement. “We must continue to push for vaccinations so COVID and its variants can’t again take hold and diminish the progress we’ve made.”

According to The Mayo Clinic, herd immunity occurs when a large portion of a community becomes immune to a disease, which makes the spread of the infection from person to person unlikely. This results in widespread protection for all members of the community, including those who are not vaccinated.

Since tracking began last spring, there have been a cumulative total of 263,529 confirmed cases of COVID-19 in Dallas County, according to a July 7 news release. A total of 4,139 residents died from the virus, the release stated.

Miff said there are “still significant pockets in the community that remain vulnerable,” noting that 45 ZIP codes have not reached the 80% threshold. Forty-nine of the county’s ZIP codes have reached 80%, while 25 ZIP codes are between 70% and 80% and another 20 ZIP codes are below 70%, according to the statement.

The more infectious Delta variant could cause the herd immunity threshold to increase to 88% as it becomes the dominant strain in a few weeks’ time, Miff said. The variant currently makes up about 25% of COVID-19 cases locally, he added.

The county is still behind on vaccinations, with only 38% of the total population having received both vaccines and 47% having received one dose.

“While previous infections and partial vaccinations do provide a level of protection, all evidence suggests that full vaccinations are the most effective way to stay safe against the delta variant,” Miff said in the statement.

Full approval from the Federal Drug Administration for mRNA vaccines is expected in the upcoming weeks, and approval to vaccinate children under the age of 12 is expected in the fall, Miff said.

“The message is simple: Don’t wait to get vaccinated,” he said. “For those still hesitant, the safety and efficacy studies to date are overwhelmingly positive.”