LAS VEGAS (KLAS) — Twenty-five people who had received a COVID-19 vaccine died in the past two weeks from the virus, new data from the Southern Nevada Health District (SNHD) showed.

The district now reports more than 9,000 breakthrough coronavirus cases in Clark County since vaccines were made available. Out of those 9,080 cases, 137 people died. For the month of September, about one out of every five new COVID-19 cases involves a person who was vaccinated.

“Given the large number of people being vaccinated in the United States and the high level of ongoing SARS-CoV-2 circulation, thousands of symptomatic vaccine breakthrough cases are expected, even if the vaccines remain as effective as demonstrative during clinical trials,” SNHD wrote in its latest report.

In addition to the 25 additional breakthrough deaths, SNHD reported more than 1,400 new breakthrough cases. While there is no pattern in terms of what age those who are vaccinated are then becoming sick, most hospitalized breakthrough cases and deaths involve people 65 and older.

According to SNHD, 73% of all breakthrough hospitalizations involved adults older than 65. In terms of breakthrough deaths, 81% involve the same older population.

The percentage among the vaccinated getting sick has increased steadily since May as the Delta variant spread. So far this month, about 19% of all new cases involve the vaccinated.

This percentage has trended upwards since June when about 12% of cases involved the vaccinated. The percentage was about 16% in July and 18% in August.

According to the CDC, unvaccinated people are five times more likely to be infected with COVID-19 than the vaccinated. The unvaccinated are 29 times more likely to be hospitalized with COVID-19 than the vaccinated, the CDC reported earlier this month.

The vaccines were developed to prevent earlier coronavirus strains, meaning the Delta variant, which is the predominant strain circulating in the United States, was not around yet.

Nearly 1.4 million people in Clark County have received at least one dose of a COVID-19 vaccine, SNHD reported Monday. About 1.14 million residents have received have completed the vaccination process.

SNHD did not release a breakthrough case report due to “technical difficulties,” it said.

Your chances of dying after getting at least one dose of the COVID vaccine are about 1 in 10,000.