Updated May 8, 2021 - 9:00 am
Dozens of Nevadans fully vaccinated against COVID-19 have been hospitalized after contracting rare breakthrough cases of the disease, state health officials reported in new data released Friday.
The majority of the 51 cases were white, male, and age 70 and older, among those most at risk of severe infections. But 32 of the patients showed no symptoms of COVID-19 infection, according to the Nevada Department of Health and Human Services data.
Nearly all of the cases were in Clark County, where local health officials had reported at least two deaths among 186 breakthrough cases as of Thursday.
However, UNLV epidemiologist Brian Labus said there is no need for alarm about the relatively small number of breakthrough cases resulting in severe outcomes. More than 880,000 people have been fully vaccinated statewide, and in Clark County, the cases account for only about 0.03 percent of the more than 630,000 residents fully vaccinated.
“This is something rare enough that it didn’t show up until we vaccinated over half a million people,” he said. “We don’t want any deaths to occur, but we’ve had over 4,000 deaths (in Clark County) from COVID during the pandemic.”
Health officials had expected virus transmission would still occur among vaccinated people because none of the three vaccines — Moderna, Pfizer and Johnson &Johnson — claim to completely stop disease transmission. Instead, they prevent severe illness, hospitalization and death at least 97 percent of the time, state officials said. Their effectiveness in preventing infection ranges from 70 to 95 percent.
While initial clinical trials for the vaccines found that COVID-19 did not hospitalize or kill anyone who was fully immunized, Labus said the vaccines’ effectiveness are now being tested at a much larger scale.
“If you have something that occurs in one of every 100,000 people, it may not have shown up in the clinical trial,” he said.
Nevada and the Centers for Disease Control and Prevention define a breakthrough case as a person testing positive for COVID-19 two or more weeks after a final vaccine dose.
The Review-Journal asked the Southern Nevada Health District for specifics about age, underlying conditions and vaccines administered for the breakthrough case patients in Clark County who died.
Agency spokeswoman Stephanie Bethel declined to provide the information, stating it would “compromise patient confidentiality.” She wrote that federal officials were investigating the deaths.
“The Centers for Disease Control and Prevention has advised that COVID-19 vaccines are highly effective; however, because they are not 100 percent effective, breakthrough cases are expected, including some that could result in hospitalizations or death,” she wrote.
Nevada’s Department of Health and Human Services is analyzing breakthrough cases statewide for patterns or trends.
On Friday, the agency for the first time released demographic data on 51 breakthrough cases who had been hospitalized or died. The data did not delineate between the two outcomes.
The data showed that 36 of those with severe outcomes were age 70 and older. The youngest were four people in their 30s.
Most of the people were white and male, according to the data. All but four lived in Clark County.
The Nevada State Public Health Laboratory is determining how many breakthrough cases have been caused by COVID-19 variants. State officials have yet to publish that data.
Lab director Mark Pandori said Friday his team has analyzed about 60 specimens. Of those, about half had a high enough viral load for genomic sequencing, he said.
“There’s no particular lineage that stands out in regard to breakthrough,” he said. “It certainly appears that the vaccines are working, even in the face of the fact that the variant of concerns are circulating at high levels.”
In Clark County, health district data shows only two breakthrough cases linked to variants. One patient had contracted B.1.1.7 out of the U.K., and another had contracted P.1, first identified in Brazil.
Nationally, there had been 9,245 breakthrough cases reported to the Centers for Disease Control and Prevention as of April 26. Among those people, 835 had been hospitalized and 132 had died, according to CDC data. Not all were tied to their COVID-19 infection.
Editor’s Note: This story was updated May 6 with newly-published Southern Nevada Health District data on breakthrough cases. The story was updated May 7 with newly-published Nevada Department of Health and Human Services data on breakthrough cases.