Breakthrough COVID cases in Nevada: What we know

The number of Nevadans fully vaccinated against COVID-19 that later tested positive for the disease has almost doubled.

State health officials reported knowing of 96 rare “breakthrough cases” as of Thursday afternoon. About a week ago, the state’s Department of Health and Human Services had reported 58 such cases.

Of the breakthrough cases, 51 have been identified in Clark County residents and 32 in Washoe County residents. Other than their county of residence, no other information has been released about those infected.

The department’s Office of Public Health Investigations is analyzing the cases.

More than 650,000 Nevada residents have been fully vaccinated against the deadly respiratory disease as of Wednesday, the department reported.

Editor’s Note: Below is previous reporting first published on April 7.

Dozens of Nevadans who are fully vaccinated against COVID-19 have tested positive for the disease, something state health officials had anticipated.

Of the 58 cases, it is not publicly known how ill people with the rare “breakthrough cases” have become, or which novel coronavirus strain they have. Health officials did not disclose which vaccines had been administered in those cases, but they said most had occurred in Clark County.

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.

What is clear is that the cases represent a minuscule fraction of the more than half-million vaccinations completed in Nevada, according to data from the state’s Department of Health and Human Services.

“At this time, these breakthrough cases are below what the Department statistically expected to see based on the initial data available on vaccine efficacy,” department spokeswoman Shannon Litz wrote in an email.

The department’s Office of Public Health Investigations is analyzing the cases, Litz added.

None of the three COVID-19 vaccines available to Nevadans — Pfizer, Moderna and Johnson & Johnson — claim to completely stop disease transmission.

Instead, they prevent severe illness, hospitalization and death at least 97 percent of the time, Litz said. Their effectiveness in preventing infection ranges from 70 to 95 percent.

While they aren’t perfect, the vaccines offer the best protection we have against COVID-19, said Dr. Mark Riddle, a professor of internal medicine at the University of Nevada, Reno. They should also be paired with other preventative measures, like washing your hands and wearing a face mask, while COVID-19 is still circulating in our communities.

“We can’t predict that you’re going to have a bad outcome or a not-bad outcome,” Riddle said. “Given that unpredictability right now, you need to err on the side of caution.”

Riddle said the breakthrough cases should be examined for similarities that could help explain why they are occurring. There could be common threads, such as if most of those infected received the same vaccine, tested positive for the same COVID-19 variant or had the same underlying health conditions.

“The importance of really studying these breakthrough cases is trying to understand certain subpopulations of patients who may not respond as well to the vaccine,” he said. “If all these breakthrough cases are mainly variants, then that would kind of support this need to boost vaccination with updated vaccines.”

So far, Nevada health officials don’t have specifics available for the public.

“(The state) is working with Nevada’s Local Health Authorities, the Nevada State Public Health Laboratory and the Centers for Disease Control and Prevention to enhance the reporting and support the analysis of these cases,” Litz wrote in an email. “As with other metrics related to COVID-19 disease investigation and contact tracing, this information is self-reported by the individual.”

Breakthrough cases are appearing in other states. News reports this week show at least 246 fully vaccinated Michigan residents were diagnosed with the virus — 11 were hospitalized and three died. In South Carolina, more than 140 breakthrough cases have been reported, and in Utah, health officials confirmed there were 97 cases among the 521,000 fully vaccinated Utahns. As of March 30, Washington state health officials had reported 102 cases, and 97 were reported in Idaho.

Information on vaccination sites can be found at NVCovidFighter.org. For assistance making an appointment, call 800-401-0946.

Contact Michael Scott Davidson at sdavidson@reviewjournal.com or 702-477-3861. Follow @davidsonlvrj on Twitter.