The number of COVID-19 cases in Nebraska fell 7% last week, ending a nine-week stretch of rising case numbers.

The state recorded 2,998 new virus cases for the week ending Friday, compared to 3,240 the week before, according to figures from the federal Centers for Disease Control and Prevention.

Cases fell in more than two-thirds of the states and were down 12% nationally.

Nebraska’s case levels also remain relatively low for the nation, about 20% below the U.S. rate.

Cases continue to explode in neighboring Wyoming, which last week had both the nation’s highest case growth and highest case rate.

Iowa is among the states that saw increasing cases, though its per-capita case rate remains among the lowest in the country.

Meanwhile, some who have long avoided the virus recently have tested positive. Nebraska Gov. Pete Ricketts and first lady Susanne Shore tested positive for COVID last week and reportedly were experiencing mild symptoms. Ricketts has been vaccinated and received a booster shot, according to his spokeswoman.

Dr. Anthony Fauci, the leader of the U.S. government’s COVID pandemic response effort, also tested positive for the coronavirus last week. Fauci, 81, has been vaccinated and twice boosted and likewise was reporting mild symptoms.

Dr. James Lawler, an executive director of the University of Nebraska Medical Center’s Global Center for Health Security, said there likely are a number of reasons that the virus is catching people who so far have avoided it.

One obvious reason, he said, is that there is more of the virus circulating than is being picked up on officially reported tests.

Many people infected with COVID aren’t getting tested for it, and many of those who do test are using at-home antigen tests that aren’t routinely reported or included in official counts.

“We have a much cloudier view into what’s really happening in overall community numbers,” Lawler said. “It’s probably true that infection rates in communities are quite a bit higher than what the official numbers would lead you to believe.”

In addition, he said, the versions of the virus now circulating — BA.2.12.1, which last week made up an estimated 64% of reported cases nationally, and the newer BA.4 and BA.5 — are much more transmissible than previous strains. That goes for the original Wuhan strain and even the BA.1 version of omicron.

In addition, many people now are months out from their last dose of vaccine or their last booster. “We know with these vaccines,” Lawler said, “immunity wanes over time, especially with some of these newer variants.”

Immunity induced by COVID-19 infections also wanes over time, he said. Some people who contracted the delta or BA.1 strains now are getting the newer strains.

During the week ending June 6, the Douglas County Health Department reported 772 initial COVID infections and 126 reinfections. Those are defined as a second positive test more than 90 days after a prior positive test at any time after Sept. 1. The Health Department has tallied a total of 5,816 reinfections among county residents.

At the same time, the vaccines continue to provide significant protection against serious illness and death. In December, state health officials reported that Nebraskans who were fully vaccinated but not boosted were 11 times less likely than those who had not been vaccinated to require hospital care. Those who had been vaccinated and boosted were 46 times less likely to be hospitalized than those who hadn’t gotten any shots.

In Douglas County, some 39,017, or 10.3%, of fully vaccinated residents ages 5 and older had reported a breakthrough infection as of June 6. The percentage who died of COVID-19 was .045%.

Additionally, Lawler said, people are taking fewer precautions against the virus than they were six months or a year ago. Fewer people are masking indoors. In such spaces, even a masked person has a greater risk of catching COVID.

Nebraska COVID-19 hospitalizations also were down slightly last week, with a daily average of 124 hospitalized patients, down from 129 the previous week.

Nebraska recorded seven new COVID deaths, bringing the toll of confirmed or probable deaths for the pandemic to 4,330. Total reported cases are inching close to half a million, topping 494,000.