SALT LAKE CITY — Utah’s COVID-19 statistics continued heading in the right direction Tuesday with just 591 new cases and one additional death reported.

But health experts warn now is not the time to ease up against the deadly virus.

Dr. Brandon Webb, an Intermountain Healthcare infectious diseases physician, said Tuesday that while “a rough estimate” suggests around 20% of Utahns may have immunity against COVID-19, either through contracting the virus or getting vaccinated, it’s important that everyone continue wearing masks and taking other precautions.

The recent decline in case counts “means the state is doing the right things and the community is pulling together,” Webb said.

Still, he said Utah’s seven-day rolling average for coronavirus cases is now about the same level it was in October, “when we really started to see the fall/winter surge. A thousand per day is still too high.”

With the new case counts reported by the Utah Department of Health Tuesday, the rolling seven-day average for positive tests is 950 per day. The number of Utahns tested for COVID-19 increased by 4,015 since Monday, while the number of tests conducted went up 9,985.

That puts the rolling seven-day average for percent positivity of tests at 13.7%, when repeat tests given to an individual over a 90-day period are excluded. The rolling seven-day average for percent positivity when all tests are included, the measure state officials recently adopted, is 6.42%.

There are still 272 people hospitalized with COVID-19 in Utah. A total of 1,797 Utahns have died from the virus to date, including the latest loss of life in the pandemic, a Salt Lake County man older than 85 who was hospitalized at the time of death.

‘Race between vaccines and variants’

Also, Utah now has confirmed 12 cases of the so-called U.K. variant of the coronavirus, believed to be not only more contagious but also possibly more deadly. As of Sunday, the Centers for Disease Control and Prevention reported there’s been 1,173 cases of the variant in 40 states, including 379 in Florida and 186 in California.

Webb told reporters during a virtual news conference Tuesday that Utah “can’t go fast enough” when it comes to vaccinating residents. “That’s the bottom line here. We’re actually in a situation where we’re in a race between vaccines and variants.”

He said the sooner Utahns can get vaccinated, the greater the chances of limiting the spread of the variant that first surfaced in Britain last fall and by the end of the year, dominated that nation’s caseloads, as well as of other variants from South Africa and Brazil that are starting to show up in the United States.

Cases of those additional variants haven’t yet been detected in Utah, although the Brazilian variant has been seen in Minnesota and Oklahoma, and the South African variant in California, Texas, Illinois, Maryland, Virginia, North Carolina and South Carolina.

New contact tracing app

The state health department announced a new contact tracing system will be launched Wednesday that lets Utahns choose to receive and share notifications about possible exposures to COVID-19. Three alerts will be sent out over smartphones during the next week to encourage Utahns to turn on the new system, the department said.

The Google/Apple “Exposure Notification Express” system “uses encrypted or anonymous tokens exchanged through your phone and the phones of those around you to keep an encrypted log of who you’ve been in contact with,” said Navina Forsythe, director of the state health department’s Center for Health Data and Informatics.

Forsythe said the system does not track the user’s location. People who test positive for COVID-19 can enter the verification code given to them by the health department to anonymously alert others using the system who came into close contact with them about possibly being exposed.

“The success of exposure notification is dependent on how many people opt in to the service,” Forsythe said, noting modeling has estimated that if only 15% of Utahns use the system, that could result in up to a 15% reduction in infections and 11% fewer deaths.

The new contact tracing app is a free service from Google and Apple, state health department spokesman Tom Hudachko said. Last year, state auditors criticized a $6.3 million contract to develop the “Healthy Together” app, initially intended to be a contact tracing tool.

Immunity starting to increase in Utah

The drop in Utah’s coronavirus cases is a result of many following public health guidelines intended to slow the spread of the deadly virus including social distancing and avoiding large gatherings, the doctor said, along with getting vaccinated.

As of Tuesday, the state reported an increase of 7,952 vaccine doses have been administered, for a new total of 532,985 doses.

State officials hope that by the end of May, every adult in Utah who wants to be vaccinated will have had the opportunity to get the shots. A statewide mass vaccination effort, including a call for volunteers, is gearing up to begin March 1 to take advantage of more doses being allotted by the federal government.

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The state’s health care workers, first responders, long-term care facility residents and staffs, K-12 teachers and school staffs, and residents who are 70 and older are already eligible for the vaccine. Starting March 1, those 65 and older as well Utahns of all ages with specified chronic medical conditions will be added to the list.

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Add the number of Utahns vaccinated against COVID-19 to the nearly 180,000 who have had the virus in the past three months, and Webb said the state is “now starting, little by little, to see some population immunity. Now, we’re probably somewhere just under 20% at this point. That’s a rough estimate and it’s not enough. But it is helping.”

Last week, state epidemiologist Dr. Angela Dunn said Utah will need to have 70% to 80% of residents vaccinated before changes can be considered to the public health measures in place, such as mask wearing, that apply even to those who’ve been vaccinated.

“We’ll start to see what our policies should look like then. But for the next several months, continue mask wearing and physical distancing regardless of whether you’ve had your vaccine yet or not,” she said, noting it is still not clear whether the vaccines keep someone from transmitting the virus to others.

The first of the required two doses of the vaccines currently approved for use in the United States still leaves people vulnerable to the virus, too.

“We are seeing too many cases of acute COVID in people who have received their first dose. What we know from the data so far is that you’re not fully immune until you’ve had the full two-dose series,” Webb said. “You have very little immunity for the first two weeks after receiving the first dose.”