Utah's COVID-19 vaccination numbers are picking up speed; new positivity rate formula explained

Kelsey Merlo, a pharmacy intern and a University of Utah pharmacy student, prepares a COVID-19 vaccination for  Laurence A. Morgan at the Fourth Street Clinic in Salt Lake City  on Tuesday, Jan. 26, 2021. The Salt Lake County Health Department allocated 80 doses of the vaccine to the clinic, which serves many people experiencing homelessness.

(Scott G Winterton, Deseret News, File)

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SALT LAKE CITY — Utah's vaccination efforts have grown significantly over the past few weeks.

The state reached a seven-day running average of a little over 12,500 vaccinations per day on Feb. 1 compared to 5,250 on Jan. 1, Utah Department of Health data shows. Although some of that is second-dose vaccinations, it still shows the vaccinating process is speeding up after a slow start.

The state reported on Feb. 4 that it only had 2,184 doses that hadn't been used after seven days — a large drop from 26,399 on Jan. 24. That also indicates that the state's supply is going straight into the arms of Utahns.

Gov. Spencer Cox also provided an update on incoming vaccine supplies last week. He said it's entirely possible that Utah will begin to receive over 100,000 first-round vaccine doses per week by the end of winter. That increase would be the result of Pfizer-BioNTech and Moderna boosting the distribution of their vaccines and Johnson & Johnson — which is currently awaiting Food and Drug Administration approval — joining the field.

At the same time, the state tweaked how it calculates its COVID-19 positivity rate this week. Here's a look at the new stats and data from the state health department and how it factors into Utah's coronavirus situation.

Who's already vaccinated?

The Utah Department of Health began releasing vaccination data in the days after the first vaccinations went into Utahns' arms on Dec. 15. Since then, it's mostly provided a look into what types of vaccines have been distributed and where they've gone in relation to the state's 13 county health departments.

Now the health department has a larger breakdown of demographics of Utahns already vaccinated. It allows us to know the age ranges of individuals vaccinated and other characteristics to see exactly who has been vaccinated already.

We already knew who was eligible. Health care workers, emergency responders, long-term care facility patients, educators and Utahns over the age of 70 all currently qualify to receive the vaccine.

There are currently 317,603 Utahns who have received at least the first dose of the Pfizer or Moderna vaccines. Of those, 108,095 have received a second dose. That means the state has administered 425,698 out of 493,635 vaccines that have either arrived since Dec. 15 or are scheduled to arrive shortly.

  • Local health departments have emerged as the top provider of vaccines administered. With over 168,000 first doses administered and counting, they have accounted for more than half of all Utahns vaccinated as of Tuesday. Local health departments were tasked with administering vaccines to first responders and individuals 70 and older.
  • Hospital systems are the second-highest provider with 68,260 shots administered. Those were the doctors and health care workers who first received the vaccine. Since hospital systems were the first to provide shots, their group accounts for the most second doses of any group for now: 53,072.
  • Community Nursing Services, which worked with administering vaccines to teachers, is third with 39,363 people vaccinated. Long-term care facilities were fourth with 33,376 total vaccinations between federal and state pharmacies combined; private clinics, health centers and health employees were fifth at 4,452.

It's no surprise — given the large gap between the first and second providers — that approximately one-third of all Utahns vaccinated so far are 70 or older. The state health department reports 104,667 individuals 70 and over had received at least one dose of the vaccine as of Tuesday's update. Of the remaining age groups, 40 to 49 is the next highest with a little over 50,000 Utahns in this range vaccinated.

Since it's the only age group that's specifically eligible for the group without any other stipulations, it's also not shocking that individuals 70 to 79 and 80-plus have the highest percentage of vaccination rates among the state's adult population when looking at age groups.

An estimated 46% of Utahns over the age of 80 have received the vaccine and 45% of Utahns 70 to 79 have been vaccinated. All the remaining age groups — representing individuals in fields who qualified for the vaccine — fall between 6% and 14% of their age group's total population.

This graph, created by the Utah Department of Health, shows the percentage of individuals per age group that have received the COVID-19 vaccine as of Monday, Feb. 8, 2021.
This graph, created by the Utah Department of Health, shows the percentage of individuals per age group that have received the COVID-19 vaccine as of Monday, Feb. 8, 2021. (Photo: Utah Department of Health)

The state also breaks down vaccination by race/ethnicity and gender. Since the department reports that about 31% of the race/ethnicity data is unknown, that data is still a work in progress.

The data does show that women have an edge when it comes to receiving the vaccine. The gap is wider between age groups younger than 70, which could say more about the fields of vaccine eligibility than a split in the desire to get vaccinated. These gaps range from 63% women to 36% men among 30- to 39-year-olds, to 70% women and 29% men among 16- to 29-year-olds.

The gap shrinks after 70. It's 53% women to 46% men among 70- to 79-year-olds, and 57% women to 42% among individuals 80 and over.

More vaccines to come

Cox said last week that the state aimed to complete vaccinations for the 70-and-over age group in the coming weeks. State health department data and recent estimates by the Kem C. Gardner Policy Institute indicate that there are about 230,000 to 240,000 Utahns who fall under the 70-or-over category.

The rate of seniors vaccinated rose on Jan. 15 as many became eligible for the vaccine for the first time. About 27,622 Utahns above the age of 70 were vaccinated per week over the first three weeks after Jan. 15, according to data provided by the state health department.

If Utah maintained that rate for another three weeks, then roughly 181,075 Utahns 70 and older would be vaccinated through Feb. 26. That would account for roughly 75.4% to 78.7% of the estimated population. Keep in mind that Utah's vaccine supply grew during that three-week span between Jan. 15 and Feb. 5, and is expected to grow more in the coming weeks.

Cox on Thursday estimated that Utah's supply from manufacturers had moved from 33,000 per week to 42,000 to begin February. The state had some additional doses it got as a result of a deal with national pharmacy chains that were oversupplied doses in Utah, which meant at least some period of time with about 50,000 doses in a week.

"We anticipate we will continue to see these small increases each week," he said, noting these were projections and unofficial but could set the state up for "huge" spikes in how many vaccines the state receives weekly.

If the Johnson & Johnson vaccine is approved for use — which is expected — about 33,000 doses of the one-dose vaccine are expected to arrive in Utah per week by the beginning of March. Cox estimated that the state would receive over 130,000 first doses from all three manufacturers by then. If that comes to fruition, it would easily double the current delivery rate alone. He also estimated that rate would only continue to grow by April.

"To go from 33,000 a week to 130,000 (in March), and close to 150,000 to 200,000 weeks into April, just changes the ballgame for all of us," he continued. "That's what we're planning for. That's what we're preparing for."

Again, using health department data from Jan. 15 through Feb. 5, the state averaged roughly 7,254 new Utahns vaccinated per day over that three-week span. You can imagine that the number of new Utahns per day vaccinated improves if the number of doses delivered to the state every week continues to rise.

That's why the state also announced the next wave of people eligible for the vaccine during that briefing. Beginning March 1, anyone 65 or older plus anyone 18 or older with specific comorbidities will be eligible for the COVID-19 vaccine.

Those comorbidities are:

  • Anyone who is a solid organ transplant recipient
  • Anyone diagnosed with non-hematologic cancer within the past one year (excluding basal and squamous cell cancer diagnoses) or hematologic cancer diagnosed within the past five years
  • Anyone with chronic heart disease, such as chronic heart failure, ischaemic heart disease and severe valve or congenital heart disease
  • Anyone with chronic respiratory disease, which is defined as having severe chronic obstructive pulmonary disease, fibrosing lung disease, bronchiectasis or cystic fibrosis
  • Anyone with uncontrolled diabetes, which is defined by patients with an A1c of 9.0 or higher
  • Anyone with severe kidney disease, such as being on dialysis or diagnosed with stage 4 or 5 chronic kidney disease
  • Anyone with a weakened immune system from blood, bone marrow or organ transplants. This includes anyone with HIV, using corticosteroids long-term or using other immune weakening medicines long-term
  • Anyone receiving immunosuppression therapy
  • Anyone with neurologic conditions that impair respiratory function, such as motor neuron disease, myasthenia gravis, multiple sclerosis, Parkinson's disease, cerebral palsy, quadriplegia or hemiplegia, progressive cerebellar disease, epilepsy and Down syndrome
  • Anyone with asplenia splenectomy or a spleen dysfunction, such sickle cell disease
  • Anyone with a body mass index of 40 or higher
  • Stroke and dementia

It's estimated that this change will make the vaccine eligible for another 400,000 Utahns beginning March 1. With the expansion of new doses and more people to vaccinate, the state reached an initial agreement with 47 total Walmart and Smith's/Kroger pharmacies in Utah to administer vaccines for the new group.

Additional eligible groups are expected to be announced by April.

Explaining the change in Utah's positivity rate

The state health department made an adjustment to its seven-day running average positivity rate this week, which went into effect on Monday.

"We have been using percent positivity rate throughout this outbreak as a leading indicator of the spread of COVID; in addition, it also measures how much testing we're doing," said Dr. Angela Dunn, the state's epidemiologist.

Dunn explained there are actually three valid ways the Centers for Disease Control and Prevention calculate the statistic. Utah has used a "person over person" method from the beginning, which is the number of people who have tested positive over the total number of people who have been tested.

"For a person who has taken more than one test within a 90-day period, their first positive result is used; and if they do not have a positive result, their first negative result is used," she said.

That means if you tested negative on Jan. 1 and then tested negative again on Feb. 1, that second test would not be counted under this format — neither would any other test conducted between Jan. 1 and the end of March if the result remained negative.

Dunn said this format "biases our positivity rate a little bit higher," but it's also a method that's allowed experts to project surges in advance of them happening.

The state is not ditching this format. In fact, it's still on the state health department's dashboard. The state's rate fell to 15.47% through Feb. 3 with Tuesday's update. It's the same percentage that it reported on Oct. 13 as the state's COVID-19 decline continues.

This graph, created by the Utah Department of Health, shows Utah's "person over person" positivity rate throughout COVID-19 pandemic as of Tuesday, Feb. 9, 2021.
This graph, created by the Utah Department of Health, shows Utah's "person over person" positivity rate throughout COVID-19 pandemic as of Tuesday, Feb. 9, 2021. (Photo: Utah Department of Health)

However, the health department now allows users of the site to toggle to a second format: "test over test."

"This is simply the number of positive tests resulted over the total number of tests administered," she said. "So every single test reported to the Department of Health is included in this calculation."

"So if you tested negative on Jan. 1 and negative again on Feb. 1, both results would show up in the calculation. This time it leads to a bias for the rate to be "a little bit lower," Dunn added. This method lists Utah's positivity rate at 7.22% as of Feb. 3.

This graph, created by the Utah Department of Health, shows Utah's test over test positivity rate throughout COVID-19 pandemic as of Tuesday, Feb. 9, 2021.
This graph, created by the Utah Department of Health, shows Utah's test over test positivity rate throughout COVID-19 pandemic as of Tuesday, Feb. 9, 2021. (Photo: Utah Department of Health)

So what's the positivity rate? It depends on the method you're looking at. Either way, the trends don't really change. With the test over test format, Utah's pandemic positivity rate peak would be 17.87% on Jan. 1, not 33.25% as the person over person format indicated. That said, both indicated the same peak dates and recent declines in cases.

It also doesn't mean that the state is changing the formula to get back to its goal of under 5% more quickly. Under the test over test method, the state still hasn't reached that goal since late May 2020. That's also the last time the previous method reached that goal through the person over person method.

Dunn said the state's new method is one used by 37 other states, so it allows people to better compare with how all 50 states calculate rates. It also allows Utahns to better see the rates as the state increases COVID-19 testing.

"This test over test method is going to allow us to see the benefit of our increased testing capacity," she said. "We want people to get tested, and testing is a key intervention to slowing the spread of COVID."

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Carter Williams is an award-winning reporter who covers general news, outdoors, history and sports for KSL.com.


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