Grand Forks County COVID figures tick back upward

The coronavirus is gaining traction in Grand Forks County as countywide vaccination figures stay well short of a relatively pessimistic goal for so-called “herd” immunity.

More county residents are testing positive for COVID-19 and a greater proportion of tests overall are coming back positive, according to data presented Monday to Grand Forks City Council members at an otherwise humdrum council meeting. About 0.6 county residents out of 100,000 tested positive for the virus each day in early July, and that figure has risen to 7.35 as of Monday. Meanwhile, the “positivity rate” of Grand Forks County coronavirus tests has risen from 1% to 5.3% in approximately that same span as the absolute number of people seeking a COVID test rises, too.

“We’re more worried about the sudden increase than we are about the actual numbers,” Michael Dulitz, Grand Forks Public Health’s lead COVID data analyst, told council members. That, he told the Herald afterward, is because any time COVID metrics ratchet up, it leads to an increase in hospitalizations and, later, an increase in deaths.

Dulitz said the health department believes those rises are due to the coronavirus' "delta" variant .

“We have every reason to believe that it would be delta variant, but we can’t fully confirm that,” he said. “We just don’t have the data to fully say it’s that, but based off of the increase in the proportion of cases being attributed to the delta variant, we would certainly believe that that’s the case.”

Studies indicate the delta variant is considerably more contagious than the one that swept across the United States in early 2020 and has lingered ever since.

As of Sunday, Aug. 8, about 31,400 Grand Forks County residents had been fully vaccinated, which is about 8,400 people short of the threshold at which health department staff hope the county will reach “herd” immunity, a situation in which the virus runs out of epidemiological room to spread to another person because enough people are immune to it.

Health department staff hope the county achieves herd immunity when at least 60% of its residents get a vaccine, but that figure, even before the delta variant rose to prominence, was a relatively unambitious one because some experts believe the threshold for herd immunity could be in the 70-80% range.

The more contagious delta variant might push those thresholds considerably higher. A disease’s r0 – pronounced “r-naught” – value indicates how contagious it is. It represents the average number of people who could end up being infected by a single person with the disease, assuming no epidemiological safeguards are in place, such as social distancing or masks. The higher the number, the more contagious the disease.

Studies of the first wave of COVID-19 put its r0 figure between 2.4 and 2.6, which means that a single infected person would spread the disease to about that many people. Early indications put the delta variant’s r0 figure between 5-8, which, in turn, would mean that a considerably higher proportion of people would need to be vaccinated to hit herd immunity because more people would need to be immunized for the variant to run out of figurative room.

As of Sunday, about 45.2% of Grand Forks County residents had been fully vaccinated.