Delta variant becomes most prominent COVID-19 strain in Iowa

The highly contagious Delta variant of the novel coronavirus is now the most dominant strain in Iowa.

Delta accounted for more than half of positive coronavirus tests in Iowa that included a variant during the last two weeks in June, according to the Iowa Department of Public Health.

This new strain of the coronavirus, which has been labeled as a “variant of concern” by public health officials, was first detected in Iowa on May 4.

“Since that report, we have confirmed increasing incidences of the variant throughout the state, and Iowans should assume it is circulating in their community,” IDPH spokeswoman Sarah Ekstrand said.

The best tool to prevent spread of the coronavirus are vaccines.

“With the rise in prevalence of the Delta variant, we urge all Iowans to get vaccinated for COVID- 19 as soon as possible,” Ekstrand said. “We are committed to ensuring that all Iowans have access to the vaccine and that they feel confident in their decisions to get vaccinated.”

As of this past week, 45.9 percent of all Iowa residents were fully vaccinated, or 54.1 percent of those aged 12 and older, according to state coronavirus data.

But Iowa’s current vaccination rate likely is not enough to prevent the virus from gaining more prominence across the state. Without that firewall against spread of the virus, there’s more opportunity for the virus to mutate and for more variants to emerge as a result.

“It’s really urgent now that we reach out to those who haven’t had easy access to vaccine or have been waiting to get the shot,” said Dr. Dan Diekema, University of Iowa Hospitals and Clinics infectious disease specialist. “We need to get them vaccinated as soon as possible.”

Delta now the dominant variant in Iowa, nationwide

This new strain of the coronavirus has been labeled as a “variant of concern” by federal and global health officials because of its high rate of transmission.

First detected in India in December, the Delta variant since has made a rapid sweep throughout parts of the world before it was first recorded in the United States in March.

The variant now accounts for roughly 52 percent of coronavirus infections across the country, according to new estimates this week from the U.S. Centers for Disease Control and Prevention.

In the week ending June 25, the State Hygienic Lab found the variant in 25 of 47 positive test results that included a variant of the coronavirus. That accounts for 53 percent of variant strains identified through routine sequencing.

In the previous week, the variant was detected in 51 percent — or 36 of 70 — positive test results that included a variant, according to the IDPH.

The second most common variant found in Iowa is the alpha variant, according to the state lab. That variant, first detected in the United Kingdom, ranged between 20 percent to 30 percent of positive tests sequenced over the two-week period in June.

The state lab mostly was sampling from Test Iowa sites. With the program’s closure, state officials are requesting testing labs send positive samples to the State Hygienic Lab for sequencing, Ekstrand said.

Unvaccinated Iowans face the greatest risk from Delta

COVID-19 vaccines available in the United States have proved to prevent severe outcomes and death, meaning the new variant poses the most risk to those who aren’t vaccinated, Diekema said.

Hospitalizations have increased across the state in recent weeks, but Eastern Iowa facilities say the vast majority of their COVID-19 patients have been unvaccinated against the virus.

Diekema said scientists still are determining whether the Delta variant causes more severe disease in infected individuals.

However, the IDPH’s Ekstrand noted some health care providers across the state have reported “occasionally” seeing vaccinated Iowans testing positive for COVID-19.

It still is possible for vaccinated individuals to test positive for the virus with this variant, but more often than not, Diekema said these patients have no symptoms or very minor symptoms. These patients pose a very low risk of transmitting the virus to others, he added.

The state does not have a database where immunization records and positive COVID-19 results exist together, meaning state public health officials are unable to determine how many breakthrough cases occur in vaccinated Iowans.

“We expect to see a small percentage of infections among people who have been vaccinated but whose immune systems didn't quite learn to have a strong enough protective response,” Ekstrand said.

The variant is also able to evade some antibodies created from vaccination and natural infection, new research has found. A single shot of a two-dose vaccine “barely” offers any protection against the Delta variant, according to a report published this week in the journal Nature.

However, scientists conducting the study did find two shots of the Pfizer-BioNTech or AstraZeneca vaccine offers significant protection against the variant.

Comments: (319) 398-8469; michaela.ramm@thegazette.com