While other researchers study whether people need booster doses over time to maintain protection, Karger said the U study will establish whether the initial doses work in the immunocompromised population. The study is part of a $6.7 million grant the U received as part of the national SeroNet research group, she said.

Unvaccinated people with weakened immune systems had been protected by mask-wearing and social distancing that reduced viral transmission in their communities, but those practices have declined over the past month since state mandates were lifted.

Vaccination progress in Minnesota has been credited with shortening the duration and severity of the spring wave — with more than 3 million people 12 and older in the state receiving at least a first shot and nearly 2.8 million people completing the one- or two-dose series.

The U study group, according to the Star Tribune report, is recruiting 2,000 people who have either recently received a vaccine or are about to receive their first dose — a challenge now that 64% of all eligible people 12 and older have received their shots — and will monitor the antibody levels in their blood over two years.

“Minnesota has been so successful with vaccination … that our pool is ever-shrinking,” Karger said.

The U planned last fall to study the duration of natural immunity in people after coronavirus infections. While public health guidance suggests protection lasts 90 days in most people, Karger said there is credible evidence that protection lasts eight months or more in people with healthy immune systems.

“Ninety days seems to be old news,” said Karger, although the duration of protection in immunocompromised people remains less clear.

Federal approval of COVID-19 vaccines in December shifted the U research toward the duration of immunity after people received their shots.

“I do think the booster shots and future shots and timing and doses are going to be really important questions that we need to tackle,” she said.

source: HealthWise