Michigan health department: 70% vaccination goal not based on herd immunity

Craig Mauger
The Detroit News

Lansing — Michigan's target of vaccinating 70% of the adult population is not based on reaching herd immunity, a spokeswoman for the state health department said Monday as a key Republican lawmaker questioned why those who are recovered from the virus aren't included in the tally.

On Thursday, Democratic Gov. Gretchen Whitmer unveiled her plan for relaxing COVID-19 restrictions as more residents get their first dose of the vaccine. The final phase of the new initiative would lift the statewide order on masks and gatherings two weeks after 70% of the adult population has had their initial dose.

On Monday, Whitmer's administration noted 50.4% or 4.08 million of the state's nearly 8.1 million adults age 16 years or older had received at least one dose, while almost 39% or 3.15 million were fully vaccinated. Under Whitmer's plan, restrictions begin lifting, starting with limitations on in-person office work, two weeks after the percentage hits 55%.

During a Monday radio interview, Senate Majority Leader Mike Shirkey, R-Clarklake, credited the governor for setting a metric-based reopening plan but argued that the plan should take into account people who have already had the virus. Shirkey said the state "should be opening this week" if the goal is immunity.

Elizabeth Hertel, director of the Michigan Department of Health and Human Services, has said COVID-19 herd immunity would be reached when about 80% to 85% of Michigan's population is immune or has been vaccinated.

However, the 70% target is not based on community immunity or herd immunity, said Lynn Sutfin, spokeswoman for the Michigan Department of Health and Human Services. It's an "operational goal identified at the beginning of the vaccination campaign, based on the understanding of potential availability of vaccine and ages that would be eligible for vaccination," Sutfin said.

There's not enough information currently available to say if or for how long after an infection someone is protected from COVID-19, she added.

"Early evidence suggests natural immunity from COVID-19 may not last very long, but more studies are needed to better understand this," Sutfin said. "For this reason, people who have already had the virus but haven’t been vaccinated aren’t included in the 70% calculation."

Asked if the Whitmer administration has a goal for when community immunity would be reached, Sutfin said the federal government has not released such guidance and "there is still much to learn about COVID-19."

During a Senate hearing in February, Elizabeth Hertel, director of the Department of Health and Human Services, said herd immunity would be reached when about 80% to 85% of Michigan's population is immune or has been vaccinated.

A person is not fully vaccinated until two weeks after the second dose of a two-dose vaccine or two weeks after a one-dose vaccine, according to the Centers for Disease Control and Prevention.

Michigan reported 5,035 new COVID-19 cases on Monday, putting the overall total of infections since the beginning of the pandemic at 849,420.

In an interview on WJR, Shirkey said more than 2 million Michigan residents had had the virus. He based that number on studies that have estimated that at least three times as many people have had COVID-19 as have tested positive for it, said Abby Walls, Shirkey's spokeswoman.

"What I’m suggesting is by the state’s own data, more than half of the Michigan people that are eligible have already received their shots," Shirkey said. "If you add to that the 2 million plus people who have already gotten COVID and recovered from it and their natural immunity that they acquired because of that, we are already at the 70%."

But it's not clear how long a person is protected from getting sick again after recovering from COVID-19, according to the Mayo Clinic. And it's possible individuals can get COVID-19 again even if they have the antibodies. Similarly, the CDC recommends that people who have recovered from COVID-19 get vaccinated.

Senate Majority Leader Mike Shirkey, R-Clarklake, argues that Michigan has reached 70% adult immunity from COVID-19 based on vaccination rates and estimates from studies of the number of residents who have been infected with the virus.

"Getting COVID-19 may offer some protection, known as natural immunity," the CDC says. "Current evidence suggests that reinfection with the virus that causes COVID-19 is uncommon in the months after initial infection, but may increase with time."

The group Committee to Protect Health Care slammed Shirkey's statements on Monday. The Senate leader's claim that 70% of Michigan residents are already immune to COVID-19 is "false and dangerous," said Dr. Farhan Bhatti, a family physician in Lansing and Michigan state lead for the committee.

"While Michigan has made great strides getting residents vaccinated and protected, we have a ways to go until we meet that threshold where the virus stops spreading and mutating," Bhatti said.

Michigan has led the nation in new cases per population for more than a month, according to CDC tracking.

The 70% vaccination goal was originally announced in January.