Following the herd
Researchers watch Amish community as 90% of households likely hit by COVID-19
LANCASTER — Late last spring a COVID-19 wave tore through the Plain community when they resumed church services, infecting an untold number of Amish and Mennonites in Lancaster County.
The administrator of a medical center in the heart of the Amish community in New Holland Borough estimates as many as 90% of Plain families have since had at least one family member infected, and that this religious enclave achieved what no other community in the United States has: herd immunity.
“So, you would think if COVID was as contagious as they say, it would go through like a tsunami; and it did,” said Allen Hoover, an Old Order Mennonite and administrator of the Parochial Medical Center, a clinic that primarily serves the Plain community.
Public health officials and epidemiologists did not dispute the widespread outbreak Hoover described. But they voiced concern that a misplaced perception of herd immunity in a population that makes up 8% of Lancaster County may compromise the effort to turn the tide on the pandemic.
As Hoover observed, faith in herd immunity has prompted members of the Plain community to relax on key mitigation efforts such as masking and social distancing, and they may see little reason to be vaccinated.
Additionally, it is unknown whether achieving herd immunity last year would be beneficial now.
Six infectious disease experts expressed unease with a reliance on the notion the Plain community had achieved herd immunity here. And they pointed out that past infections and existing antibodies may provide limited protection.
“Herd immunity is only true at a given point in time,” said Eric Lofgren, an infectious disease epidemiologist at Washington State University. “It’s not a switch that once it gets thrown, you’re good. It’ll wear off.”
This collision of science and personal experience could leave Lancaster County vulnerable just as county health officials seek to make progress vaccinating residents against COVID-19.
“You can have a long period where you think everything is OK, but you have this whole population that’s susceptible,” said David Lo, professor of biomedical sciences and senior associate dean of research at the University of California, Riverside.
Lo said: “All it takes is one person who’s contagious to give you this sudden outbreak.”
A real risk
Hoover agreed with these epidemiologists.
He acknowledged that face masks and social distancing have been critical for mitigating the spread of COVID-19; he wears a face covering when interacting with non-Amish. But he also knows many in the Plain community don’t take the same precautions.
“As a general rule, we want to respect those around us,” said Hoover, who has been the medical center’s administrator since 2004. But because of perceived immunity, Hoover said, the Plain community believes public health directives don’t “apply to us.”
It’s a perspective Hoover understands, but doesn’t share.
“We should be careful that we’re not the cause of it spreading,” Hoover said.
The Parochial Medical Center is not the only medical provider that caters to the Plain community, but with 33,000 active patients, it is arguably the largest.
The Plain community in Lancaster County, which includes Amish and Mennonites, is not insignificant. Combined, it represents nearly 8% of the county’s population of just more than 545,000 residents, according to estimates from Elizabethtown College’s Young Center for Anabaptist and Pietist Studies.
The dearth of COVID-19 testing among the Plain doesn’t just mean a lack of scientific certainty.
“The reason it’s important is because it’s unlikely that 100% have had the disease,” said David Dowdy, a professor in the epidemiology department at Johns Hopkins Bloomberg School of Public Health.
An outbreak among the Plain would impact the wider community because while these religious sects are insular, they are not isolated. The Plain mingle with the English, as they refer to their non-Amish neighbors, at grocery stores, their places of business and other public places.
“There could easily still be pockets of the (Plain) community who have not been infected, and if they’re infected, there’s a real risk of having an outbreak,” Dowdy said.
‘It was bad’
The Plain community followed the example of its English neighbors and shuttered schoolhouses and canceled biweekly church services when the novel coronavirus threatened to overwhelm Pennsylvania’s health care system last spring.
Initially, compliance with public health directives was about not being offensive to non-Amish neighbors, Hoover said.
But as the pandemic wore on, messages from skeptical lawmakers and English neighbors suggested that the virus wasn’t a big concern.
“The Amish are a distinct group, but they also respond, in many ways, like many rural Lancastrians,” said Steve Nolt, interim director of the Young Center. “I think there was a lot of non-Amish influence on the Amish.”
As their English neighbors resumed pre-pandemic activities, the Plain community did as well, Nolt and others said.
By late April, when Pennsylvania was still under stay-at-home orders, the Plain community had resumed worship services, where they shared communion cups and holy kisses, a church greeting among believers.
Infections quickly followed.
“It was bad here in the spring; one patient right after another,” said Pam Cooper, a physician’s assistant at the Parochial Medical Center.
Just how deep into the community the infections spread is impossible to know. Hoover speculated that among those displaying symptoms, fewer than 10% consented to be tested.
In late April and early May, when Hoover said the virus ran unimpeded through the Plain community, the county’s positivity rate — the percent of positive tests — exceeded 20%, its highest of the pandemic, according to Covid Act Now, a nonprofit that provides local disease data.
If Hoover’s assessment is accurate, and if more Plain patients had been tested, the positivity rate could very well have been higher.
While so few were tested, many exhibited all the symptoms that have become so emblematic of the disease.
Cooper estimated the medical center saw — on average — nearly a dozen infections a day, or roughly 15% of the patients it serves daily.
The disease, as has been true in the wider community, knew no boundaries. Hoover became infected in November; at least one of his children was infected twice.
“It really went through pretty quick, in a few weeks,” Cooper said.
The number of patients ebbed in the summer before picking up again in the fall, although not at nearly the rate as was seen in the spring.
Cases now are rare. Hoover said recently that the center hasn’t had a patient present with COVID-19 symptoms in roughly six weeks.
‘Test the herd’
Epidemiologists from the University of Pittsburgh, Washington State, Johns Hopkins, Emory and the University of California all said a widespread outbreak leading to herd immunity in the Plain community would be rare, but possible.
“It’s extremely unusual,” Lofgren, at Washington State University, said of COVID-19 herd immunity. “It would be the first general population in the United States that’s done it.”
Significant outbreaks have been identified elsewhere.
The CDC, for example, studied COVID-19 outbreaks among smaller Amish communities in rural Ohio and Indiana.
Unlike the outbreak Hoover described in Lancaster County, however, the Ohio and Indiana communities conducted testing.
“They really contributed to a lot of spread of COVID in the community,” said Shirley Bixby, director of nursing for the Ashland County Board of Health in northeastern Ohio. “It was quite nerve-wracking.”
In Indiana, COVID-19 infections were so common among the Amish that residents believe most had been exposed.
At the height of the summer outbreak, seven out of 10 COVID-19 tests came back positive, said Dr. Daniel N. Kragt, a physician at Dayspring Christian Health Care in Middlebury, Indiana.
For all the tests Kragt conducted, about 40% of Amish patients declined.
Making scientific conclusions about immunity is difficult, Kragt noted, because very often “the herd doesn’t want” to be tested.
“To say you have herd immunity, you’d actually have to test the herd,” Kragt said.
No ‘magic number’
Herd immunity — either through infection or vaccination — has been touted as the way back to normal.
“The only true herd immunity that we can bring as a community is for people to be vaccinated,” said Alice Yoder, executive director of Community Health at Penn Medicine Lancaster General Health.
Because immunologists don’t yet know what the threshold is for COVID-19 immunity, Dr. Anthony Fauci, the nation’s top infectious disease expert, has said the coronavirus could require vaccination rates as high as 90%.
“The key is that there is not necessarily a magic number,” said Dowdy, at Johns Hopkins Bloomberg School of Public Health.
As the United States races to stay ahead of virus mutations, the more pressing issue — these experts said — was vaccine hesitancy. As of March 16, there were two other mutations in Pennsylvania: 68 cases of the UK variant and one South African case, according to the CDC.
“The higher the vaccination in the (Plain) community, the better it will be for the entire community,” said Dr. Amesh Adalja, an infectious diseases physician and senior scholar at the Johns Hopkins Center for Health Security.
A hard sell
Vaccine efforts among the Plain community could prove challenging.
“I think it will be a very hard sell,” Hoover said.
The Amish have been persuaded to embrace mass vaccination efforts before, most notably after a polio outbreak in 1979 and a rash of measles in 1991. This has left health officials hopeful the Anabaptists will respond again.
The way Dr. Holmes Morton sees it, these religious sects must take responsibility for getting vaccinated to protect their Lancaster County neighbors.
“I just think the Plain community has to get involved in a public-health sense,” said Morton, founder of the Central Pennsylvania Clinic in Belleville, Mifflin County.
“Just because you’re Plain doesn’t mean you’re exempt,” Morton said. “God helps those who help themselves.”