Vaccination enhances immunity in people who previously had COVID-19; little evidence for claim that the Amish community in Lancaster County, PA, have herd immunity

"All the Amish know we got herd immunity", "We all got the Covid, so why would you get a vaccine?"
Unsupported: In the spring of 2020, COVID-19 cases were common among the Amish community of Lancaster County in Pennsylvania, leading to the report that the community had reached herd immunity. However, the Amish community in Lancaster County has a low rate of COVID-19 testing, making it difficult to confirm this claim.
Inaccurate: COVID-19 vaccination boosts immune protection in those who previously had COVID-19. Additionally, natural immunity post-infection is variable, while vaccination provides safer and more reliable immunity. The claim that people who previously had COVID-19 don’t need to be vaccinated isn’t in line with recommendations from public health experts.
In the spring of 2020, there were many cases of COVID-19 among the Amish and Mennonites of Lancaster County, PA. Because an estimated 90 percent of households had at least one COVID-19 case, this has led to claims that these communities have achieved herd immunity in the area and, because of this, the Amish don’t need to be vaccinated. However, due to low COVID-19 testing among Lancaster County Amish, it is difficult to confirm the herd immunity claim. Additionally, people who previously had a COVID-19 infection benefit from receiving the vaccines by boosting their protective immunity in a safer and more reliable way.

FULL CLAIM: "All the Amish know we got herd immunity", "We all got the Covid, so why would you get a vaccine?"


A transcript of a report on the show “Full Measure with Sharyl Attkisson”, published on 10 October 2021, contained several claims about how the Amish community of Lancaster County, Pennsylvania, have coped with COVID-19. The Amish are an American Protestant group that live a preindustrial way of life, eschewing most of technology and living in close communities. In Lancaster County, the Amish together with the Mennonites, make up nearly 8% of the population.

Speaking to Attkisson, Calvin Lapp, an Amish Mennonite claimed that “all the Amish know we got herd immunity”, because “the whole Church gets [sic] coronavirus”. As we’ll show below, this claim is unsupported.

The claim that the Amish community of Lancaster County reached herd immunity likely comes from Allen Hoover, the administrator of the Parochial Medical Center located in Lancaster County. In late March 2021, Hoover estimated that about 90 percent of Plain households–Plain people is another term used to refer to the Amish and Mennonites–had experienced at least one COVID-19 case. According to Hoover, in the spring of 2020, COVID-19 spread throughout the Plain community of Lancaster County, allowing them to achieve herd immunity.

However, this claim was questioned by public health experts, with many expressing concern that a misplaced faith in herd immunity might compromise measures to limit the spread of SARS-CoV-2. Speaking to Lancaster Online journalist Nicole Brambila, infectious disease epidemiologist David Dowdy from the Johns Hopkins Bloomberg School of Public Health, said that “there could easily still be pockets of the (Plain) community that have not been infected, and if they’re infected, there’s a real risk of having an outbreak”.

Outbreaks of COVID-19 have happened in Amish communities. An article from the U.S. Centers for Disease Control and Prevention (CDC) reported on one such outbreak in a rural Ohio Amish Community in May 2020, and how “social gatherings, important in Amish communities, likely contributed to transmission of SARS-CoV-2”[1].

Another issue is the lack of COVID-19 testing among the Plain, making it hard to either prove or disprove the claim of herd immunity. A review of the literature on Amish health culture, found that a number of barriers limit the use of health screenings among Amish communities, including a lack of knowledge about these screenings and the costs of tests[2]. In Brambila’s article, Hoover “speculated that among those displaying symptoms, fewer than 10% consented to be tested” in Lancaster County. These barriers, however, are not insurmountable; during the outbreak in the Ohio Amish Community, active support for testing from community leaders helped overcome some of these barriers[1].

In the Full Measure report, Attkisson mentioned these doubts about herd immunity, noting that “outsiders are skeptical, and solid proof is hard to come by”.

Later in the Full Measure report, Lapp explained that, because of herd immunity, the Amish won’t get the COVID-19 vaccine. “We all got the COVID, so why would we get the vaccine?” he asked. This reflects a common misconception of vaccination and infection-acquired immunity as mutually exclusive, rather than complementary, approaches to protection from infectious disease (false dilemma). As we’ll show below, there are good reasons for getting the COVID-19 vaccines even if you’ve been previously infected.

Some individuals who previously had COVID-19 believe they don’t need to be vaccinated because they have natural immunity. Health Feedback covered this belief in an earlier review. While natural immunity may provide some degree of protection against SARS-CoV-2, research from the CDC has shown that the combination of vaccination and natural immunity decreased the risk of reinfection 2.34 times compared to individuals who were unvaccinated[3].

For this reason, experts recommend that people who previously had COVID-19 get vaccinated. Johns Hopkins Bloomberg School of Public Health infectious disease expert Anna Durbin explained the benefits of vaccination thusly:

“When you introduce the vaccine to someone who’s already had COVID-19, the body says, ‘Hey, I remember that, I’m going to stimulate the immune response so you’re protected’. You’re pumping up your antibodies to higher levels so they can stop the virus before it enters your system”.

Additionally, as immunologist Jennifer T. Grier from the University of South Carolina explained in an article in The Conversation, not everyone who gets infected will develop the same protective immunity. “As many as 9% of infected people don’t have detectable antibodies, and up to 7% of people don’t have T cells that recognize the virus 30 days after infection”. Vaccines, on the other hand, offer “safer and more reliable immunity than natural infection”.

It’s also important to remember that to have natural immunity, one must first survive COVID-19. While the overall survival rate of COVID-19 is relatively high compared to other infectious diseases like Ebola, survival doesn’t imply complete recovery, as COVID-19 survivors can suffer from long-term health impacts. As Rockefeller University immunologist Michel Nussenzweig told Science, “What we don’t want people to say is: ‘All right, I should go out and get infected, I should have an infection party. Because somebody could die”. An alleged infection party in Edson, Canada, landed multiple partygoers in the ICU in September 2021.

Throughout the pandemic there have been numerous claims that Amish communities were spared from COVID-19 as a way to downplay the seriousness of the pandemic. In the Full Measure report, Attkisson claimed that there’s no evidence the Amish suffered any more deaths compared to places that adopted protective measures against the disease, adding that “some claim there were fewer here”. Fact checks of claims related to the Amish being spared from COVID-19 can be found here, here and here. Speaking to the AFP, Allen Hoover, said that the opposite was true: “Because the Amish are such a tight knit community, and because they have largely ignored all safety protocols among themselves, they have experienced a much higher than average COVID-19 infection rate”. 

In summary, the claim that the Amish community of Lancaster County, Pennsylvania, has reached herd immunity hasn’t been confirmed via COVID-19 testing yet. Furthermore, Lapp’s claim that herd immunity makes it unnecessary for the Amish to get the COVID-19 vaccines contradicts research findings and recommendations by public health experts. The combination of previous SARS-CoV-2 infection and vaccination provides greater protection than natural immunity alone, and vaccination provides safer and more reliable immunity than COVID-19 infection. For these reasons, public health authorities recommend that previously infected people get vaccinated.



Published on: 13 Oct 2021 | Editor:

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