At a denominational meeting 20 years ago, a group of activists unrolled huge banners proclaiming “The body of Christ has AIDS.” Today the body of Christ has swine flu.

The new pandemic most likely will be less deadly than HIV and involve no activists. But it still will affect the church.

Formally known as influenza A (H1N1), the disease appeared in March in Mexico and the World Health Organization declared it a Phase 6 pandemic in June.

The pandemic is an issue for church leaders because the church is a petri dish for disease. It brings large groups of people together in confined spaces. Its commitment to inclusion and welcome -- frequently, alas, more often proclaimed than enacted -- throws together strangers from disparate backgrounds. Its social and liturgical practices, such as hand-shaking, the kiss of peace and communion, are good ways to transmit germs. It is almost as bad as a preschool.

Influenza concerns already have affected church practices. In April, the Religion News Service reported that some clergy were encouraging special precautions in their congregations. Some Mexican churches closed; U.S. Catholic bishops did not go that far, but did encourage priests to use anti-bacterial soap before Mass and sick congregants to stay home. “It’s not sinful to miss Mass if you’re sick,” one said. Some dioceses stopped giving the chalice to congregants, while at least one Protestant church used individually wrapped communion elements.

As church leaders consider how to respond to the H1N1 flu, they should keep in mind this is not a new issue for American churches. In the 1870s physicians started blaming germs for transmitting disease and quickly urged the church to abolish the common communion cup. The church, argued a New York doctor in 1887, offers a rich opportunity for transmitting disease. “The old lady, pure in mind and body, sips from the cup which has just left the lips of one physically impure.”

While some clergy rushed to defend the traditional practice, some ministers and physicians invented (and profited from) the individual communion cup. One Methodist pastor saw the revised practice as theologically correct. “There is real communion where a score or more persons, each with a clean cup in hand, all take the sacrament at the same time.” While clergy debated the theology of the individual cup, physicians and laity embraced the new practice enthusiastically. One doctor, writing in the Journal of the American Medical Association, noted that “the laity of the churches are quicker to see the need of sanitary communion reform and the good features of the individual cups than are the pastors.”

Some churches tried to restore the common cup after the liturgical reforms of the mid-20th century but faced resistance from the pews. In 1978 a Lutheran layman found it “hard to believe that my church, guided by well-meaning but unrealistic theologians, is really going to take this giant step backward into the Dark Ages.” The appearance of AIDS in the 1980s made the fight even more intense.

The current epidemic, of course, is different from AIDS. Quick media coverage raised the alarm, but much of the coverage was more hype than fact. The disease has killed people around the world, but fewer than most seasonal influenzas. Even if H1N1becomes more virulent this winter, it will not have the same mortality rate as HIV. Swine flu does not carry the same stigma as AIDS; since the epidemic will not last as long as AIDS, it is unlikely to give rise to activist groups.

These other disease scares do, however, offer some lessons as churches deal with H1N1. People in the pews will avoid physical contact, abstain from communion and possibly even stay home from church to prevent infection. Churches can address these concerns with well-articulated if temporary policies, following the lead of many schools:

• Put away the common cup for the duration, using individual cups until the flu runs its course.

• Use hand sanitizer in Sunday school classrooms.

• Teach people alternative ways to pass the peace, including the elbow rub or the fist bump in place of handshakes or hugs.

• Encourage sick people to stay home.

Many clergy -- and laity -- may find these changes theologically distasteful or personally disturbing. A clear rationale may address these concerns, as will the goal of reversing them at the end of the epidemic.

As with the cup controversy and AIDS, churches’ responses to the epidemic will reflect a fear of strangers as well as a fear of disease. Anthropologist Mary Douglas argues that fear of contagion reflects a risk to the social body -- the community -- as well as the physical body. The communion cup controversy was driven in part by the presence of strangers in the pew, and the response to AIDS was shaped by concerns about immigration and sexuality.

It’s no surprise that the first reaction to the “Mexican” swine flu was a proposal to close America’s southern border. This fear of the stranger will continue to influence how churches react to the epidemic. The cup controversy also suggests that the laity will accept guidance about disease and its transmission more readily from physicians than from their pastors.

Most importantly, these previous controversies suggest that contagion is inescapable in the church. As long as Christians continue to eat together, to embrace, to breathe the same air -- in sum, to be human -- disease can spread. That doesn’t mean church leaders shouldn’t enact thoughtful policies to reduce the chance of transmission, but it does mean the church cannot be sterilized. A late 19th-century critic of the individual communion cup spun a satire of the germ-free church, with worshippers having their own communion cups, their own hymnals and their own hermetically sealed chambers in which to worship God.

The body of Christ has the swine flu, but it will survive.