In the last years of the campaign to eradicate smallpox, the health workers fanning out to the disease’s stubborn hot spots developed a strategy: Official reports or gossip relayed by missionaries and village kids would identify someone carrying the disease’s telltale blisters. The health workers would track down the unlucky person, and then launch into quick interviews with them: What did they do everyday? Where did they go? Who were their closest contacts? Then they would find those people, assess whether they were infected, and repeat the process, rapidly constructing a map of an invisible network nestled inside a village’s visible society. Their final action would be to vaccinate everyone within the network, drawing an immunological barrier around the group and blocking the virus’s transmission to the rest of the village.
This ring vaccination strategy, as it came to be called, used fewer vaccine doses and required fewer personnel than the mass vaccination campaigns that preceded it. It closed the loop around the last natural case of smallpox in 1977, and allowed it to be eradicated—the only human disease for which that’s happened—in 1980. Four decades on, the World Health Organization and major governments, including Canada, the United Kingdom, and the United States, have said ring vaccination is the preferred strategy for controlling the new pox epidemic: monkeypox.
It began spreading in Europe in May and has now caused more than 15,500 cases worldwide , including more than 10,000 in Europe and almost 2,600 in the US. The strategy makes sense, hypothetically: Compared to trying to vaccinate everyone , ring vaccination is a faster, cheaper, more targeted means of getting a pathogen under control. But whether ring vaccination is achievable now for monkeypox is an open question.
“I don’t think the horse is out of the barn yet,” says Jeffrey Koplan, a professor of medicine and global health at Emory University and former director of the Centers for Disease Control and Prevention, who administered ring vaccination as a smallpox field worker in Bangladesh in 1973. “We’re not dealing with measles or chickenpox, or with the issues of the Covid pandemic. We’re dealing with a relatively slow-spreading entity, with a classic pattern of spread.
” That classic pattern means that the virus spreads from one person to another during a close encounter, either the mucosal-membrane contact of sex or intimate skin-to-skin contact. It’s the same pattern by which sexually transmitted diseases spread, rather than the one-to-many distribution of airborne pathogens such as the Covid virus and measles. Monkeypox, which causes painful pus-filled blisters, is not considered an STD, but the current global outbreak has been linked to sexual behavior.
To the degree there is data, the majority of cases have been among gay or bisexual men who report having had multiple partners. So the ring vaccination method proposed in the White House’s strategy has been to vaccinate people who know or suspect they have been intimate with someone who developed monkeypox, or who had multiple sex partners in a place where monkeypox is known to be spreading. Ring vaccination worked for smallpox because a person-to-person pattern of spread makes it possible to predict and interrupt chains of transmission.
The process is straightforward: Find the people most at risk of infection, give them shots. But to take those actions today to curb monkeypox, you have to find cases, you have to identify their likely contacts—and, crucially, you have to have vaccines to distribute. So far, in the US, none of those efforts are going well, and epidemiologists, scientists, and experts in LGBTQ sexual health are skeptical that ring vaccination will succeed.
For one thing, the numbers are rising too fast. “If there were five people, we could do our best to try to do ring vaccination,” says Gregg Gonsalves, an assistant professor of epidemiology at the Yale School of Public Health and a longtime HIV/AIDS activist. “But now, when you’re dealing with potentially thousands of cases in the US, trying to contact-trace them all and vaccinate all their contacts doesn’t seem like it’s going to happen.
” So any effort to identify people most at risk, to alert them and get them protected, will have to rely on incomplete information. If ring vaccination represents a fence around an infection risk, “there are huge gaps in the fence,” says Steven Thrasher, an assistant professor of journalism at Northwestern University and author of a new book on the interplay of viral infections and inequality. “As far as I can tell, contact tracing has been haphazard, to say the least, and testing was basically unavailable until last week,” agrees Angela Rasmussen, a virologist and associate professor at the Vaccine and Infectious Disease Research Organization-International Vaccine Centre at the University of Saskatchewan.
“Vaccine’s being released in dribs and drabs, and it seems like whoever can sign up fast enough can get one. But that’s not ring vaccination. That’s just offering doses to people who might be at risk.
” There’s a lot to unpack here, and plenty of blame to go around. Start with the vaccines. Monkeypox, which spreads to people from wildlife as well as person to person, has been a constant presence in Africa for decades .
(Whether the international community should have started caring about it back then, as opposed to just tuning in now, is a discussion worth having. ) There are two vaccines potentially applicable to monkeypox: the old smallpox vaccine, which was stockpiled against potential bioterrorism, and a newer vaccine with fewer side effects. When the US government first took notice of the outbreak in late May, it had only 32,000 two-dose courses of that safer vaccine available in the Strategic National Stockpile.
Another million doses were hung up—in bottles and ready to ship—at a plant in Denmark, but the Food and Drug Administration had not approved their distribution. Earlier this month, the Department of Health and Human Services placed orders for 5 million doses of the newer vaccine, but most won’t arrive until next year. The limited doses available were sent out to state health departments under an HHS algorithm that calculated a ratio of cases already detected to the number of people believed to be at highest risk.
That sent most of them to big cities: New York, Los Angeles, San Francisco, Chicago, among others. In New York City, the online sign-up for 9,200 vaccination appointments filled in 7 minutes . That privileges the extremely online: people who can afford broadband and have the leisure to monitor a website and hammer a mouse button.
“When there’s such scarcity, equity is impossible,” says Joseph Osmundson, a queer activist and author, and a molecular microbiologist and clinical assistant professor at New York University. “Only people who are immensely socially connected, and with ample time and ability to advocate for themselves, are able to get access. It makes it not possible to reach the people who may need it most.
” Getting some people vaccinated is better than none. But for ring vaccination to succeed, the people first in line shouldn’t be the wealthiest or most computer-savvy. They should be those at greatest risk of spreading the disease.
In the last days of the smallpox campaign, that meant the family next door to an infected person, not someone on the other side of the village. Figuring out the social networks within which monkeypox is spreading, in order to interrupt them, has been difficult. The first international distribution has been tentatively traced to gay and bisexual men, presumably affluent and mobile, who picked up the infection at parties in Europe .
Their exposure was probably sex, or possibly dancing closely at a sweaty shirtless rave—but either way it’s likely they would not have known the names of some of their companions or partners. A lack of names and contact information makes it difficult to draw a prediction about transmission, or act on one. “These networks are opaque and transitory,” Gonsalves says.
They’re also not hermetically sealed. In Georgia—home to two huge Pride festivals in Atlanta, but also to a persistent HIV epidemic in its poorest rural counties—monkeypox already is disseminating out from that first ring of affluent urban men. “A larger proportion of the men with monkeypox here in Georgia are Black, which is a different demographic than the white circuit-party set that we’re seeing in other cities,” says Justin Smith, director of the Campaign to End AIDS at the Atlanta HIV-care organization Positive Impact Health Centers.
“And this is the pattern that we always see, right? Infectious diseases track along social fault lines. They exploit inequities within our social structure and target the people that are most vulnerable. ” The challenge of anonymity, coupled with difficulty in getting test results to confirm exposure, raises the possibility that it’s too late for a true ring strategy in the US.
But that doesn’t mean scarce doses cannot be targeted more precisely, given better data. A project launching next month aims to improve that situation, by gathering information not about who is being exposed, but where. RESPND-MI (for Rapid Epidemiologic Study of Prevalence, Network, and Demographics of Monkeypox Infection) is a queer-led investigation of the social epidemiology of monkeypox, created by Keletso Makofane, an activist and fellow at Harvard’s François-Xavier Bagnoud Center for Health and Human Rights.
(Osmundson is also involved; so is the HIV organization Prep4All. ) The group plans to launch an app-based, anonymous survey to create digital maps of sexual connections: asking people to identify locations where men who have sex with men, regardless of how they identify, are having the kinds of anonymous encounters that defeat traditional contact tracing. “There’s a mental map that people who work in HIV have of hot spots—where people have sex, or meet up in a way that makes connections to transmit pathogens—and I had the sense that this mental map is out of date,” Makofane says.
“So the idea for me was to update our understanding, in order to make intelligent decisions about where to place limited vaccines. ” Their goal is to produce data, down to the level of census tracts, that could be handed to health departments to influence vaccine distribution. That would not be ring vaccination; Makofane, like others, thinks the monkeypox epidemic has passed the point where ring vaccination is a sufficient response.
But vaccination could still be targeted, giving a community a voice in directing its own protection—which, during the wait for more vaccines and better testing, might be the most efficient and sensitive protection. The alternative, once those millions of vaccine doses arrive, might be ring vaccination’s traditional opposite: mass vaccination, to a certain degree. That could include not only men who have sex with men—and their partners—but also people who live where close contact is likely and hygiene is difficult: homeless shelters, for example, or prisons.
(In the 2000s, in the peak years of community-associated MRSA—also not a sexually transmitted disease, but also passed by close skin-to-skin contact—that pathogen spread in jails, and to jail guards’ families, and among pro athletes and everyday gym-goers. ) That would dispense with the need for tracing, or even suspecting, transmission, and would replace it with the assumption that anyone who wants protection should be allowed to access it. “If I had unlimited supplies of vaccine and unlimited money, I’d vaccinate every gay man I could, anyone who is sexually active and has sex with men,” Gonsalves says.
“I would start vaccinating people in homeless shelters. I’d vaccinate health care workers and lab workers. I’d try to do the broadest kind of outreach to the gay community, and then think about the next potential leap.
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From: wired
URL: https://www.wired.com/story/ring-vaccination-beat-smallpox-could-it-work-for-monkeypox/
