Yesterday, a CDC panel discussed whether smallpox vaccines should be offered more widely as a preventive measure against monkeypox. The panel made no decision. But getting those shots into patients’ arms—and particularly gay and bisexual men’s arms—is an urgent matter. Since May 13, more than 3,300 cases of monkeypox have been reported in 58 countries where the disease was not previously thought to be endemic, including the United States. The CDC is reporting at least 172 cases. Before this outbreak, monkeypox had usually been reported from West and Central Africa, or in travelers from those regions. The new cases are occurring on all inhabited continents, mainly among men who have sex with men (MSM).
The U.S. is underreacting to the monkeypox outbreak. Given that a vaccine is available for the infection—and can be targeted toward the people most at risk—public-health authorities and health-care providers need to move more quickly and forcefully to change the outbreak’s trajectory.
Monkeypox is related to smallpox, the only human virus that has been eradicated worldwide. A highly effective smallpox vaccine, called Jynneos, has been licensed in the United States for use against monkeypox as well. Data from Africa suggest that it is at least 85 percent effective in preventing the latter condition.
On June 1, the CDC updated its recommendations to say that Jynneos is the preferred post-exposure prophylaxis for health-care workers and others who have had close contact with monkeypox patients. The U.S. has about 36,000 doses in its stockpile and expects 300,000 additional doses in coming weeks. It needs to purchase many more—and should offer the vaccine to all MSM at risk of exposure in the next month. Canada just signed a $56 million deal with the manufacturer of the Jynneos vaccine, and Quebec has started offering the vaccine to all MSM. The U.K. is expanding its vaccination campaign as of this week to offer shots to the gay and bisexual men at highest risk of exposure. The New York City Health Department announced the opening yesterday of a clinic in Chelsea that will offer the vaccine to MSM who have had multiple partners in the past 14 days.
When the coronavirus spread worldwide in early 2020, we lacked an effective vaccine, so governments required masks, distancing, ventilation, testing, and contact tracing to try to minimize transmission until the COVID-19 shots arrived. The world is not at the same disadvantage with monkeypox; we have a vaccine, and our current attempts to test and contact trace our way out of this epidemic are failing. A swift, targeted vaccination campaign—one that identifies Americans at risk and persuades them to get a shot—is far more likely to stop the monkeypox outbreak.
Different diseases require different responses. The coronavirus is becoming endemic because it spreads quickly and easily, and even high-quality vaccines that protect against severe disease do not prevent initial infection or reinfection. Smallpox, among the most deadly pathogens in history, could be eliminated because of four distinguishing features that most human pathogens do not have: Its symptoms—most notably, the skin rash it causes—are very characteristic, so doctors could easily identify patients who had it; its infectious period was short; new infections were preventable by a highly effective vaccine; and the virus had no animal reservoirs from which it could infect unvaccinated humans. As such, routine smallpox vaccinations for U.S. populations were stopped in 1972. Yet because of the cessation of mass vaccination programs for smallpox, humans have waning protection from monkeypox.
The name monkeypox comes from the first documented cases of the illness in animals in 1958, when two outbreaks occurred in monkeys being used for research. However, the infection until recently was usually spread by rodents such as rats, mice, and squirrels, and transmitted to humans by a bite from an infected animal, or by touching an infected animal’s blood, body fluids, or fur. A 2003 outbreak among humans in the U.S. was traced to pet prairie dogs infected by a shipment of mammals from Ghana.
Many of the current cases are in MSM ages 30 to 55, at first linked to two large raves held in Spain and Belgium. Of note, sexual transmission of monkeypox has never previously been described. Although monkeypox has been reported in semen, the most likely route of spread during the current outbreak is the close skin-to-skin and respiratory contact during sexual activity. Moreover, transmission from prolonged face-to-face contact can put household members and other close contacts of active cases at greater risk.
That monkeypox is spreading among gay men has led to calls to postpone this month’s Pride celebrations, and the CDC has faced some criticism for recent messaging that offers tips on how to avoid the pathogen during sex. Yet the agencies are following the well-grounded concept of harm reduction—which calls for both minimizing the impact of a health threat while also recognizing the other needs of the individuals and society involved. People crave companionship and intimacy, and messages that ignore those needs and recommend complete abstinence are unlikely to succeed. Harm reduction is the basis of most current public-health messaging about reducing HIV risk, and is profoundly important in the field of addiction and substance use.
Health agencies deserve credit for trying to minimize stigma in their communication, even as they recognize that relevant communities need to be alerted to how this particular outbreak is being spread. (The WHO is also considering a change in the very name monkeypox to prevent stigma against the geographic areas originally connected with the disease and to banish associations with animals that appear to play little role in its spread.)
Stopping the monkeypox outbreak in the U.S. isn’t enough. The WHO is scheduled to meet today to decide whether to declare monkeypox a global health emergency—a move that clinicians from Africa argue is long overdue. Although the virus is not a significant threat to the general population, as COVID-19 was, declaring a global health emergency will raise awareness of both this outbreak and endemic infections. As the World Health Organization has previously pointed out, rich countries have ignored endemic monkeypox in West and Central Africa for far too long, despite having effective vaccines, which should be equitably distributed to the populations at risk worldwide. The crucial point is that all these efforts should be happening right now. We have to stop underreacting to the world’s latest infectious-disease threat.