“I think we’re going to have to live with it until they vaccinate every high-risk person,” Dr. Robert Murphy, executive director of the Havey Institute for Global Health at the Northwestern University Feinberg School of Medicine, said this week.
Vaccinating someone already exposed to monkeypox to help prevent illness is called post-exposure prophylaxis or a ring vaccination strategy. Vaccinating a patient’s close circle of contacts is like vaccinating a “ring” around them.
This approach has been used in response to sexually transmitted infections and prior monkeypox outbreaks.
“We can have a really effective strategy of containment and elimination by identifying all the cases and then providing the cases with treatment and the close contacts of those cases with post-exposure prophylaxis,” said a federal health adviser who requested anonymity because they’re not a government employee and don’t speak for any federal agency.
“We know that this works,” the adviser said. “We have data from other outbreaks to say that it is effective. And so in the beginning, when cases were low — in the tens, the dozens of cases — we were able to effectively work with jurisdictions to identify those cases and, through consultation, figure out how many doses of vaccines would they need to vaccinate as many contacts as they think existed.”
But toward late June, the monkeypox outbreak had spread.
The CDC’s initial strategy “was just doomed to failure,” Murphy said, referencing how a “ring” strategy requires swift and robust outreach to all known contacts of a monkeypox patient — which was becoming increasingly difficult to do as cases were growing, and in more places.
“A ring vaccination strategy was never going to work, frankly,” Murphy said. “I mean, look how fast this virus has spread.”
“We recognized that a traditional post-exposure prophylaxis strategy was no longer the best strategy for that current moment of the outbreak — and so we shifted, along with the nation,” the federal health adviser said.
As of Friday, the US has tallied nearly 5,200 confirmed or probable monkeypox cases. With limited supply and growing awareness of the virus and its painful effects, vaccination appointments are still going fast.
Limitations of the ring strategy
Even though the US response to the monkeypox outbreak has evolved, there are clear reasons why federal health officials would immediately consider a ring vaccination strategy early on.
But Adalja and many other public health experts argue that a broader vaccination response against monkeypox should have been implemented from the beginning, as the ring strategy comes with a limitation: It hinges on robust contact tracing.
“Because of the unique characteristics of this outbreak — the fact that it’s spreading mostly amongst men who have sex with men and has been kind of exploiting anonymous sex parties, raves and the like — it became quickly clear that contact tracing was going to miss a lot of contacts, especially if individual case patients didn’t even know the names of their contacts,” Adalja said.
“It’s not that we don’t have the contact tracers. It’s that the individuals don’t know their contacts,” he said. “The contact trace data was not complete enough to be able to rely solely on ring vaccination.”
For ring vaccination to work, “there has to be enough vaccine, those in the ring need to be identified and vaccinated, and this has to be done quickly,” Dr. Tom Frieden, former CDC director and president and CEO of Resolve to Save Lives, wrote in an email to CNN.
“Because many contacts of cases were from anonymous encounters, this makes ring vaccination much more challenging,” he wrote. “And because monkeypox is spread by intimate contact, identifying those who were close to the patients is much harder than for smallpox, both because of the sensitivity of this information, and because some of the contacts may have been anonymous.”
CDC spokesperson Kristen Nordlund told CNN that “ring vaccination can only be effective if all contacts of a case are identified and vaccinated.”
“As the outbreak went on, it became clear that some of the cases were having anonymous close encounters, which fueled transmission. CDC then expanded our vaccination strategy,” she wrote in an email.
The federal health adviser said this is not unique to monkeypox.
“Ring vaccination requires identification of cases and identification of contacts, and that is challenging no matter what disease it is. It’s challenging for Covid; it’s challenging for HIV; it’s challenging for syphilis,” the adviser said. “And so just because it’s challenging doesn’t mean we didn’t want to pursue this strategy.”
‘We went against CDC’
Some local health officials saw the writing on the wall early in the outbreak and never implemented a ring vaccination of just close contacts. Instead, vaccines have been offered to a broader group of higher-risk people from the beginning.
In the nation’s capital, the DC Department of Health has been closely tracking the spread of monkeypox virus since the spring, watching anxiously as cases emerged in regions of the world where the virus typically is not seen.
When the first US case was reported in Massachusetts, DC health officials organized a team that was trained in identifying monkeypox and how it spreads. Around that time, the city also ordered vaccines.
Among the close contacts, “we actually have vaccinated 246 people in that first ring,” Mangla said Wednesday. “When I broaden that net, we have vaccinated — as of last night — 6,628.”
He added that if DC just focused on vaccinating the close contacts in ring one, those thousands of people who voluntarily got immunized in ring two would have received the vaccine much later during the outbreak.
“We went against CDC,” Mangla said of the district’s broad two-ring vaccination approach, adding that the CDC is now working on projects with the DC Department of Health to better understand this outbreak response model.
However, the monkeypox vaccine supply has not met the growing demand in DC — or in most regions across the country.
The public health community “is recognizing the tension between our desires and limited supply,” the federal health adviser said.
With limited supply, cities prioritize first doses
“This decision is based on the available scientific evidence, the acceleration of the outbreak, the demand for vaccine from the high number of eligible people, and extreme shortages of the JYNNEOS Monkeypox vaccine nationally,” the announcement said. “DC Health is confident that additional vaccine doses will be available when needed for those who have received their first dose.”
In New York City, which also expanded eligibility for the monkeypox vaccine to any adult in a high-risk group, first doses have been prioritized.
Chicago also is prioritizing first doses of vaccine.
These vaccines are being offered through doctors’ offices and clinics as well as pop-up events at venues, such as bathhouses and Pride events, according to the city’s announcement.
“The goal is address equity along with maximizing doses administered,” Massimo Pacilli, the Chicago Public Health Department’s deputy commissioner of disease control, wrote in an email.
“This is a national model that has been developed by the Centers for Disease Control and Prevention and it is consistent with our neighboring jurisdictions,” Department of Public Health Commissioner Dr. Manisha Juthani said. “DPH is partnering with 15 community-based clinics to expand the availability and efficient delivery of the vaccine to those who need it the most.”
A ‘rapidly closing’ window
Still, questions remain around where the nation’s fight against monkeypox is heading.
“It’s not clear that monkeypox can be contained at this point, but it’s certainly worth trying,” said Frieden, the former CDC director.
Federal health officials remain optimistic that the nation can end the outbreak.
“To the question, can we not only stay ahead of this virus but end this outbreak? Absolutely,” Becerra said Thursday.
“We believe that we have done everything we can at the federal level to work with our state and local partners and communities affected to make sure we can stay ahead of this and end this outbreak, but everybody’s got to take the oar and row. Everybody’s got to do their part.”
Lawrence Gostin, faculty director of the O’Neill Institute for National and Global Health Law at Georgetown University, said “the window for containing monkeypox is rapidly closing.”
“I do think it’s still possible to contain, but it’s also equally possible that this may become endemic in the United States,” he said.
To contain the monkeypox virus, Gostin called for the United States to declare a national public health emergency, raise awareness about the virus in non-stigmatizing ways and, of course, make more vaccine doses available.
“We continue to monitor the response throughout the country on monkeypox,” Becerra said Thursday. “We will weigh the decision on declaring a public health emergency based on the response we’re seeing throughout the country.”