| |
U.S. at risk of mpox surge even worse than last year, CDC modelers warn
|
| |
| |
The CDC estimates that just 23% of the "at-risk population" for mpox, like men who have sex with men and people with multiple sex partners, have been fully vaccinated. Vaccination rates are in the single digits across many states.
The figure on this page shows vaccine coverage by jurisdiction for the estimated population at risk for mpox in people who have had at least one dose and who are fully vaccinated. CDC estimates show that without continued efforts to vaccinate people with the highest risk of mpox exposure, including newly sexually active gay, bisexual, and other men who have sex with men (MSM), a resurgence of mpox will become more likely over time.
During the current multinational outbreak, U.S. 1- and 2-dose vaccination coverage reached an estimated 37% and 23%, respectively, among persons at risk, with wide variation among jurisdictions. The predominant administration route switched from subcutaneous to intradermal after the week of August 20, 2022, in accordance with Food and Drug Administration recommendations.
What are the implications for public health practice?
Despite administration of >1 million vaccine doses, only 23% of the at-risk population has been fully vaccinated. Targeted outreach and continued access to and availability of mpox vaccines to persons at risk is important to help prevent and minimize the impact of a resurgence of mpox.
--------------------------------
CDC: Risk Assessment of Mpox Resurgence and Vaccination Considerations
Updated March 30, 2023
Implications
The risk of mpox resurgence in the United States warrants continued efforts to vaccinate people who are most likely to be exposed to mpox, including MSM who have had more than one sexual partner in the last six months and other risk groups outlined in the U.S. National Mpox Vaccination Strategy.[ix] Outreach, education, and other public health interventions among affected populations, including the young and newly sexually active, could help improve vaccination targeting and other response measures.
Summary
The 2022 mpox outbreak in the United States has receded to very low levels. However, most jurisdictions in the United States may be at risk of resurgence or new mpox outbreaks without continued efforts to vaccinate people at risk, based on new modeling analyses. The chance of an outbreak and its predicted size will likely increase over time without continued efforts to vaccinate people at highest risk of mpox exposure.
Background
The 2022 mpox outbreak in the United States has slowed to about one case per day, down from a peak of about 460 cases per day on average in early August 2022.[i] The outbreak has likely slowed because of a combination of vaccination, infection-induced immunity, and temporary changes in sexual behavior.[ii],[iii] In this assessment, we explore the risk of resurgent mpox outbreaks at the jurisdiction level.
Assessment
If mpox reintroduction occurs and no additional vaccination or sexual behavior adaptations occur, the risk of a resurgent mpox outbreak is greater than 35% in most jurisdictions in the United States. Resurgent outbreaks in these communities could be as large or larger than the 2022 outbreak. This is because immunity is relatively low in populations who are highly affected, including sexually active men who have sex with men (MSM) in these jurisdictions. In jurisdictions where immunity is higher in these populations, the risk is anticipated to be low over the next year, although a renewed outbreak could occur. These jurisdictions include most jurisdictions that had large mpox outbreaks in 2022, such as California, the District of Columbia (DC), Illinois, and New York.
We have moderate confidence[1] in our assessment, which is based on the epidemiologic characteristics of mpox,[iv] estimates of vaccine coverage in jurisdictions across the United States (JYNNEOS Vaccine Coverage by Jurisdiction | Mpox | Poxvirus | CDC), and a simulation model[iii][v] exploring potential mpox resurgence in DC following the cessation of the outbreak (CDC, unpublished), with results extrapolated to other jurisdictions. Our model showed:
• The risk of a resurgent mpox outbreak across U.S. jurisdictions is ongoing, should new infections enter from other areas or countries.
• The chance of a new outbreak and its predicted size will grow over time as new, never-vaccinated or never-infected people become sexually active, reducing overall population immunity.
• In jurisdictions with high levels of vaccination coverage (>75%), and therefore population immunity, the risk of a renewed mpox outbreak is 5%–12% each year over the next five years if mpox reintroduction occurs. Outbreaks could average only <15% of the 2022 outbreak size, even in the absence of additional vaccination or sexual behavior adaptations after an outbreak emerges (Figure 1).
• In jurisdictions with low levels of vaccination coverage (<35%) with at least one dose (JYNNEOS Vaccine Coverage by Jurisdiction | Mpox | Poxvirus | CDC), which includes most U.S. jurisdictions, resurgent outbreaks are more likely (>35% risk of occurring given reintroduction). Outbreaks could be as large or larger than the 2022 outbreak if no additional vaccination or sexual behavior adaptations take place (Figure 1).
• If the vaccine was not administered to those with higher sexual activity and thus greater likelihood of exposure in 2022, resurgent outbreaks are probably even more likely.
Another factor that could increase the risk of mpox resurgence in the United States is the degree of waning immunity. Monkeypox virus infection and vaccination are likely to confer some immune protection for years, based on evidence from smallpox disease and vaccination.[vi] However, if this protection wanes quickly or does not effectively stop transmission of the virus, resurgent outbreaks would be more likely. Mutations to the virus could also increase the risk of mpox resurgence if they caused it to spread more readily or evade prior immunity. We believe this risk is low, however, given the relatively limited number of cases in the United States and globally, and relatively slow evolution of the virus.[vii],[viii]
https://www.cdc.gov/poxvirus/mpox/response/2022/risk-assessment-of-resurgence.html
------------------------
U.S. at risk of mpox surge even worse than last year, CDC modelers warn
March 30, 2023 / 9:08 PM / CBS News
The U.S. could see a renewed surge of mpox infections even worse than last year, new federal modeling has concluded, based on data showing most American communities remain far short of vaccination rates needed to fend off outbreaks in at-risk groups.
With "moderate confidence," the CDC's modelers said in a report published Thursday that most parts of the country have a "greater than 35%" risk of mpox, formerly known as monkeypox, resurging over the coming months.
"It's not us saying get more people vaccinated because we think it's a good idea. We need to get more people vaccinated because we know there's a linear relationship between how many people are vaccinated and the chance of not having an outbreak," Dr. Demetre Daskalakis, deputy coordinator for the White House's mpox response, told CBS News on Thursday.
The CDC estimates that just 23% of the "at-risk population" for mpox, like men who have sex with men and people with multiple sex partners, have been fully vaccinated. Vaccination rates are in the single digits across many states.
Authorities are now ramping up outreach ahead of the return of travel, and events in the warmer months could fuel the renewed spread of the virus, alongside other sexually transmitted infections.
"This is the time to do that little health check, that tune-up before we get into summer to make sure that we have all our ducks in a row," said Daskalakis.
He pointed to a new webpage created by the agency that embeds the mpox vaccine locator alongside other information, like travel warnings and a locator for getting HIV pre-exposure prophylaxis. Instead of pop-up clinics manned by health departments, many sexual health clinics are now offering Jynneos doses.
"This is getting embedded into the fabric that we do to prevent sexually transmitted infections, like HIV. So it's moved back into a space that's more routine," said Daskalakis.
Cases of mpox have so far slowed nationwide, according to the CDC's tally, down from a peak of more than 450 infections per day in August. Today,only around one case per day is reported on average around the country and only a handful of jurisdictions have spotted mpox in their recent wastewater surveillance.
Data suggests the rollout of Jynneos vaccine doses last year blunted the risk of mpox last year after the first shot, with bigger reductions in risk after getting the second.
However, other factors likely played a role in the outbreak slowing last year. New mpox infections had already begun to dip before the rollout of the two-dose Jynneos vaccine. Countries that did not deploy any doses at all also saw slowdowns in infections.
"That first sort of deflection down I think had to do with the fact that we, not just CDC and federal public health, but the community really mobilized itself to make changes in behavior to be able to reduce transmission," said Daskalakis.
The CDC's modelers also think people who survived mpox infections will likely have some protection from reinfection for years, similar to people who survived a related virus: smallpox. But the risk of reinfection could climb as time passes, as well as if the virus mutates to evade immunity.
At the height of mpox spreading last year, authorities had raised concern when some people were infected by strains that had evolved a "significant deletion" which evaded some tests.
"Now when the cases are down, this is when it helps to try to get people vaccinated so we can prevent the outbreaks," said Daskalakis.
For people who had already gotten both doses of vaccine, Daskalakis said that he thinks they will still have that "sort of level 10 force field, the best we can get." But he also acknowledged officials are continuing to study the issue.
https://www.cbsnews.com/news/mpox-risk-us-surge-worse-2022-cdc-warns/
|
|
| |
| |
|
|
|
