The mpox vaccine appears to offer long-term protection amid growing concern over outbreaks of a particularly virulent strain of mpox in Central Africa and an increase in cases in the United States since early last year. The Centers for Disease Control and Prevention Thursday.
in Separate ReportThe CDC noted that the number of new MPOX infections across the United States has remained stable and low in recent months. At the peak of the epidemic in summer 2022, there were 3,000 new cases per week, but now the number is around 60 per week. However, the number of infections so far this year has increased nationwide compared to the same period in 2023, and is also rapidly increasing in New York City.
According to the CDC, people who have received two doses of the Jynneos mpox vaccine are protected against infection and do not need a booster dose at this time.
Public health experts say the start of the summer travel season and LGBTQ Pride festivals in cities across the country could lead to more sexual connections among gay and bisexual men, potentially speeding the spread of MPOX. I am concerned that there is.
Christina Hutson, head of the CDC’s Poxvirus and Rabies Branch, and other public health experts told NBC News that it’s not time to get complacent about mpox (previously known as monkeypox) because of a variety of factors — including the virus — that seem to have kept its spread relatively contained in the U.S. since late 2022. vaccination, Infection-induced immunityand Changes in sexual behavior — may be tenuous.
Dr. Jeffrey Klausner, an infectious disease expert at the University of Southern California, said mpox outbreaks are “poised to occur again if the right conditions are right.” The infectious disease rapidly spread across the world starting in May 2022, and that summer was a harrowing time for many gay and bisexual men.
Importantly, the proportion of at-risk gay and bisexual men in the United States who are fully vaccinated with the mpox vaccine is low enough to protect this vulnerable population in the long term. considered insufficient.
“Vaccination is a critically important way to protect yourself and others,” Hutson said. “It is important that anyone who is at risk for MPOX infection and has not previously recovered from MPOX, particularly gay, bisexual, and men who have sex with men, complete the two-dose series of the Jynneos vaccine.”
On May 16th, CDC releases disturbing report About 20,000 recent cases have been linked to what is known as MPOX lineage 1. documented In the Democratic Republic of Congo (DRC) from January 2023.
Concerningly, this virus clade appears to be more transmissible and associated with higher rates of severe disease and mortality compared to clade 2 of mpox, which caused the recent pandemic. In the DRC, 5 percent of those diagnosed with clade 1 have died, while in the Democratic Republic of Congo, only 0.2 percent of the 96,000 people have died. Global occurrence of clade 2.
So far, no lineage 1 cases have been reported outside of some African countries where MPOX has been endemic for decades. In December, CDC first warned Health care workers realized that this more harmful group of viruses could hit the United States.
“We’re facing a huge potentially dangerous situation, but we don’t really know,” said Ira Longini, a biostatistician at the University of Florida, regarding the potential global spread of clade 1. he said.
Dr. Bogma Titanji, assistant professor of medicine at Emory University School of Medicine, suggested that the Jynneos vaccine likely provides protection against clade 1. Jynneos vaccine is approved In the United States, mpox is used regardless of clade.
“It’s reasonable to expect that there will be some degree of immune cross-protection” from immunity derived from both the vaccine and previous clade 2 infection, he said.
Clinical trials of the Jinneos vaccine in progress Among health workers in the Democratic Republic of Congo, it is not expected to be completed before the end of next year.
However, the vaccine has not been distributed in the Democratic Republic of the Congo, leading to a missed opportunity to curb the domestic outbreak and prevent lineage 1 from spreading globally, Titanzi said.
Dr Placido Mbala, head of epidemiology and global health at the University of Kinshasa in the Democratic Republic of Congo, said his country was seeing “huge interest” from global public health leaders in providing such support. .
“But we are still waiting for concrete action,” Mbala said.
During clade 2 outbreaks, MPOX was predominant by sexual intercourse, Both oral and anal, between men. Transgender people too Disproportionately affectedThe virus is not easily transmitted through the air or surface, In the medical fieldor through casual, Non-sexual contact.
In an interview earlier this year, CDC epidemiologist Dr. Jennifer McQuiston said MPOX “needs to be thought of as a sexually transmitted disease. The good news is that it’s a preventable sexually transmitted disease.”
Multiple studies of Recruitment in the real world of ginneos vaccine Two doses of the vaccine have been shown to reduce infection rates by 66% to 89%, while one dose has been suggested to be 36% to 75% effective.
in One of the new CDC reportsAgency investigators analyzed demographic data and clinical characteristics for 271 MPOX cases from the beginning of the U.S. outbreak in May 2022 through May 2024 among fully vaccinated people in 27 U.S. jurisdictions that provided sufficient relevant data.
According to CDC officials, the agency estimates that only 0.1% of the fully vaccinated population has developed a breakthrough infection. Such cases reported represent 0.8% of the 32,819 people diagnosed with MPOX nationwide, and 13% of MPOX cases were in partially vaccinated people.
The CDC estimates that 2 million men in the United States are at significant risk for MPOX because they have sex with multiple male partners or are HIV positive. The rate of MPOX diagnosis among HIV-infected women is high. Only about 25% of all at-risk gay and bisexual men have been fully vaccinated, and an additional 14% have received one Jynneos shot.
in storage and previous researcha new report from the CDC found that full vaccination is associated with reduced severity of illness and lower rates of hospitalization.
All 56 MPOX deaths were in unvaccinated individuals.
recent research Have express concern The antibodies induced by Jinneos are said to weaken over time. But CDC investigators have found evidence that, at least so far, the vaccine’s actual protection against infection has not diminished. This is probably due to what is called innate immunity or cell-mediated immunity.
Shortly after the vaccine was first distributed in mid-summer 2022, U.S. health officials began augmenting temporarily scarce supplies by changing how the vaccine is administered from the traditional subcutaneous (under the skin) injection to an intradermal (intradermal) injection, which requires a much smaller dose.
The new CDC report found no evidence to support this. Vaccination transformation The effectiveness of the vaccine has decreased.
a New CDC analysis Recent MPOX diagnoses in the United States have found that the virus remains overwhelmingly prevalent among gay and bisexual men, with only 0.4% of recent cases occurring in people under the age of 18.
Between October and April, 42 jurisdictions reported 1,802 suspected and confirmed cases of MPOX to CDC, remaining roughly constant at an average of 59 cases per week. In contrast, at the peak of the outbreak from mid-July to late August 2022, the country was seeing between 2,000 and 3,300 cases per week.
nevertheless, According to CDC records: The approximately 750 MPOX cases confirmed by mid-April this year are more than double the number reported for the same period in 2023. new york city The incidence of infections increased almost fivefold between these two periods, with 191 cases occurring so far in 2024.
As for concerns about how a lineage 1 outbreak will play out in the United States, infectious disease experts can only speculate whether higher-quality health care will lead to lower mortality rates than in the Democratic Republic of the Congo, for example. said. Globally, most deaths from lineage 2 occur among people with weakened immune systems, primarily due to untreated HIV.
Other unknowns include how and among which groups clade 1 tends to be transmitted in Western countries. Outbreaks of DRC occur both in men with multiple male sex partners and in female sex workers and their contacts. And two-thirds of the clade 1 outbreaks in the DRC were in people under 16 years of age.Just over 1% Global lineage 2 outbreak I was a minor.
Epidemiologists have seen evidence of sustained person-to-person transmission in one province in the Democratic Republic of the Congo, primarily affecting adults.
This transmission is primarily sexual, but compared to MPOX lineage 2, lineage 1 shows signs of being easily transmitted without sexual activity. However, lineage 1 still appears to require close personal contact, and non-sexual transmission appears to be primarily restricted to the household environment. Additionally, a recent CDC report suggests that the high number of infections among children may be due in part to multiple escapes from wild animals encountered by young people in rural areas.
CDC officials say widespread transmission of clade 1 among children in the United States is unlikely due to a lack of animal holding space, less crowded living spaces, and improved cleaning and sanitation. I think it’s much lower.
Emory University’s Titanji said the gay and bisexual men he cares for quickly lost interest in getting the MPOX vaccine once the epidemic was no longer their top concern. reported that they were worried about In fall 2022, the domestic weekly distribution rate of the Jynneos vaccine plummeted in conjunction with the MPOX case rate.
since then, No real progress This was done to increase the proportion of at-risk gay and bi men who received both doses of Jynneos.
“If you haven’t gotten the vaccine yet and you meet the criteria, please go get vaccinated,” Titangzi said. “We can’t be complacent with how we’re handling this going forward.”
