First HPV vaccine recipients see 80% drop in cervical precancer incidence

News brief

Almost 20 years have passed since the US recommended the human papillomavirus (HPV) vaccine to prevent cancers and other diseases caused by HPV, and a new study shows a major drop in precancer incidence among women who were most likely to have been vaccine recipients.

In a new study in Morbidity and Mortality Weekly Report, the authors say the first recipients of the vaccine have now been screened for cervical cancer, and precancer incidence has decreased 80% among screened women aged 20 to 24 years.

The study describes trends in incidence of precancerous lesions tracked by the Centers for Disease Control and Prevention (CDC) from 2008 through 2022. During that period, rates among women aged 20 to 24 decreased by 79% to 89%, while rates among women aged 25 to 29 years old decreased by 37%.

Vaccination before sex initiation most effective

"The data are consistent with a considerable impact from the U.S. HPV vaccination program on cervical precancers, with the largest decreases in the youngest age group for which benefit of vaccination would first be observed," the authors wrote.

The data are consistent with a considerable impact from the U.S. HPV vaccination program on cervical precancers.

During 2018 to 2022, all women aged 20 to 24 years would have been eligible for vaccination at the routine age—11 or 12 years—in 2006, the authors said. Vaccination at that age is more effective because it precedes exposure to HPV through sexual contact.

"Although some women in age groups 30–34 years and older would have been vaccinated, less impact is expected among women in this age group at this time because they were only eligible for catch-up vaccination, at ages when many women are already sexually experienced and therefore likely to have been infected with HPV," the authors noted.

Avian flu was in Oregon wastewater weeks before state's first bird outbreaks, study shows

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Mary Van Beusekom, MS

Duck floating on water — *LHG Creative Photography / Flickr cc*

A retrospective analysis reveals that H5 avian flu surfaced in Oregon wastewater weeks before the state's first outbreak in poultry and wild birds and 2 years before the first outbreak in US cattle.

A team led by Oregon State University researchers evaluated 551 influenza A virus–positive wastewater samples from 20 sites from September 2021 to July 2024.

In January 2022, H5N1 clade 2.3.4.4b virus was first identified in wild birds in the United States. In Oregon, the clade was first detected in wild birds and poultry in May 2022.

"Interpretation of avian influenza A(H5) subtype detections in wastewater requires an understanding of human and animal contributors to the sewershed because current testing does not distinguish between human and animal sources," the authors wrote. "Potential animal contributors include wild birds, farms with poultry or dairy cattle outbreaks, and dairy processing facilities."

The results were published in Morbidity and Mortality Weekly Report.

Wild birds the likely culprit

Of the 551 influenza A–positive samples, 21 (3.8%) tested positive for H5 in 12 communities 6 weeks before Oregon's first outbreak in domestic poultry, 7 weeks before the first detection in wild birds, and 2 years before the first outbreak in US dairy cattle (the virus hasn't been found in cattle or milk in Oregon).

Wastewater surveillance, with consideration of all animal contributors and in conjunction with other surveillance metrics, has the potential to strengthen ongoing avian influenza surveillance efforts.

"No association was found between detection of avian influenza A(H5) in a community’s wastewater and history of an HPAI A(H5) outbreak among poultry in the county or presence of dairy processing facilities or dairy farms within the sewershed," the researchers wrote.

Avian flu was found most often in two communities with important wild bird habitats, which the authors said implicates wild birds as a significant contributor to wastewater H5 contamination.

"Oregon is located along the Pacific Flyway, a major north-south route for migratory birds in the Americas that extends from Alaska to Patagonia," the authors wrote. "Wastewater surveillance, with consideration of all animal contributors and in conjunction with other surveillance metrics, has the potential to strengthen ongoing avian influenza surveillance efforts."

Trial data show Rebyota is safe, effective in immune-compromised patients with recurrent C diff

News brief

Chris Dall, MA

Clostridioides difficile — Jennifer Oosthuizen / CDC

A subgroup analysis of data from a phase 3 clinical trial found that a fecal microbiota–based treatment for recurrent Clostridioides difficile infection (rCDI) was safe and effective in participants with mild-to-moderate immunocompromising conditions, researchers reported yesterday in Open Forum Infectious Diseases.

The data were from PUNCH-CD3-OLS, an open-label, prospective, single-arm study designed to evaluate the safety and tolerability of the fecal microbiota–based live therapeutic Rebyota (RBL) in a "real-world" population of rCDI patients. Rebyota was approved by the US Food and Drug Administration for preventing rCDI in adults following standard-of-care antibiotic treatment based on the results of the trial and other clinical trial data. But a 2024 clinical practice guideline noted that there was insufficient evidence to recommend RBL in mild or moderately immunocompromised adults with rCDI and recommended against its use in severely immunocompromised patients, owing to concerns about increased risk of infection.

Safety, efficacy results are similar across participants

For the study, a team led by researchers from Beth Israel Deaconess Medical Center in Boston analyzed treatment-emergent adverse events (TEAEs) and efficacy outcomes in 141 of 697 trial participants who received RBL and had immunocompromising conditions or were taking immunosuppressive medications. TEAEs within 8 weeks of treatment were reported by 44.7% of immunocompromised participants and 48% of non-immunocompromised patients. Most events were mild or moderate gastrointestinal disorders.

Serious TEAEs within 8 weeks were reported by 4.3% and 3.8% of immunocompromised and non-immunocompromised participants, respectively. But no RBL-related systemic infections occurred.

In immunocompromised participants, the treatment success rate at 8 weeks was 75.7% and the sustained clinical response rate at 6 months was 88.7%, similar to results in the non-immunocompromised subgroup (73.3% and 91.6%, respectively).

The study authors say the safety and efficacy results in immunocompromised patients are consistent with those from previous studies in the RBL clinical trial program.

"This analysis provides important data regarding the safety and efficacy of RBL for rCDI in mildly to moderately immunocompromised patients, which can assist clinical decision-making in real-world care settings," they wrote.