Obesity accelerates the loss of COVID-19 vaccine-induced neutralizing antibody capacity, concludes a University of Cambridge study published yesterday in Nature Medicine.

The researchers used the Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 platform to evaluate the relationship between body mass index (BMI) and infection-related hospitalization and death among 3.6 million adults in Scotland. Participants had received a second primary vaccine dose or a first booster dose of Pfizer/BioNTech or AstraZeneca/Oxford vaccine from December 8, 2020, to March 19, 2022. 

People with obesity are known to be at elevated risk of poor COVID-19 outcomes and to have weaker immune responses to vaccines against flu, rabies, and hepatitis, the researchers noted.

Frequent booster doses likely needed

Participants with severe obesity (BMI greater than 40 kilograms per square meter [kg/m²]) were at a 76% higher risk of COVID-related hospitalization or death (adjusted rate ratio, 1.76). Infections after the second vaccine dose also led to hospitalization and death starting at 10 weeks among people with severe obesity and 15 weeks among those with milder obesity, compared with 20 weeks among healthy-weight participants.

A longitudinal analysis comparing 28 severely obese people with 41 controls who had a healthy BMI (18.5 to 24.9 kg/m²) showed that the SARS-CoV-2 neutralizing antibody capacity of 55% of severely obese participants was too low to measure, compared with 12% of those with a healthy BMI 6 months after the second vaccine dose—even though they had similar antibody levels.

More frequent booster doses are likely to be needed to maintain protection against COVID-19 in people with obesity.

Regardless of antibody level, people with severe obesity had lower neutralizing capacity than those with a healthy BMI. A third COVID-19 vaccine dose restored neutralizing capacity but was followed by more rapid waning in severely obese than in healthy-BMI participants.

"More frequent booster doses are likely to be needed to maintain protection against COVID-19 in people with obesity," coauthor Sadaf Farooqi, MBBS, PhD, said in a University of Cambridge news release. "Because of the high prevalence of obesity across the globe, this poses a major challenge for health services."

Today in Morbidity and Mortality Weekly Report, two unrelated cases of Trichophyton indotineae infections are described, suggesting the severe, antifungal-resistant tinea is now being locally transmitted in the United States.

The skin infection, caused by dermatophyte molds, has become an epidemic in South Asia, because T indotineae infections are highly transmissible, and resistant to commonly used antifungal and steroid creams. T indotineae isolates are frequently resistant to terbinafine, a mainstay of tinea treatment, the authors said, but the skin condition had previously only been seen in Asia and Europe

The report describes patients seen by a New York City dermatologist who notified health officials in February of severe tinea that did not improve with oral terbinafine treatment, raising concern for potential T indotineae infection. The patients shared no epidemiologic links.

Health care providers should consider T. indotineae infection in patients with widespread tinea.

The first patient was a pregnant woman with no travel history, suggesting she picked up the infection locally. The second patient, also a woman, had recently traveled to Bangladesh.

Both women presented with widespread large, annular, scaly, itchy plaques over the neck, abdomen, pubic region, thighs, and buttocks. After the terbinafine failure, subsequent therapies healed the first woman, but the second woman had only about 80% improvement and is still being treated by the dermatologist.

"Health care providers should consider T. indotineae infection in patients with widespread tinea, particularly when eruptions do not improve with first-line topical antifungal agents or oral terbinafine," the authors wrote.

European countries are reporting an increase in Escherichia coli isolates carrying the blaNDM-5 gene that makes them resistant to carbapenems, a class of antibiotics that are often used as a last resort to treat serious E coli infections, according to a report yesterday from the European Centre for Disease Prevention and Control (ECDC).

Preliminary data from 36 European countries in 2019 had shown that NDM (New Delhi metallo-beta-lactamase)-5 had become the most frequently reported carbapenemase in E coli isolates. The aim of the new study was to determine the extent of the spread of the resistance gene in E coli in the European Union/European Economic Area (EU/EEA).

European researchers analyzed whole-genome sequencing and epidemiologic data on 874 E coli isolates from the national collections of 13 countries and confirmed the increase of E coli isolates carrying blaNDM-5, finding it in 83 different sequence types (STs). They note, "The high number and the large size of multi-country clusters in the dataset, including recent isolates from 2022, suggest an ongoing rapid global expansion of these dominant E. coli STs carrying blaNDM-5, including the EU/EEA."

Links to travel common

They also found that 84.2% of patients infected with E coli isolates carrying blaNDM-5 had links to a country outside of Europe, mainly in Africa and Asia. "This suggests that travel-related acquisition may still be the most likely origin of these isolates," the author write.

There is a risk that the number of cases of carbapenem-resistant E. coli infections will increase in the EU/EEA.

An ECDC news release on the report says, "E. coli carrying blaNDM-5 are spreading rapidly and on a large geographical scale, and there is a risk that the number of cases of carbapenem-resistant E. coli infections will increase in the EU/EEA within a few years."

A Eurosurveillance study of the data, also published yesterday, notes that 30.6% of the NDM-5 isolates were associated with infections, and 58.2% were predicted to be multidrug-resistant.