About The Study: In this cohort study, recent COVID-19 vaccination was associated with a reduced risk of SARS-CoV-2 transmission. These findings suggest that COVID-19 vaccination may have an indirect benefit of decreasing transmission and thus reducing overall exposure to SARS-CoV-2.

Researchers at Georgetown’s Lombardi Comprehensive Cancer Center have identified a mechanism that may help explain a key reason why older people experience worse outcomes from breast cancer. A key aspect of the study benefited from timing and chance. During COVID, because of reduced laboratory activity, some of the research team’s mouse colonies aged longer than originally planned. This created a rare opportunity to study cancer in these older animals, which is normally a difficult and expensive endeavor. Serendipitously, the opportunity gave the scientists the ability to directly compare how tumors behave in younger versus older mice.

(Boston)—Superspreading became a familiar concept to many during the COVID-19 pandemic. Prior studies examining infectious disease epidemics, including those on COVID-19, have found that some individuals are much more likely to transmit infections to other people. Superspreading, when one person with an infection passes it to an unusually large number of other people, is a key feature of tuberculosis (TB) epidemiology. Most individuals with TB, the disease caused by infection with Mycobacterium tuberculosis, cause very few secondary infections, and often cause no secondary infections at all. However, many studies, including groundbreaking studies in the 1950s and 1960s examining TB transmission observed that some individuals with TB are more highly infectious and cause many more secondary infections among their contacts. As a result, the overall impact on future transmission of diagnosing someone with TB and treating them with antibiotics (typically making them non-infectious within 1-2 weeks) can vary widely from person to person.

In a new perspective piece in The Lancet Infectious Diseases, researchers from Boston University Chobanian & Avedisian and the University of Colorado Anschutz School of Medicine examine both historical and contemporary evidence in M. tuberculosis superspreading. They argue it represents not only a critical challenge for global TB control, but also a potential opportunity for innovative prevention strategies. The authors introduce the idea of "superspreading niches", specific parts of community contact networks where highly infectious individuals intersect with highly susceptible contacts, as a key framework for understanding TB superspreading and designing new TB control interventions.

Tracking the genetic diversity of SARS-CoV-2 in wastewater, rather than just viral abundance, dramatically improves the ability to monitor and predict COVID-19 outbreaks, researchers report. Their study suggests that the new approach to wastewater pathogen surveillance could serve as a powerful predictive tool for public health, providing earlier and more accurate insight into emerging waves of infection. Monitoring pathogens in wastewater has become a powerful public health tool since the COVID-19 pandemic, offering a fast, cost-efficient, and potentially less biased way to track infectious diseases across scales. Because wastewater collects biological material from an entire population, a single sample can provide a broad snapshot of community-wide infection dynamics. Yet the standard methods used to estimate disease prevalence, which rely on measuring the amount of viral genetic material recovered from a given volume of wastewater, are vulnerable to limitations. Some measurements cannot be meaningfully compared across different pathogens or settings, while others are easily distorted by environmental factors like rainfall. According to Dustin Hill and colleagues, analyzing pathogen genetic diversity through whole-genome sequencing has the potential to overcome several of the limitations of traditional wastewater surveillance methods. They argue that changes in viral genetic diversity itself may serve as a meaningful indicator of shifts in disease spread within a population.

 

Here, Hill et al. introduce and validate a method for estimating the prevalence of SARS-CoV-2 by analyzing the virus’s genetic diversity in wastewater. To evaluate this idea, Hill et al. retroactively applied and analyzed genetic diversity within SARS-CoV-2 from 12,290 wastewater samples collected between 2023 and 2025 from across New York state. They found that genetic diversity within a specific region of the viruses’ spike protein – the S1 NTD region – closely tracked real-world COVID-19 infection trends and, in many cases, correlated with disease activity more strongly than traditional wastewater metrics. Moreover, the authors’ statistical analyses revealed that diversity patterns in wastewater consistently preceded increases in COVID-related hospital admissions by one to two weeks, suggesting robust early warning signals of worsening disease spread. “The use of wastewater surveillance as a primary tool for monitoring population health is still a developing area,” write Justin Lessle and Ariel Christensen in a related Perspective. “Nevertheless, [this approach] has the potential to revolutionize infectious disease research and public health practice. Viral sequencing approaches such as that proposed by Hill et al. will be an important component of that success.”

Neurological diseases are an increasing public health challenge in China. A recent meta-analysis of 12 disorders shows a rising overall burden, with intracerebral hemorrhage as the leading cause and dementia as the fastest-growing condition. Several disorders rose sharply between 2019 and 2021, coinciding with the onset of the COVID-19 pandemic. These findings indicate shifting disease patterns and highlight the need for improved prevention, early detection, and long-term care strategies nationwide.

A detailed analysis of airflow in a Spanish high-rise found a COVID-19 outbreak likely spread via the bathroom ventilation system. The findings have implications for other airborne diseases and for older multi-family buildings around the world.

Research from the University of Bath (UK) finds depression and anxiety remain high yet overlooked among around 1.8 million clinically vulnerable people in the UK still living restricted lives to avoid Covid.

A study conducted by researchers at University of Tsukuba revealed that individuals with higher cancer-related health literacy, perceived susceptibility to gastric cancer, and encouragement from family members or healthcare providers demonstrated stronger intentions to undergo gastric cancer screening, even during the COVID-19 pandemic. These intentions were significantly associated with subsequent screening participation. In contrast, while fear of COVID-19 increased screening intention in the short term, over time it could suppress screening behavior.

Telemedicine has not significantly increased visits and medical spending across all payer types, which could ease concerns among lawmakers that the telemedicine expansion that occurred during the COVID pandemic would result in large utilization and spending increases.

New research from the University of Kansas shows a “risk gene” linked to higher odds of developing autoimmune diseases such as diabetes or lupus may also provide a survival advantage fighting viral infections like coronavirus. The research centers on a gene called PTPN22, which carries a mutation, 1858C>T (R620W), found in roughly one in 10 people in North America.

A new study in JAMA Network Open found that between 1999-2022, the annual number of excess US deaths—deaths that would not have occurred had the mortality rate in the US been the same as in other HICs—increased steadily through 2019 and then rose rapidly during the COVID-19 pandemic. By 2022, all-cause mortality rates in the US were 38 percent higher than in other HICs. An estimated 12.7 million US deaths could have been averted during this period if US mortality rates mirrored those of its peers. The authors refer to these excess US deaths as “missing Americans.”

A new study explored whether women visualised a vaccine would have a positive or negative impact on their babies, and if that affected their decision to be vaccinated. The findings, published in the journal Social Science & Medicine, showed that mental images were common and – depending on whether that mental image was a positive or negative one, and about the impacts of diseases or the vaccine itself – could be used in some cases to predict if and when the women ultimately became vaccinated during pregnancy.

An early estimate of COVID-19 vaccine effectiveness for the 2025/26 season in Canada found that the vaccine had a protective effect even in the context of mismatched lineages.