The policy sequence examined in the study began with a change from the Centers for Disease Control and Prevention’s prior recommendation of universal hepatitis B vaccination at birth. In December 2025, the Advisory Committee on Immunization Practices recommended deferred vaccination for infants whose mothers did not have hepatitis B until the infants were at least two months old. In January 2026, the CDC switched to recommending a shared clinical decision-making approach for those infants.

The source said the recommendations had been challenged by professional medical societies and public health agencies, but their clinical effects were unclear. The study, published in Annals of Internal Medicine , assessed the projected effects of these strategies rather than measuring outcomes under the new policies. Researchers from Mass General Brigham used a Markov cohort state-transition model to follow a synthetic population across health states over time.

The model was built with published epidemiological data and validated by comparing its projections with real-world CDC estimates of pediatric hepatitis B infections. It followed 3.6 million people, representing one year of births in the United States, through the first 20 years of life. Vaccination was recommended in every scenario for infants whose mothers were known to be hepatitis B positive.

The shared clinical decision-making scenario assumed that 50% of infants whose mothers were hepatitis B negative would be vaccinated at two months of age or later. The delayed-vaccination scenario assessed vaccination beginning at two months or later, while the comparison strategy was universal vaccination at birth. Under universal birth vaccination, the model projected that 255 people in the birth cohort would have chronic hepatitis B infection by age 20.

The count rose to 303 under delayed vaccination and 467 under shared clinical decision-making. These differences corresponded to projected increases of 48 and 212 chronic infections, or approximately 19% and 83%, respectively, relative to vaccination at birth. The model also projected a large difference in susceptibility at age 20: approximately 232,000 people would remain susceptible under universal birth vaccination, compared with about 474,000 under delayed vaccination and 1.8 million under shared clinical decision-making.

The study therefore projected both more chronic infections and a larger pool of susceptible young adults under each alternative to vaccination at birth. The authors emphasized the clinical importance of the projected increase in adult susceptibility. They said hepatitis B infections acquired in adulthood have a higher likelihood of leading to life-threatening conditions, including acute liver failure, and noted that hepatitis B is also a common cause of liver cancer.

Amir Mohareb, the study’s corresponding author, said in the research news release that even a small increase in childhood infections could have large clinical, public health and economic effects. Because the analysis is a model projection based on published data and specified vaccination assumptions, it does not establish how many infections will actually occur or how the recommendations will affect individual families. Its findings remain conditional on the model’s assumptions, including the 50% vaccination rate assigned to the shared clinical decision-making scenario and the accuracy of the input epidemiological data.

Subject of Research: Modeled effects of US infant hepatitis B vaccination schedule changes on chronic infections and susceptibility through age 20.

Article Title: Changes to hepatitis B immunization schedule would increase infections, model predicts

Article References: Changes to hepatitis B immunization schedule would increase infections, model predicts. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: hepatitis B, HBV, infant vaccination, immunization schedule, cohort model, chronic infection, shared clinical decision-making, adult susceptibility, US births, public health, Changes, hepatitis

The scale of the funding immediately places the program in rare territory. Each Presidents’ Impact Scholar will receive $80,000 per year for four years, a package the university says is comparable to the most generous offers at top Ivy League institutions and, nationally, in a category of its own. That level of support matters for reasons that go beyond prestige. Doctoral students in Canada have long faced funding levels that push many talented candidates toward industry or toward universities abroad, and the new award is explicitly framed as a magnet for the best minds from Canada and around the world. The program is expected to become one of the most competitive PhD awards in the country, and the university argues it will function as a new model of doctoral education for the twenty-first century.

The structural innovation at the heart of the program is the annual theme. Each year, the university will select a significant societal challenge, a major question or vexing problem facing society, and recruit a cohort of twelve or more scholars based on their potential to advance meaningful work in that area. The theme changes annually, so each cohort forms a concentrated cluster of interdisciplinary talent around a distinct research frontier. The university offers a concrete illustration: a theme such as AI and Health could mobilize computer science, quantum computing, ethical and regulatory law, ethics and philosophy, social science, and AI safety and alignment in a sustained effort to address the multi-faceted challenge of designing, adopting and regulating artificial intelligence technologies in Canadian health care. Another example given is Sovereignty and the Arctic, a problem that similarly resists any single disciplinary lens.

Supervision is being redesigned along the same lines. Every scholar in the program will work with two faculty supervisors from different disciplines, a co-supervision structure intended to ensure that students develop the deep interdisciplinary expertise needed to catalyze advances in complex fields spanning multiple domains of knowledge. This is a meaningful departure from the traditional single-advisor model that still dominates doctoral training in most fields. The university’s argument is that the hardest contemporary problems, whether in biomedicine, climate, security or technology governance, do not respect departmental boundaries, and that the researchers best positioned to solve them are those trained from the outset to move fluently between ways of knowing.

Real-world engagement is the second pillar of the design. Presidents’ Impact Scholars will participate in an external engagement experience intended to enhance their capacity for practical problem-solving. That could take the form of a government partnership, an international placement, or an internship with industry partners doing relevant work. The program will also run extensive programming connecting each cohort with other researchers across the university, including graduate students, postdoctoral fellows and faculty members pursuing work related to the cohort’s theme. Engagement opportunities and support will flow through university communities such as U of T Entrepreneurship, signaling that the program treats commercialization and knowledge mobilization as legitimate and encouraged outcomes of doctoral research, not as distractions from it.

Selection criteria reflect this dual emphasis on scholarly excellence and practical impact. Candidates will be evaluated for academic excellence, but also for their track record in innovation and real-world problem-solving. The university notes that its scholars will be just as likely to be applied innovators committed to transforming brilliant ideas into meaningful public or commercial impact as they are to be outstanding scholars driving large-scale interdisciplinary research or shaping new paradigms of understanding in a specific field. In other words, the program is deliberately widening the definition of what a top doctoral candidate looks like, betting that curiosity, imagination and entrepreneurial daring are as predictive of future influence as conventional academic metrics.

University leadership has framed the initiative as a response to a changing world. President Melanie Woodin said that as Canada and the world face challenges of increasing complexity, future solutions will require new ideas and fresh thinking that cuts across disciplines, and she described the program as a major innovation in PhD education that will galvanize a new generation of thought leaders who will serve as key contributors to the prosperity of the country. Joshua Barker, dean of the School of Graduate Studies and vice-provost of graduate research and education, called the approach visionary, saying that Presidents’ Impact Scholars will benefit from a learning experience that sets a new standard for interdisciplinary, real-world problem-solving at the highest levels, and that they will be part of a cohort of exceptional peers working together on meaningful research and complex challenges, creating a collaborative community that enriches the doctoral experience.

Trevor Young, the university’s vice-president and provost, emphasized the systemic role doctoral students play in the research enterprise. PhD students, he said, are the backbone of the country’s research and innovation ecosystem, and through the program the university is making a generational investment in brilliant students from every conceivable discipline and background, empowering them to take on the biggest problems, including future challenges not yet known or understood. The university points to its doctoral legacy as context: students associated with Toronto have contributed to some of the biggest advances of the past century, from building the first electron microscope in North America to developing machine learning and deep neural networks. The new program, administrators suggest, opens a new chapter in that history, with the capacity to lift research across fields critical to Canada’s future, including artificial intelligence, quantum technologies, genomics, biomedical sciences, sustainability, public policy and cybersecurity.

The philanthropic story behind the program is itself notable. The enabling $50-million gift comes from a Canadian family foundation with a deep, long-standing history of support for the University of Toronto as well as other post-secondary institutions and research centres focused on encouraging innovative, multidisciplinary approaches to complex problems. The family wishes to remain anonymous. David Palmer, the university’s vice-president of advancement, said it is deeply gratifying to see the extraordinary investment and engagement of the philanthropic community with the university’s efforts to elevate and transform graduate education in Canada, describing the gift as an inspiring example of thoughtful philanthropy that raises institutional sights and transforms the collective potential to generate beneficial change for future generations. The university’s matching funds bring the total commitment to $100 million, and the endowment structure is intended to sustain the fellowship in perpetuity.

The launch also fits into a broader, coordinated push. Since 2024, working with philanthropic champions and public partners, the university has moved from a substantial graduate funding increase to a full suite of recruitment, recognition and research support programs for graduate students and postdoctoral scholars, and the new program builds directly on that momentum. Administrators argue the payoff could extend well beyond campus: by concentrating interdisciplinary talent on themes with clear national relevance, the program has the potential to advance knowledge mobilization in areas that strengthen and sustain Canada’s future prosperity and innovation while improving quality of life for communities across the country. A call for applications will be issued soon, and the inaugural cohort of Presidents’ Impact Scholars will begin their studies in September 2027. If the model works as designed, it could offer a template that other research-intensive universities, in Canada and abroad, will be pressed to imitate.

Subject of Research: A new interdisciplinary PhD scholarship program at the University of Toronto funded by a $100-million investment

Article Title: U of T transforms PhD education with launch of Presidents’ Impact Scholarship Program

Article References: U of T transforms PhD education with launch of Presidents’ Impact Scholarship Program. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: University of Toronto, PhD education, Presidents' Impact Scholarship, interdisciplinary research, doctoral funding, philanthropy, AI and health, knowledge mobilization, graduate education, research innovation, Canada, cohort model