Respiratory syncytial virus (RSV) is a leading cause of hospitalisation in infants worldwide. New immunoprophylactic products, including long-acting monoclonal antibodies and maternal vaccines, have demonstrated high efficacy in prelicensure clinical trials. Understanding how these interventions perform outside controlled trials, and how viral evolution or host factors influence protection, is essential for sustaining confidence in RSV prevention programmes.

We will conduct a 5-year, test-negative case–control study among infants ≤12 months of age who present with acute respiratory illness (ARI) within a large healthcare delivery network serving a demographically diverse population. Cases will be infants testing positive for RSV by PCR, and controls will be RSV-negative infants meeting the same ARI criteria. Data will be obtained from electronic health records, structured caregiver surveys and state immunization registries to ensure accurate classification of exposures and covariates. Vaccine effectiveness will be estimated using multivariable logistic regression controlling for potential confounding. RSV-positive specimens will undergo full-genome sequencing to identify variant lineages and potential immune-escape mutations. A subset of participants will provide acute and convalescent blood samples for single-cell immune profiling to define innate and adaptive responses associated with breakthrough infection.

The study protocol has been approved by the Yale Human Investigation Committee (HIC #2000036550). Written informed consent will be obtained from all parents or legal guardians prior to participation. Study findings will be disseminated through peer-reviewed publications, scientific meetings and public repositories, with fully de-identified participant data to protect privacy and confidentiality. Viral genomic data will be shared in accordance with the National Institutes of Health Genomic Data Sharing Policy, and analytical code will be made publicly available to ensure reproducibility.

NCT06172660.

During 2009–2018, the Emory Global Health Institute conducted the Tobacco-Free Cities (TFC) programme in 22 cities in mainland China. This study aims to assess the sustained impact of the TFC programme.

A qualitative study using semi-structured interviews was adopted, which focused on the leadership and capacity building, city-level smoke-free policies, tobacco control activities, outcomes of tobacco control, sustainability post TFC programme and the accomplishments of tobacco control. The thematic analysis was employed for qualitative data analysis.

Online in-depth personal interviews.

This qualitative study recruited 17 participants from 10 cities which participated in the TFC programme (five with comprehensive and five with partial smoke-free policies). Interview participants included TFC programme leaders, TFC staff and current tobacco control staff.

First, TFC members reported enhanced competencies in smoke-free policy effort and leadership. Five cities with comprehensive smoke-free policies had a high degree of public support, while cities with partial bans faced barriers such as lack of leadership support and experiencing tobacco industry influence. Tobacco control activities, including media campaigns, policy enforcement, cessation programmes and monitoring activities, were sustained in almost all cities. Enhancement in smoke-free social norms, decrease in smoking rate and second-hand smoking exposure were perceived. Challenges to sustainability included reduced financial and personnel resources and weakened policy enforcement.

The TFC programme was regarded by participants as an effective model that provided the necessary training and technical support to develop and enforce effective and sustainable tobacco control policies and initiatives at the city level in China. Future tobacco control training should focus more on developing concrete solutions for sustainability challenges.