Health system decision-makers need evidence on how modifiable factors contribute to inequalities to inform effective interventions. We examined ethnic group and deprivation inequalities in influenza and COVID-19 hospitalizations in England (2023–2024) among vaccine-eligible individuals, using causal mediation analysis to assess the roles of deprivation, vaccination uptake and comorbidities. For influenza, hospitalization odds were highest among Pakistani and Bangladeshi groups, compared with White British individuals. Deprivation mediated 26% of the total ethnic group effect for the Pakistani group and 41% for the Bangladeshi group, whilst comorbidities contributed little. Ethnic group differences in COVID-19 hospitalizations were minimal in this post-pandemic period. For both infections, the most deprived group had disproportionately high hospitalization compared to the least deprived. For influenza, vaccination uptake mediated 17%–26% of deprivation effects, whilst for COVID-19, there were no meaningful residual deprivation inequalities after including vaccination uptake and comorbidities. Vaccination uptake and deprivation mediate a substantial proportion of inequalities in hospitalization for influenza and COVID-19 in the vaccine-eligible cohort. Improving vaccination coverage in under-vaccinated groups should remain a public health priority.

In 2017–2018, New South Wales (NSW), Australia, experienced a hepatitis A virus (HAV) outbreak predominantly affecting men who have sex with men (MSM). We aimed to estimate immunity and identify immunity gaps among MSM in NSW. We triangulated four data sources. We tested 409 residual sera collected from males undergoing syphilis testing between August and October 2017 for anti-HAV IgG. We surveyed all publicly funded sexual health clinics about HAV testing and vaccine provision for the preceding financial year. We conducted a convenience behavioural survey of 50 men at a sex-on-premises venue in October 2017, and we analysed community survey data from 2018 to 2019 (n = 5,924). Descriptive statistics and logistic regression ere used to examine associations with immunity and vaccination. Overall serological immunity was 62.8% (257/409) and increased with age, from 50.0% in those aged under 26 years to 79.0% in those over 45 years. Clinic immunity and community survey estimates were higher (74.5% and 76.8%). Immunity gaps were identified among bisexual men, those less connected to the gay community, and people born outside Australia. NSW Health implemented targeted vaccination and community engagement in response. Multisource assessment provided actionable evidence to guide targeted vaccination and outbreak response.

Observational vaccine effectiveness (VE) studies provide essential real-world evidence but are prone to bias. Valid synthesis relies on rigorous risk-of-bias (RoB) assessment in systematic reviews of VE studies. Following JBI guidance, we mapped and described RoB assessment methodologies in systematic reviews of VE studies. We searched MEDLINE, Embase, and Web of Science from 1 January 2013 to 17 May 2023 and the grey literature from 1 January 2018 to 15 August 2023. Of 367 identified reviews, 38 lacked any RoB assessment, yielding 203 systematic reviews. Of these, 190 used existing tools (NOS (85/190, 44.7%), ROBINS-I (46/190, 24.2%), and JBI (11/190, 5.8%)) and 13 used an author-developed tool (13/203, 6.4%). Tools were adapted in 16.7% (34/203) of reviews and 7.2% (14/203) used multiple tools. Reviews included 20 (±25.7) observational studies, commonly cohorts (175/203, 86.2%), with COVID-19 (66/203, 32.5%) and seasonal influenza (62/203, 30.5%) frequently studied. VE was reported descriptively in 25.1% (51/203) of reviews, while 74.9% (152/203) provided meta-analyzed estimates primarily based on laboratory-confirmed infection (137/203, 67.5%) and symptomatic disease (130/203, 64.0%). Our findings indicate heterogeneous RoB assessment, reflected by use of different/multiple tools, frequent adaptations, author-developed methods, and absence of RoB assessment, highlighting the need for clearer guidance or tailored tools.

This article examines the evolution of COVID-19 vaccination efforts during 2021 and 2022 in six Central American countries, each with distinct social policy legacies and political regimes. Drawing on official data sources, the article differentiates two phases: the initial rollout of vaccines and the subsequent expansion of second-dose coverage to secure immunity. We advance three main arguments. First, differences in performance can be partly explained by the state capacities needed to implement vaccination campaigns. Second, regime type does not explain success; Nicaragua matched the performance of the most effective democratic countries. Third, presidential will accounts for the divergent trajectories of autocratic regimes. These findings underscore that in times of crisis, effective social intervention is possible without democratic pressures and accountability and highlight the need to further examine variation within nondemocratic regimes.

What are the determinants of individual uptake of vaccination? Using original data from a survey fielded in September 2021 in Germany and the United Kingdom, this study looks at the impact of three factors on individual vaccination during the COVID-19 pandemic. In a first study using observational data, we look at individual trust in institutions and political ideology. In a second study, based on experimental data, we assess the impact restrictions for unvaccinated individuals in the form of ‘green pass’ policies have on the propensity to get vaccinated.

Results from the first study show that trust in institutions and ideology are associated with vaccination uptake. Results from the survey experiment indicate that the ‘green pass’ policy scenario significantly increased willingness to get a booster shot for Germans, but not for UK respondents, due to a ceiling effect in the United Kingdom.

We further ask whether the effects of trust and policy coercion ‘amplify’ or ‘compensate’ each other. We find that trust has a ‘compensation’ effect, whereby individuals not yet vaccinated are considerably more likely to do so if they trust political institutions. Trust also compensates for other policy measures, as trusting individuals are highly likely to get vaccinated with or without the ‘green pass’ policy incentive, whereas low-trust individuals are more likely under the ‘green pass’ scenario.

Through emerging interpretations of individual “medical freedoms,” a panoply of state legislative bills seeks to undermine long-standing public health and health care requirements including recommendations to test, screen, treat, and vaccinate persons. To the extent these bills could upend decades of laws and policies protecting individual and communal health, especially among vulnerable individuals, they threaten the health — and freedoms — of all persons.

Fluctuations in disease severity occurred throughout the COVID-19 pandemic in England due to emerging variants and changing population immunity. Deaths caused by COVID-19 reduced from 2022; however, a smaller reduction was observed in deaths following a COVID-19 test. This study examines whether mortality risk within 28 days of a positive SARS-CoV-2 test remained elevated during a period of reduced disease severity. National-level routinely collected health data containing SARS-CoV-2 test results, vaccination, hospital, and death records were linked to create a population-level cohort. Individuals testing positive and negative were matched on demographic and disease characteristics. Mortality risk was compared using univariable and multivariable conditional logistic regression models for the overall time-period (March 2020–April 2022) and the focus time-period (January–April 2022). Individuals testing positive in the overall time-period had a 228% increased risk of death than those testing negative. In the focused time-period, test positive individuals had 63% higher odds of death, accounting for vaccination and previous hospitalisation. The increased risk of death associated with testing positive was greater among unvaccinated individuals (238%) than vaccinated individuals (155%). Mortality risk following COVID-19 remained elevated at the end of the pandemic, especially among unvaccinated individuals, supporting continued COVID-19 booster vaccination campaigns.

Occupational blood exposure accidents (OBEAs) pose significant risks to healthcare workers, potentially exposing them to hepatitis B (HBV), hepatitis C (HCV), and HIV. While most research focuses on hospital settings, this study assessed OBEA management in non-hospital contexts. Although our data predate the COVID pandemic, findings remain highly relevant, especially for healthcare professionals working outside hospital settings. A retrospective analysis of OBEA registry data (2006–2014) was conducted in a southern Dutch region. Data included demographics, profession, workplace, injury type, source status (HBV, HCV, HIV), risk assessment, post-exposure measures, and lab results. Chi-square and t-tests were applied. In total, 975 OBEA were reported. Among nurses, medical assistants, students, and housekeeping staff, subcutaneous needles (51–67%) and lancets (25%) were common exposure sources. Police officers mainly reported biting (26%), scratching, or spitting (70%). HBV vaccination coverage ranged from 18% (housekeeping) to over 90% (nurses, police). Post-exposure measures were taken in 52% of cases. High-risk exposures (43%) mainly affected ambulance staff, sterilization workers, police, and dentists. Sources were tested in 85% of high-risk cases: 1.4% were HBV positive, 2% HCV positive, and 1.1% HIV positive. No seroconversions occurred. Results stress the need for better HBV vaccination coverage, targeted prevention, and prompt OBEA reporting outside hospital settings.

This article examines the historical transformation of childhood vaccination in the Netherlands between 1872 and 1959. It analyses how vaccination was reframed from an individual parental responsibility to a collective practice through the establishment of the ‘Rijksvaccinatieprogramma’ (National Immunisation Programme). I analyse this historical trajectory as a case of ‘public health atomism’, a strategy that achieves collective health by prioritizing individual health outcomes and local action. Rather than relying on top-down state mandates, the ‘Rijksvaccinatieprogramma’ was a consequence of co-operation between general practitioners, municipal health officials, civil society organisations, and volunteers. Drawing from published medical sources, parliamentary records, and material from local and national archives, this article provides a detailed historical account of how local governance and autonomy shaped vaccination practices, highlighting the role of the ‘entgemeenschap’ (vaccination community) as a key organisational model for situated collaboration. As such, it revisits childhood vaccination as an archetypical example of biopolitical state intervention, demonstrating how localised, flexible co-operation was instrumental in integrating vaccination into Dutch society.

This study aimed to evaluate the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and inactivated virus vaccination on intracytoplasmic sperm injection (ICSI) outcomes in infertile couples. A retrospective case–control study was conducted at the Royan Institute from August 2020 to March 2022. The study included 90 couples in the COVID-19 infection phase and 31 in the vaccination phase. A total of 30 infected but unvaccinated couples were compared to a control group of 60 couples with no COVID-19 infection or vaccination history. Additionally, 31 couples underwent treatment before and after receiving the Sinopharm inactivated vaccine. Key variables analysed included sperm parameters (concentration, motility, progressive motility and morphology), ovarian parameters (antral follicle count, oocyte retrieval), embryological outcomes and pregnancy outcomes. SARS-CoV-2 infection significantly reduced sperm motility (P = 0.02) and progressive motility (P = 0.01) compared to controls. Sperm concentration and morphology showed non-significant declines. Post-vaccination analysis revealed similar but statistically insignificant changes in sperm parameters. Ovarian stimulation parameters and embryological outcomes remained unaffected by both infection and vaccination. Although biochemical, clinical pregnancy and live birth rates were lower among the infected group, these differences did not reach statistical significance (p = 0.16, 0.08 and 0.09). SARS-CoV-2 infection has been associated with impaired sperm progressive motility, which may negatively influence ICSI outcomes. In contrast, vaccination with an inactivated virus does not appear to impact fertility outcomes. These findings provide crucial guidance for physicians and infertile couples managing treatments during and after the pandemic, suggesting the need for extended recovery periods before ART procedures following COVID-19 infection.

In this article, I examine the history of the concept of herd immunity, beginning with British epidemiologists in the 1920s and ending with the controversy surrounding it during the COVID-19 pandemic. I argue that competing historical and contemporary understandings of herd immunity reveal an underlying tension between observing the effects of infection-acquired herd immunity on the population dynamics of infectious diseases and actively cultivating it through immunisation. Originally offering an explanatory mechanism for the rise and fall of epidemics, the concept soon became entangled with strategies of disease control and technologies for producing immunity, particularly as mass vaccination became more common in the postwar era. This tension between observing herd immunity and cultivating it has produced diverse interpretations ranging from the temporary abatement of an outbreak due to the accumulation of infection-acquired immunity to the principle undergirding disease elimination through mass vaccination. I close by suggesting that the scientific debates and uncertainties regarding the relevance of herd immunity to public health strategies during the COVID-19 pandemic reflect this long-running tension between observing and cultivating immunity in populations.

The Secretary of the US Department of Health & Human Services, Robert Kennedy Jr is leading a political agenda against vaccination. This is undermining the delivery of life-saving vaccination programmes and provision of evidence-based information on the safety and effectiveness of vaccines for the public and health professionals. Inconsistent and conflicting messaging between health practitioners and government health agencies erodes trust in public health programmes, creating a vacuum which is often filled with mis/disinformation that presents severe consequences for families. Due to the transnational spread of diseases, we consider the implications of events in the US for routine childhood vaccination programmes in the UK. Public health agencies across the world need to be ‘Kennedy ready’; pragmatic steps must be taken to mitigate threats posed to vaccine confidence and the control of vaccine preventable diseases.