Smallpox inarguably shaped the course of human history by killing countless millions in both the Old World and the New World. Dr. Edward Jenner's discovery of vaccination in the late 18th century, and the global eradication of smallpox in the 1970s, rank among the greatest achievements in human history. Amidst recent growing concerns about bioterrorism, smallpox vaccination has resurfaced from the history books to become a topic of major importance. Inoculation with vaccinia virus is highly effective for the prevention of smallpox infection, but it is associated with several known side effects that range from mild and self-limited to severe and life-threatening. As the United States moves forward with plans to vaccinate selected health care workers and the military, and perhaps offer the vaccination to all citizens in the future, it is important to fully understand and appreciate the history, risks, and benefits of smallpox vaccination.

Background: A rise in absenteeism among healthcare workers (HCWs) was recorded during the COVID-19 pandemic, mostly attributed to SARS-CoV-2 infections. However, evidence suggests that COVID-19 vaccine-related side effects may have also contributed to absenteeism during this period. This study aimed to synthesize the evidence on the prevalence of absenteeism related to COVID-19 vaccine side effects among HCWs. Methods: The inclusion criteria for this review were original quantitative studies of any design, written in English, that addressed absenteeism related to the side effects of COVID-19 vaccines among HCWs. Four databases (PubMed, Scopus, Embase, and the Web of Science) were searched for eligible articles on 7 June 2024. The risk of bias was assessed using the Newcastle–Ottawa scale. Narrative synthesis and a meta-analysis were used to synthesize the evidence. Results: Nineteen observational studies with 96,786 participants were included. The pooled prevalence of absenteeism related to COVID-19 vaccine side effects was 17% (95% CI: 13–20%), while 83% (95% CI: 80–87%) of the vaccination events did not lead in any absenteeism. Study design, sex, vaccination dose, region, and vaccine type were identified as significant sources of heterogeneity. Conclusions: A non-negligible proportion of HCWs were absent from work after reporting side effects of the COVID-19 vaccine. Various demographic factors should be considered in future vaccination schedules for HCWs to potentially decrease the burden of absenteeism related to vaccine side effects. As most studies included self-reported questionnaire data, our results may be limited due to a recall bias. Other: The protocol of the study was preregistered in the PROSPERO database (CRD42024552517).

<h4>Background</h4>Although the respiratory syncytial virus (RSV) membrane protein F has become one of the major target proteins for RSV vaccine development, previous studies have identified safety issues with RSV vaccines in older adults. The causes of these issues remain unclear.<h4>Objective</h4>We aimed to evaluate the safety and efficacy of a novel RSV preF vaccine in preventing lower respiratory tract infections (LRTIs) and RSV-associated acute respiratory illnesses (RSV-ARIs) in older adults.<h4>Methods</h4>We conducted a systematic review of randomized controlled trials from 5 databases-PubMed, Embase, the Cochrane Library, Web of Science, and the Cochrane Central Register of Randomized Controlled Trials-published up to July 31, 2024. For categorical variables, we used the risk ratio; for continuous variables, we used the weighted mean difference or standardized mean difference. We extracted key study characteristics and assessed their quality using the Newcastle-Ottawa Scale. Sensitivity analyses were used to evaluate the impact of individual studies on pooled effects, and publication bias was examined with Egger and Begg tests.<h4>Results</h4>Meta-analysis of 5 studies (101,825 older adults) showed a reduced LRTI incidence in the vaccinated group, with heterogeneity resolved after excluding 1 study. Analysis of 4 studies (99,931 participants) confirmed a lower RSV-ARI incidence with no heterogeneity. Safety analysis (14 studies, 76,695 participants) showed higher adverse events (AEs) in the vaccinated group, mainly injection-site reactions and vaccine-related AEs, but no significant difference in serious AEs. Subgroup analyses identified potential sources of AE heterogeneity, and sensitivity analyses confirmed the efficacy but suggested variability in the injection-site reactions. .<h4>Conclusions</h4>This meta-analysis showed a statistically significant difference in the incidence of LRTI and RSV-ARI between the vaccine and placebo groups in older adults. However, no significant differences were observed in overall AEs or serious AEs.

On 22 February 2024, the World Health Organization (WHO) stated that, following the recent resurgence of measles cases in Europe, more than half the world's countries could expect significant measles outbreaks this year. Measles is a highly infectious virus with a primary case reproduction number (R0) of 12-18. Measles infection can be severe, resulting in pneumonia, and also more rarely in subacute sclerosing panencephalitis (SSPE), which occurs in 1 child out of every 1,000 and can be fatal. Until the 1990s, the hope of eliminating measles seemed possible following the successful development of effective vaccines, given individually or in the combined measles, mumps, and rubella (MMR) vaccine. Vaccine hesitancy due to misinformation about possible vaccine side effects, reduced vaccine uptake during and after the COVID-19 pandemic, and lack of awareness of the severe consequences of measles infection have contributed to low vaccine uptake, resulting in vulnerable communities. This article aims to review the recent resurgence of measles cases in the US, Europe, and the UK, to provide a reminder of the potential severity of measles, and to consider the causes of the failure to eliminate this vaccine-preventable viral infection.

vaccine are available in stockpiles. First and second-generation vaccines contain live unattenuated vaccinia virus and can cause serious side effects The smallpox vaccine is used to prevent smallpox infection caused by the variola virus. It is the first vaccine to have been developed against a contagious disease. In 1796, British physician Edward Jenner demonstrated that an infection with the relatively mild cowpox virus conferred immunity against the deadly smallpox virus. Cowpox served as a natural vaccine until the modern smallpox vaccine em The first-generation vaccines are manufactured by growing…

Vaccine hesitancy (VH) for childhood immunizations has been widely studied, but no review has synthesized evidence across Europe. This review addresses that gap using both qualitative and quantitative perspectives. A systematic search on February 5th, 2025, was conducted in MEDLINE/PubMed and Web of Science to assess the generalizability of findings regarding parental VH regarding childhood vaccinations (excluding HPV and Influenza) across the WHO European Regions. Forty-nine articles published between January 2015 and December 2024 in English, Dutch or French were included. Using WHO's 3C model (confidence, convenience, complacency), trust in healthcare professionals (HCPs) emerged as a key factor, while fear of side effects, logistical barriers and low perceived disease risk negatively influenced decisions. Demographic determinants were not generalizable across countries due to methodological and contextual (cultural, socioeconomic and healthcare system) differences, reinforcing the need for tailored approaches. VH remains multidimensional and context-dependent. WHO's 3C model is a useful tool for understanding VH. Tailored, country-specific strategies are needed, with strong HCP - caregiver relationships and policies addressing practical and socioeconomic barriers to ensure equitable access to childhood vaccination.

that smallpox and vaccine are probably the same disease, the virus of which is modified and its virulence lessened by passing through the body of the