Background: Vaccination constitutes a low-cost, safe, and efficient public health measure that can help prevent the spread of infectious diseases and benefit the community. The fact that vaccination effectiveness varies among populations, and that the causes of this are still unclear, indicates that several factors are involved and should be thoroughly examined. The “intestinal microbiota” is the most crucial of these elements. Numerous clinical studies demonstrate the intestinal microbiota’s significance in determining the alleged “immunogenicity” and efficacy of vaccines. This systematic review aimed to review all relevant scientific literature and highlight the role of intestinal microbiota in COVID-19, Salmonella typhi, Vibrio cholerae, and rotavirus vaccinations. Materials and Methods: The MESH terms “vaccines” and “microbiota” were used to search the major scientific databases PubMed, SciVerse Scopus, Web of Knowledge, and the Cochrane Central Register of Controlled Clinical Trials. Results: Between February 2024 and October 2024, the analysis was conducted using electronic databases, yielding a total of 235 references. Finally, 24 RCTs were chosen after meeting all inclusion criteria: eight studies of COVID-19, two studies of Salmonella typhi, three studies of Vibrio cholerae, and eleven studies of rotavirus. Only six of these demonstrated good study quality with a Jadad score of three or four. Conclusions: According to the review’s results, the intestinal microbiota surely plays a role in vaccinations’ enhanced immunogenicity, especially in younger people. As it is still unclear what mechanisms underlie this effect, more research is needed to better understand the role of the intestinal microbiota.

In Italy, cervical cancer represents the fifth most prevalent cancer in women under 50 years of age and is one of the most commonly detected lesions globally. Given the developing burden of the disease and the availability of both primary and secondary prevention measures, their accurate surveillance is of paramount importance. The aim of this study was to evaluate the trends in cervical cancer screening adherence in the period between 2020 and 2022, as well as to evaluate positive tests, identifying the most frequently associated genotypes and the vaccination coverage. The study sample was made up of 6880 women from the health district of Messina. We highlighted that there was a high proportion of positive results in the investigated period, with a high prevalence of HSIL. Moreover, HPV vaccination coverage was clearly inadequate, as was adherence to screening, both far away from WHO goals. This finding is probably linked to inadequate communication and awareness of the issue in the population and to the lack of data relating to tests carried out privately. In accordance with existing data in the literature, the introduction of the HPV-DNA test in Sicily made it possible to identify women positive for the genotypes most frequently involved in the etiopathogenesis of neoplastic lesions (genotypes 16 and 18), as well as for those in the “others” category, which should be investigated because some of them could have an impact on carcinogenicity and, for this reason, a future vaccine including them could represent a new prevention weapon.