Several studies have reported the waning effectiveness of COVID-19 vaccines. This study aims to demonstrate the applicability of the screening method for estimating vaccine effectiveness (VE) in a pandemic. We report VE in Hungary, estimated with the screening method, in 2021, covering a period of Alpha and the Delta variant, including the booster dose roll-out. Hungary is in a unique position to use six different vaccines in the same population. All vaccines provided a high level of protection initially, which declined over time. While the picture is different in each age group, the waning of immunity is apparent for all vaccines, especially in the younger age groups and the Sinopharm, Sputnik-V, and AstraZeneca vaccines, which performed similarly. This is clearly reversed by booster doses, more prominent for those three vaccines, where the decline in protection is more evident. Overall, two vaccines, Pfizer/BioNTech and Moderna, tend to produce the best results in all age groups, even with waning immunity considered. Using the screening method in future pandemic waves is worthwhile, especially in countries struggling with a lack of resources or when there is a need to deliver VE results within a short timeframe due to urgent decision-making.

There is a rich body of literature on the distribution of cancer incidence and mortality in socioeconomically different world regions, but none of the studies has compared the spatial distribution of mortality and incidence to see if they are consistent with each other. All malignant neoplasms combined and cervical, colorectal, breast, pancreatic, lung, and oral cancers separately were studied in the Hungarian population aged 25–64 years for 2007–2018 at the municipality level by sex. In each case, the spatial distribution of incidence and mortality were compared with each other and with the level of deprivation using disease mapping, spatial regression, risk analysis, and spatial scan statistics. A positive association between deprivation and mortality was found for each type of cancer, but there was no significant association for male colorectal cancer (relative risk (RR) 1.00; 95% credible interval (CI) 0.99–1.02), pancreatic cancer (RR: 1.01; 95%CI 0.98–1.04), and female colorectal cancer incidence (RR: 1.01; 95%CI 0.99–1.03), whereas a negative association for breast cancer (RR: 0.98; 95%CI 0.96–0.99) was found. Disease mapping analyses showed only partial overlap between areas of high incidence and mortality, often independent of deprivation. Our results highlight not only the diverse relationship between cancer burden and deprivation, but also the inconsistent relationship between cancer incidence and mortality, pointing to areas with populations that require special public health attention.

Hungary provides the opportunity to evaluate the effectiveness of COVID-19 vaccination in a setting where naturally acquired immunity and hybrid immunity are likely to play a greater role due to suboptimal vaccination coverage. Methods: A test-negative study was conducted during the 2022–2023 respiratory season at the primary care level to determine the effectiveness of at least one COVID-19 booster dose in preventing medically attended symptomatic RT-PCR-confirmed SARS-CoV-2 infection in adults. Unvaccinated patients were used as a reference group. Results: A total of 247 cases and 1073 controls were included in the analysis. CVE was 56.8% (95% CI: 11.9–78.8%) in the population aged 60 years and older and 2.3% (95% CI: −50.0–36.3%) in the younger adults against COVID-19 caused by Omicron subvariants, mainly BA.5, BQ.1, and XBB.1. Self-reported COVID-19 in the 60–365 days prior to the current illness did not confer protection against reinfection without vaccination, but together with booster vaccination, it reduced the risk of COVID-19 by 63.0% (95% CI: −28.0–89.3%) and 87.6% (95% CI: 26.4–97.9%) among the 18–59 and 60+ age groups, respectively. Conclusions: CVE against COVID-19 was moderately high in the 60+ age groups. Because of the benefit of hybrid immunity, persons with previous SARS-CoV-2 infection should still be considered for vaccination campaigns.

Background: Eastern Europe witnessed substantial life expectancy losses in 2021. COVID-19 vaccination coverage was lower, and mortality was higher than in Western Europe. Research suggests an important factor behind lower vaccination coverage is vaccine hesitancy. Our studies aimed to explore spatial inequalities in COVID-19 morbidity, mortality, and vaccination coverage in Hungary and the reasons behind vaccine hesitancy during the 3rd and 4th pandemic waves. Methods: We characterized COVID-19 morbidity, mortality, and vaccination coverage by indirectly standardized ratios at the municipality level and investigated the association with deprivation. Attitudes towards vaccination were measured by a nationally representative monthly questionnaire survey. Results: In Hungary, people in the most deprived municipalities had 17-58% higher relative COVID-19 mortality than the national average, although morbidity was significantly lower. COVID-19 vaccination coverage among the least deprived was 9.2% (95% CI 9-9.5%) higher, while in the most deprived areas, it was 38.2% (95% CI 38.0-38.4%) below the national average at the end of the 3rd pandemic wave. In the 10 districts with the highest proportion of the Roma population, vaccination coverage was 56.0% of the national average (95% CI 55.0-64.0%). Inequalities persisted by the end of the 4th pandemic wave. Younger age, lower education, and lower income were major determinants of vaccine refusal. Reasons for refusal mostly resulted from barriers to accessing reliable information and mistrust. Although Hungary has traditionally had high social acceptance of vaccination, the campaign failed to close the gap in COVID-19 mortality. Hungary demonstrates how social inequalities, misinformation, and mistrust can undermine a vaccination program's success. Consistent, credible communication can dispel misconceptions and build trust, which is key to the acceptance of public health measures.

COVID-19 vaccines reduce hospitalization risk, but data on severe outcomes are limited. We analyzed the impact of COVID-19 vaccination on severe outcomes in hospitalized patients in Hungary during the pre-Omicron era, addressing a regional knowledge gap. This retrospective study included hospitalized patients with PCR-confirmed COVID-19 (March 2020 - December 2021) who were categorized as unvaccinated, primary immunized, or booster-vaccinated. Outcomes included oxygen therapy, ventilation types, ECMO, and death, with the most severe outcome as the primary outcome and individual outcomes as secondary measures. Polytomous logistic regression calculated relative risk ratios for the primary outcome and COVID-19 vaccination status, while logistic regression estimated odds ratios for individual outcomes. During the study, 7575 patients were hospitalized with PCR-confirmed COVID-19: 6420 (84.8 %) were unvaccinated, 1016 (13.4 %) received a primary vaccination series, and 139 (1.8 %) had received a booster dose. COVID-19 vaccination reduced the risk of both invasive ventilation and in-hospital death as the most severe outcome by 50 % within 12 months (relative risk ratio [RRR]: 0.52, 95 % CI: 0.30-0.89; 0.50, 95 % CI: 0.41-0.61). Booster doses within six months decreased the risk of in-hospital death to a similar extent (RRR 0.46, 95 % CI: 0.30-0.72). Primary and booster vaccination reduced the risk of progression to severe outcomes in hospitalized COVID-19 patients.

Background: The 2024/25 influenza season in Hungary experienced a major surge in cases, the largest since the COVID-19 pandemic. We evaluated influenza vaccine effectiveness (VE) in primary care settings among adults and vaccination target groups, and also according to time since vaccination, prior seasonal vaccination, and influenza type. Methods: A test-negative case–control study was conducted in Hungary. Data and specimens were collected from primary care patients with an acute respiratory infection (ARI). Patients with positive PCR test results for influenza were classified as cases, while those with negative test results for influenza were classified as controls. Adjusted VEs were calculated using logistic regression as (1 − odds ratio of vaccination) × 100. Results: Between November 2024 and May 2025, 2074 patients were included in the analysis, of whom 395 cases had influenza. Of the 129 vaccinated patients, 123 (95%) received trivalent inactivated adjuvanted whole-cell vaccine (TIAV), and 6 (5%) received quadrivalent split-virion vaccine. The VE against any influenza was 53% (95% CI: 13–74) in the 18+ age group and 52% (95% CI: 7–75) in the target group for vaccination. The VE against any influenza was 63% (95% CI: 17–84) 14–89 days after vaccination, and 27% (95% CI: −67–68) 90 days or more after vaccination. The VE against any influenza was 56% (95% CI: 1–80) with both current and prior seasonal vaccination, and 5% (95% CI: −64–45) with only prior seasonal vaccination. The VE against influenza A was 39% (95% CI: −16–68), and against influenza B was 80% (95% CI: 2–96). Conclusions: We observed moderate vaccine effectiveness against any influenza, with higher protection within three months after vaccination. Our research findings provide evidence to inform the development of vaccines and the scheduling of vaccination campaigns, with the aim of maximizing the level of protection provided by vaccines throughout the entire influenza season.