Factors associated with COVID-19 autumn 2022 booster uptake in the Netherlands among older adults aged ≥ 60 years and younger adults with chronic conditions.

BACKGROUND: A booster with bivalent COVID-19 vaccine was offered in the Netherlands in autumn, 2022. We aimed to investigate vaccine uptake during the autumn 2022 booster round among the population subgroups at risk for severe COVID-19 that were specifically targeted by this campaign: the medical risk group aged 18-59 years and individuals ≥ 60 years. We calculated booster uptake in both populations and analyzed determinants of booster uptake among those who had received at least one prior COVID-19 vaccination. METHODS: Having had an autumn 2022 booster dose was defined as having received a COVID-19 vaccination between 19 September 2022 and 7 March 2023. The study population included individuals who received at least one previous COVID-19 vaccination. National registries of sociodemographic determinants and COVID-19 vaccination were linked by a unique person identifier. Voting proportions for political parties were included at neighborhood level. Determinants of COVID-19 vaccine autumn booster uptake were ranked by importance by random forest analyses. RESULTS: Booster uptake was 68 % among those aged ≥ 60 and 30 % among those aged 18-59 years with a medical risk factor for severe disease. For both target groups the most important determinant for booster uptake was age (15 % in 18-29 years to 72 % in 80 + years). Voting proportions for progressive liberal political parties ranked second in the random forest analysis in both groups, with an increasing proportion of votes associated with higher uptake. In the 60 + group, household type ranked third, with highest vaccine uptake among married couples without children (72 %) and the lowest uptake among unmarried couples with children (47 %). In the medical risk group, migration status ranked third. Migrants with two parents born abroad had the lowest uptake (18 %), whereas migrants with both parents born in the Netherlands had the highest uptake (35 %). CONCLUSION: The target group of people aged ≥ 60 years was much better reached than the target group of people with a medical risk aged 18-59 years. Uptake varied considerably among subgroups in both target groups. The findings of this study can be used in future vaccination strategies as well as for further research to better understand the drivers and barriers of vaccine uptake among the subgroups with notably low uptake.

Determinants of COVID-19 Vaccine Uptake in The Netherlands: A Nationwide Registry-Based Study.

By September 2022, the uptake of at least one dose of COVID-19 vaccine in the Dutch adult population was 84%. Ecological studies have indicated a lower uptake in certain population groups. We aimed to investigate determinants of COVID-19 vaccine uptake in the Netherlands at individual level to evaluate and optimize implementation of the vaccination program and generate hypotheses for research on drivers of, and barriers to, vaccination. A retrospective database study was performed including the entire Dutch population ≥ 18. Vaccination data (5 January 2021-18 November 2021) were at individual levels linked to sociodemographic data. Random forest analyses ranked sociodemographic determinants of COVID-19 vaccine uptake. The most important determinant was age; uptake increased until the age of 80 (67% in 18-35 years, 92% in 67-79 years, and 88% in those > 80). Personal income and socioeconomic position ranked second and third, followed by migration status. Uptake was lower among individuals in the lowest income group (69%), those receiving social benefits (56%), and individuals with two parents born abroad (59%). Our finding that age is the most important determinant for uptake likely reflects the prioritisation of elderly in the programme and the general understanding of their increased vulnerability. However, our findings also reveal important other disparities in vaccine uptake. How to best address this inequity in future vaccination campaigns requires further research.

Effect of COVID-19 vaccination on mortality by COVID-19 and on mortality by other causes, the Netherlands, January 2021-January 2022.

BACKGROUND: We aimed to estimate vaccine effectiveness (VE) against COVID-19 mortality, and to explore whether an increased risk of non-COVID-19 mortality exists in the weeks following a COVID-19 vaccine dose. METHODS: National registries of causes of death, COVID-19 vaccination, specialized health care and long-term care reimbursements were linked by a unique person identifier using data from 1 January 2021 to 31 January 2022. We used Cox regression with calendar time as underlying time scale to, firstly, estimate VE against COVID-19 mortality after primary and first booster vaccination, per month since vaccination and, secondly, estimate risk of non-COVID-19 mortality in the 5 or 8 weeks following a first, second or first booster dose, adjusting for birth year, sex, medical risk group and country of origin. RESULTS: VE against COVID-19 mortality was > 90 % for all age groups two months after completion of the primary series. VE gradually decreased thereafter, to around 80 % at 7-8 months post-primary series for most groups, and around 60 % for elderly receiving a high level of long-term care and for people aged 90+ years. Following a first booster dose, the VE increased to > 85 % in all groups. The risk of non-COVID-19 mortality was lower or similar in the 5 or 8 weeks following a first dose compared to no vaccination, as well as following a second dose compared to one dose and a booster compared to two doses, for all age and long-term care groups. CONCLUSION: At the population level, COVID-19 vaccination greatly reduced the risk of COVID-19 mortality and no increased risk of death from other causes was observed.

The safety and efficacy of miltefosine in the long-term treatment of post-kala-azar dermal leishmaniasis in South Asia - A review and meta-analysis.

BACKGROUND: Miltefosine (MF) is the only oral drug available for treatment of visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). Although the drug is effective and well tolerated in treatment of VL, the efficacy and safety of MF for longer treatment durations (>28 days) in PKDL remains unclear. This study provides an overview of the current knowledge about safety and efficacy of long treatment courses with MF in PKDL, as a strategy in the VL elimination in South Asia. METHODOLOGY/PRINCIPAL FINDINGS: Literature was searched systematically for articles investigating MF treatment in PKDL. A meta-analysis included eight studies (total 324 PKDL patients) to estimate the efficacy of MF in longer treatment regimens (range 6-16 weeks). We found a per-protocol (PP) initial cure rate of 95.2% (95%CI 89.6-100.8) and a PP definite cure rate of 90% (95%CI 81.6-96.3). Descriptive analysis showed that 20% of patients experienced adverse events, which mostly had an onset in the first week of treatment and were likely to get more severe after four weeks of treatment. Gastrointestinal (GI) side effects such as vomiting, nausea, diarrhoea, and abdominal pain were most common. CONCLUSIONS/SIGNIFICANCE: Longer treatment regimens with MF are effective in PKDL patients in India, however with the caveat that the efficacy has recently been observed to decline. GI side effects are frequent, although mostly mild or moderate. However, on the basis of limited data, we cannot conclude that longer MF treatment regimens are safe. Moreover, VL and PKDL pharmacovigilance studies indicate a risk for serious adverse events, questioning the safety of MF. The provision of safer treatment regimens for PKDL patients are therefore recommended. Until these regimens are identified, it should be considered to halt the use of MF monotherapy for PKDL in order to preserve the drug's efficacy.