Relative vaccine effectiveness against COVID-19 hospitalisation in persons aged ≥ 65 years: results from a VEBIS network, Europe, October 2021 to July 2023.

To monitor relative vaccine effectiveness (rVE) against COVID-19-related hospitalisation of the first, second and third COVID-19 booster (vs complete primary vaccination), we performed monthly Cox regression models using retrospective cohorts constructed from electronic health registries in eight European countries, October 2021-July 2023. Within 12 weeks of administration, each booster showed high rVE (≥ 70% for second and third boosters). However, as of July 2023, most of the relative benefit has waned, particularly in persons ≥ 80-years-old, while some protection remained in 65-79-year-olds.

Estimation of COVID-19 vaccine effectiveness against hospitalisation in individuals aged ≥ 65 years using electronic health registries; a pilot study in four EU/EEA countries, October 2021 to March 2022.

By employing a common protocol and data from electronic health registries in Denmark, Navarre (Spain), Norway and Portugal, we estimated vaccine effectiveness (VE) against hospitalisation due to COVID-19 in individuals aged ≥ 65 years old, without previous documented infection, between October 2021 and March 2022. VE was higher in 65-79-year-olds compared with ≥ 80-year-olds and in those who received a booster compared with those who were primary vaccinated. VE remained high (ca 80%) between ≥ 12 and < 24 weeks after the first booster administration, and after Omicron became dominant.

Risk reduction of severe outcomes in vaccinated COVID-19 cases: an analysis of surveillance data from Estonia, Ireland, Luxembourg and Slovakia, January to November 2021.

Despite high COVID-19 vaccine coverage in the EU/EEA, there are increasing reports of SARS-CoV-2 infections and hospitalisations in vaccinated individuals. Using surveillance data from Estonia, Ireland, Luxembourg and Slovakia (January-November 2021), we estimated risk reduction of severe outcomes in vaccinated cases. Increasing age remains the most important driver of severity, and vaccination significantly reduces risk in all ages for hospitalisation (adjusted relative risk (aRR): 0.32; 95% confidence interval (CI): 0.26-0.39) and death (aRR: 0.20; 95% CI: 0.13-0.29).

Enhancing Preparedness for Arbovirus Infections with a One Health Approach: The Development and Implementation of Multisectoral Risk Assessment Exercises.

BACKGROUND: One Health is receiving attention for arbovirus infection prevention and control and for defining national "intersectoral" priorities. Increasing awareness of intersectoral priorities through multisectorial risk assessments (MRA) is promising, where data are not systematically shared between sectors. Towards this aim, the MediLabSecure project organized three MRA exercises (hereby called exercises): one on West Nile virus, one on Crimean-Congo haemorrhagic fever, and one on Rift Valley fever, assessing the added value of this approach. METHODS: The exercises relied on RA methodologies of international organisations. Country representatives of the human and animal virology, medical entomology, and public health sectors (hereby called "sectors") involved in the surveillance of vector-borne diseases participated in the exercises. Background documentation was provided before each exercise, and a guide was developed for the facilitators. All three exercises included technical and methodological presentations and a guided RA directed at bringing into play the different sectors involved. To assess the added value of the approach, each participant was asked to rank the level of perceived benefit of the multisectoral collaboration for each "risk question" included in the exercises. RESULTS: In total, 195 participants from 19 non-EU countries in the Mediterranean and Black Sea regions took part in the exercises. The participants assessed the multisectoral approach as valuable in analysing comprehensively the situation by having access to information and knowledge provided by each of the sectors involved. Sharing of information and discussion facilitated reaching a consensus on the level of risk in each country. CONCLUSIONS: Increasing awareness of intersectoral priorities, including cross-border ones, through MRA is relevant to reduce gaps due to unavailability of shared data and information. Given that six out of the ten threats to global health listed by WHO are occurring at the human-animal-environmental interfaces, comprehensive regional RA with a One Health approach made by national authorities can be a relevant added value for the global health security.

Human papillomavirus vaccination coverage, policies, and practical implementation across Europe.

BACKGROUND: Our objectives were to describe Human Papillomavirus vaccination coverage rates (HPV-VCR), policies, and practical steps for programme implementation that may be linked to high uptake in the population targeted by routine programmes across 30 European Union/European Economic Area Member States and Switzerland. METHODS: Information from institutional websites and from articles indexed in Medline between 01/2006 and 01/2017 was reviewed and extracted using a standardised form. In 12/2017, a cross-sectional survey was administered to national experts, in order to update the compiled information. RESULTS: Data were available in 31 countries, and validated by national experts in 28 of them. National vaccination programmes targeted girls 9-15 years of age in 30 countries and boys in 11 countries. HPV-VCR in girls was monitored in 25 countries: VCR was reported ≥71%(high) in ten countries, 51-70% in seven, 31-50% in four, and ≤30%(very low) in four. In high VCR countries, HPV vaccination was mainly delivered through school health services, and invitation and reminders to attend for vaccination were used. In areas with very low VCR, vaccination tended to be opportunistic and no reminders were used. CONCLUSION: According to our findings, school delivery within structured vaccination programmes and the use of reminders tended to be associated with highest HPV-VCR.

Children Immunization App (CImA) Among Syrian Refugees in Zaatari Camp, Jordan: Protocol for a Cluster Randomized Controlled Pilot Trial Intervention Study.

BACKGROUND: There are up to 19.4 million children who are still unvaccinated and face unnecessary deaths, especially among refugees. However, growing access to smartphones, among refugees, can be a leading factor to improve vaccination rates. OBJECTIVE: This study aims to determine whether a smartphone app can improve the vaccination uptake among refugees and determine the app's effectiveness in improving the documentation of vaccination records. METHODS: We developed and planned to test an app through a cluster randomized trial that will be carried out at the Zaatari refugee camp in Jordan. The study will be open to all parents who carry Android smartphones, have at least one child, and agree to participate in the study. The parents will be recruited to the study by trained volunteers at the vaccination sites around the Zaatari camp. Inclusion criteria will be the following: having at least one child of 0 to 5 years, being a local resident of the camp, and having an Android smartphone. RESULTS: The intervention includes an app that will allow storing Jordanian vaccination records, per child, on the parents' smartphones in Arabic and English (in an interchangeable fashion). Every record will have a set of automated reminders before the appointment of each child. The app will summarize immunization records in form of due, taken, or overdue appointments, labeled in orange, green, and red, respectively. Baseline will include the collection of our primary and secondary outcomes that are needed for the pre and postdata measurements. This includes social demographic data, any previous vaccination history, and electronic health literacy. Participants, in both study arms, will be monitored for their follow-up visits to the clinic for vaccination doses. For the study outcome measures, we will measure any differences in the uptake of vaccinations. The secondary outcome is to analyze the effect of the children immunization app on visits for follow-up doses. CONCLUSIONS: Owing to the limited evidence of effective interventions for childhood vaccination among refugees, research in this area is greatly needed. The project will have a significant impact on the health of refugees and the public health system. In Jordan and the Middle East, the vaccination level is low. Given the influx of refugees from the area, it is crucial to ensure a high vaccination level among the children. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/13557.

Preparedness and response against diseases with epidemic potential in the European Union: a qualitative case study of Middle East Respiratory Syndrome (MERS) and poliomyelitis in five member states.

BACKGROUND: EU Decision 1082/2013/EU on serious cross-border health threats provides a legal basis for collaboration between EU Member States, and between international and European level institutions on preparedness, prevention, and mitigation in the event of a public health emergency. The Decision provides a context for the present study, which aims to identify good practices and lessons learned in preparedness and response to Middle East Respiratory Syndrome (MERS) (in UK, Greece, and Spain) and poliomyelitis (in Poland and Cyprus). METHODS: Based on a documentary review, followed by five week-long country visits involving a total of 61 interviews and group discussions with experts from both the health and non-health sectors, this qualitative case study has investigated six issues related to preparedness and response to MERS and poliomyelitis: national plans and overall preparedness capacity; training and exercises; risk communication; linking policy and implementation; interoperability between the health and non-health sectors; and cross-border collaboration. RESULTS: Preparedness and response plans for MERS and poliomyelitis were in place in the participating countries, with a high level of technical expertise available to implement them. Nevertheless, formal evaluation of the responses to previous public health emergencies have sometimes been limited, so lessons learned may not be reflected in updated plans, thereby risking mistakes being repeated in future. The nature and extent of inter-sectoral collaboration varied according to the sectors involved, with those sectors that have traditionally had good collaboration (e.g. animal health and food safety), as well as those that have a financial incentive for controlling infectious diseases (e.g. agriculture, tourism, and air travel) seen as most likely to have integrated public health preparedness and response plans. Although the formal protocols for inter-sectoral collaboration were not always up to date, good personal relations were reported within the relevant professional networks, which could be brought into play in the event of a public health emergency. Cross-border collaboration was greatly facilitated if the neighbouring country was a fellow EU Member State. CONCLUSIONS: Infectious disease outbreaks remain as an ongoing threat. Efforts are required to ensure that core public health capacities for the full range of preparedness and response activities are sustained.

Field investigation with real-time virus genetic characterisation support of a cluster of Ebola virus disease cases in Dubréka, Guinea, April to June 2015.

On 11 May 2015, the Dubréka prefecture, Guinea, reported nine laboratory-confirmed cases of Ebola virus disease (EVD). None could be epidemiologically linked to cases previously reported in the prefecture. We describe the epidemiological and molecular investigations of this event. We used the Dubréka EVD registers and the Ebola treatment centre's (ETC) records to characterise chains of transmission. Real-time field Ebola virus sequencing was employed to support epidemiological results. An epidemiological cluster of 32 cases was found, of which 27 were laboratory confirmed, 24 were isolated and 20 died. Real-time viral sequencing on 12 cases demonstrated SL3 lineage viruses with sequences differing by one to three nt inside a single phylogenetic cluster. For isolated cases, the average time between symptom onset and ETC referral was 2.8 days (interquartile range (IQR): 1-4). The average time between sample collection and molecular results' availability was 3 days (IQR: 2-5). In an area with scarce resources, the genetic characterisation supported the outbreak investigations in real time, linking cases where epidemiological investigation was limited and reassuring that the responsible strain was already circulating in Guinea. We recommend coupling thorough epidemiological and genomic investigations to control EVD clusters.

Global polio eradication: Where are we in Europe and what next?

The world was never so close to reach the polio eradication: only 37 cases notified in 2016 in only three countries, but the game is not yet at the end. The risk of polio outbreaks in the EU is smaller than it has ever been in the past, but it is not so small that we can ignore it. The EU MS must remain alert and plan and prepare for managing polio events or outbreaks because of the possible dire consequences. The IPV only vaccination schedule universally applied in EU has achieved satisfactory coverage, but constantly leaving small accumulating pockets of susceptible individuals. Moreover the IPV only schedule is not an absolute barrier against poliovirus silent transmission as demonstrated in the recent Israel outbreak. The availability of annually revised S.O.P. from WHO GPEI on the identification and response of a polio event, without local poliovirus transmission or a polio outbreak with sustained transmission, helps and challenge EU countries to update their polio national preparedness plans. The EU/EEA area, in fact, is a peculiar area regarding the polio risk both for its vaccination policy, the large polio vaccines manufactures and the constant immigration from areas at polio high risk, but also EU include cultural and financial potentials crucial to sustain the polio end game strategy and reach the benefit of a world without polio risk. Poliovirus eradication will continue to be challenged as long as there is the worldwide presence of polioviruses in laboratories and vaccine production plants. Most of the world's OPV vaccines are produced in the EU and many laboratories and research centers store and handle polio viruses. EU Member States are engaged actively in implementing the poliovirus biocontainment plans that are part of the polio eradication strategy and to certify the destruction of poliovirus strains and potentially contaminated biological materials.

Immunisation Information Systems - useful tools for monitoring vaccination programmes in EU/EEA countries, 2016.

Immunisation Information Systems (IIS) are computerised confidential population based-systems containing individual-level information on vaccines received in a given area. They benefit individuals directly by ensuring vaccination according to the schedule and they provide information to vaccine providers and public health authorities responsible for the delivery and monitoring of an immunisation programme. In 2016, the European Centre for Disease Prevention and Control (ECDC) conducted a survey on the level of implementation and functionalities of IIS in 30 European Union/European Economic Area (EU/EEA) countries. It explored the governance and financial support for the systems, IIS software, system characteristics in terms of population, identification of immunisation recipients, vaccinations received, and integration with other health record systems, the use of the systems for surveillance and programme management as well as the challenges involved with implementation. The survey was answered by 27 of the 30 EU/EEA countries having either a system in production at national or subnational levels (n = 16), or being piloted (n = 5) or with plans for setting up a system in the future (n = 6). The results demonstrate the added-value of IIS in a number of areas of vaccination programme monitoring such as monitoring vaccine coverage at local geographical levels, linking individual immunisation history with health outcome data for safety investigations, monitoring vaccine effectiveness and failures and as an educational tool for both vaccine providers and vaccine recipients. IIS represent a significant way forward for life-long vaccination programme monitoring.

Post-Ebola Measles Outbreak in Lola, Guinea, January-June 2015(1).

During public health crises such as the recent outbreaks of Ebola virus disease in West Africa, breakdowns in public health systems can lead to epidemics of vaccine-preventable diseases. We report here on an outbreak of measles in the prefecture of Lola, Guinea, which started in January 2015.

Lessons learnt to keep Europe polio-free: a review of outbreaks in the European Union, European Economic Area, and candidate countries, 1973 to 2013.

Between 1973 and 2013, 12 outbreaks of paralytic poliomyelitis with a cumulative total of 660 cases were reported in the European Union, European Economic Area and candidate countries. Outbreaks lasted seven to 90 weeks (median: 24 weeks) and were identified through the diagnosis of cases of acute flaccid paralysis, for which infection with wild poliovirus was subsequently identified. In two countries, environmental surveillance was in place before the outbreaks, but did not detect any wild strain before the occurrence of clinical cases. This surveillance nonetheless provided useful information to monitor the outbreaks and their geographical spread. Outbreaks were predominantly caused by poliovirus type 1 and typically involved unvaccinated or inadequately vaccinated groups within highly immunised communities. Oral polio vaccine was primarily used to respond to the outbreaks with catch-up campaigns implemented either nationwide or in restricted geographical areas or age groups. The introduction of supplementary immunisation contained the outbreaks. In 2002, the European region of the World Health Organization was declared polio-free and it has maintained this status since. However, as long as there are non-vaccinated or under-vaccinated groups in European countries and poliomyelitis is not eradicated, countries remain continuously at risk of reintroduction and establishment of the virus. Continued efforts to reach these groups are needed in order to ensure a uniform and high vaccination coverage.

Does monastic life predispose to the risk of Saint Anthony's fire (herpes zoster)?

BACKGROUND: The consequences of the epidemiology of varicella for zoster epidemiology are still debated. We therefore compared the frequency of herpes zoster in an adult population with virtually no varicella zoster virus (VZV) exposure with that in the general population (GP). METHODS: We performed a national, multicenter, observational, exposed versus nonexposed, comparative study. The nonexposed population consisted of members of contemplative monastic orders (CMO) of the Roman Catholic Church living in 40 isolated monasteries in France. The exposed population consisted of a sample of the GP representative of the French population in terms of age group, sex, socio-occupational categories, and regions. RESULTS: The primary analysis population comprised 920 members of CMO (41.5% nuns; mean age, 64.2 years) and 1533 members of the GP (51.9% women; mean age, 64.6 years). The reported frequency of zoster was 16.2% among CMO and 15.1% in the GP (P = .27, adjusted for sex and age). The reported mean age of onset of zoster was 54.8 and 48.6 years, respectively (P = .06). CONCLUSIONS: This study failed to demonstrate an increased risk or earlier onset of zoster in members of CMO not exposed to VZV, compared with that in the GP. Although adults highly exposed to VZV could have a reduced risk of zoster, compared with the GP, our results suggest that the opposite is not true: adults not exposed to VZV are not at increased risk of zoster when compared with the GP, challenging the relevance of the assumptions and forecasts of current epidemiological models.

Methodology of the sensitivity analysis used for modeling an infectious disease.

Mathematical models may be used to help clarify dynamics of several infectious diseases. Because of the complexity of some models and the high degree of uncertainty in estimating many parameters, the present study proposes a rigorous framework for sensitivity analyses of mathematical models using as example a model to assess varicella and herpes zoster incidence. Its main steps are to assess the uncertainty of the factors to be studied, to evaluate qualitatively and quantitatively the impacts of these factors on model results, and to conduct an univariate and multivariate sensitivity analysis. The application of this technique may have considerable utility in the analysis of a wide variety of complex biological and epidemiological models.

Occurrence of adverse events following inadvertent administration of childhood vaccines.

As a service to healthcare professionals, Aventis Pasteur MSD UK Ltd. operates a telephone-based Vaccine Information Service, providing information on all aspects of vaccination. In the UK it is the primary means by which spontaneous adverse drug reaction reports are received by the company. It was brought to the attention of the Pharmacovigilance Department that a significant number of calls related to people seeking advice following inadvertent administration of vaccines. To inform our advice it was decided to collect details of such episodes, to enquire whether an adverse drug reaction had already occurred, and to encourage reporting of adverse drug reaction that may occur subsequently. Inadvertent vaccination during pregnancy was not included in this survey since these data were already being collected separately. During the period from 1 September 1999 to 31 August 2000 the Vaccine Information Service received 124010 enquiries. Of these, 302 (0.2%) concerned inadvertent administration of one or more vaccines (all age groups), 161 (53.2% of total inadvertent administration) of them in children (<18 years). These 161 reports involved the inadvertent administration of 221 vaccines. In six cases (3.8%) one or more adverse drug reaction were reported following the inadvertent administration. Five of these six cases involved a DTP-containing vaccine: one case where DTP was given instead of diphtheria and tetanus toxoid (DT) vaccine as a pre-school booster, one case where a fourth dose of DTP-Haemophilus influenzae type b conjugate vaccine (Hib) was given at 20 weeks of age and three cases where DTP was mixed with DTP-Hib. The sixth case involved a child given an adult dose of hepatitis B vaccine. Data are available for five of these six cases-all adverse drug reactions were non-serious and resolved without sequelae.Inadvertent administration of vaccines in childhood, although worrying for both the healthcare professionals and the parents involved, seems rarely to result in adverse reactions.