Eurosurveillance - Volume 28, Issue 26, 29 June 2023

In early 2020, the I-MOVE-COVID-19 hospital surveillance system was adapted from an existing influenza surveillance system to include hospitalised COVID-19 cases.

To describe trends in the demographic and clinical characteristics of hospitalised COVID-19 cases across Europe during the first 2 years of the pandemic, and to identify associations between sex, age and chronic conditions with admission to intensive care or high dependency units (ICU/HDU) and in-hospital mortality.

We pooled pseudonymised data from all hospitalised COVID-19 cases in 11 surveillance sites in nine European countries, collected between 1 February 2020 and 31 December 2021. Associations between sex, age and chronic conditions, with ICU/HDU admission and in-hospital mortality were examined using Pearson’s chi-squared test, and crude odds ratio (OR) estimates with respective 95% confidence intervals (CI).

Of 25,971 hospitalised COVID-19 cases, 55% were male, 35% were 75 years or older and 90% had a chronic underlying condition. Patients with two or more chronic underlying conditions were significantly more likely to die in-hospital from COVID-19 (OR: 10.84; 95% CI: 8.30–14.16) than those without a chronic condition.

The surveillance demonstrated that males, those 75 years or older and those with chronic conditions were at greater risk of in-hospital death. Over the surveillance period, outcomes tended to improve, likely because of vaccinations. This surveillance has laid the groundwork for further research studies investigating the risk factors of hospitalised COVID-19 cases and vaccine effectiveness.

Arthropod vectors such as ticks, mosquitoes, sandflies and biting midges are of public and veterinary health significance because of the pathogens they can transmit. Understanding their distributions is a key means of assessing risk. VectorNet maps their distribution in the EU and surrounding areas.

We aim to describe the methodology underlying VectorNet maps, encourage standardisation and evaluate output.

s: Vector distribution and surveillance activity data have been collected since 2010 from a combination of literature searches, field-survey data by entomologist volunteers via a network facilitated for each participating country and expert validation. Data were collated by VectorNet members and extensively validated during data entry and mapping processes.

As of 2021, the VectorNet archive consisted of ca 475,000 records relating to > 330 species. Maps for 42 species are routinely produced online at subnational administrative unit resolution. On VectorNet maps, there are relatively few areas where surveillance has been recorded but there are no distribution data. Comparison with other continental databases, namely the Global Biodiversity Information Facility and VectorBase show that VectorNet has 5–10 times as many records overall, although three species are better represented in the other databases. In addition, VectorNet maps show where species are absent. VectorNet’s impact as assessed by citations (ca 60 per year) and web statistics (58,000 views) is substantial and its maps are widely used as reference material by professionals and the public.

VectorNet maps are the pre-eminent source of rigorously validated arthropod vector maps for Europe and its surrounding areas.

The Belgian COVID-19 vaccination campaign aimed to reduce disease spread and severity.

We estimated SARS-CoV-2 variant-specific vaccine effectiveness against symptomatic infection (VEi) and hospitalisation (VEh), given time since vaccination and prior infection.

Nationwide healthcare records from July 2021 to May 2022 on testing and vaccination were combined with a clinical hospital survey. We used a test-negative design and proportional hazard regression to estimate VEi and VEh, controlling for prior infection, time since vaccination, age, sex, residence and calendar week of sampling.

We included 1,932,546 symptomatic individuals, of whom 734,115 tested positive. VEi against Delta waned from an initial estimate of 80% (95% confidence interval (CI): 80–81) to 55% (95% CI: 54–55) 100–150 days after the primary vaccination course. Booster vaccination increased initial VEi to 85% (95% CI: 84–85). Against Omicron, an initial VEi of 33% (95% CI: 30–36) waned to 17% (95% CI: 15–18), while booster vaccination increased VEi to 50% (95% CI: 49–50), which waned to 20% (95% CI: 19–21) 100–150 days after vaccination. Initial VEh for booster vaccination decreased from 96% (95% CI: 95–96) against Delta to 87% (95% CI: 86–89) against Omicron. VEh against Omicron waned to 73% (95% CI: 71–75) 100–150 days after booster vaccination. While recent prior infections conferred higher protection, infections occurring before 2021 remained associated with significant risk reduction against symptomatic infection. Vaccination and prior infection outperformed vaccination or prior infection only.

We report waning and a significant decrease in VEi and VEh from Delta to Omicron-dominant periods. Booster vaccination and prior infection attenuated these effects.