Interim 2023/24 influenza A vaccine effectiveness: VEBIS European primary care and hospital multicentre studies, September 2023 to January 2024

Influenza A viruses circulated in Europe from September 2023 to January 2024, with influenza A(H1N1)pdm09 predominance. We provide interim 2023/24 influenza vaccine effectiveness (IVE) estimates from two European studies, covering 10 countries across primary care (EU-PC) and hospital (EU-H) settings. Interim IVE was higher against A(H1N1)pdm09 than A(H3N2): EU-PC influenza A(H1N1)pdm09 IVE was 53% (95% CI: 41 to 63) and 30% (95% CI: -3 to 54) against influenza A(H3N2). For EU-H, these were 44% (95% CI: 30 to 55) and 14% (95% CI: -32 to 43), respectively.

Epidemiologic Features and Control Measures during Monkeypox Outbreak, Spain, June 2022

During June 2022, Spain was one of the countries most affected worldwide by a multicountry monkeypox outbreak with chains of transmission without identified links to disease-endemic countries. We provide epidemiologic features of cases reported in Spain and the coordinated measures taken to respond to this outbreak.

[Changes in Hepatitis A epidemiological pattern in Andalucía: 2007-2017]

OBJECTIVE

Sexual transmission of hepatitis A (HAV) is documented, mainly by risk behaviors in men who have sex with men (MSM). There have been HAV outbreaks in MSM in countries of the European Union in the last years. The aim of this work was to study HAV epidemiology in Andalusia in the last 10 years (2007-2017) and the outbreaks among MSM in this period.

METHODS

Retrospective descriptive study of HAV cases reported in the Andalusia Epidemiological Surveillance System between January 2007 and May 2017. We calculated the annual incidence rate per 100000 habitants. We studied case distribution for gender and age. We used the male-female ratio as an indirect marker for MSM.

RESULTS

The mean annual incidence rate in the study period was 4.09 cases per 100000 habitants, with a difference by sex: 4.7 per 100000 men and 2.53 per 100000 women. Two large outbreaks were detected in this period: one in 2008-2009 and another in 2016-2017. The epidemiological characteristics of these outbreaks differ from the classical pattern of the disease, affecting young MSM with associated sexual risk behaviors.

CONCLUSIONS

MSM play a fundamental role in recent outbreaks of HAV. For disease control we must carry out a different strategy, assessing the introduction of systematic vaccination.

[Outbreaks of Measles in Andalusia, Spain, during the Period 2010-2015]

The Andalusian Surveillance Epidemiological System (SVEA) controls and investigates any notification of measles or any other communicable disease. The aim of this article is to describe the epidemiological characteristics of measles outbreaks occurred in Andalusia in the last five years (2010-2015) and their control measures. In this period three outbreaks were reported: the first one started in Granada in 2010 in a community of objectors to vaccination. Control measures of measles protocol of SVEA were adopted (case isolation, identification and contacts immunization), including judicial measures among the group who refused the vaccination. The second outbreak started in Seville in 2011 in an "area in need of social transformation" and it spread throughout the region. The routine vaccination coverage review was introduced within the surveillance system after those outbreaks, identifying the most vulnerable people. During the first six months of 2015, a small outbreak, of 15 cases, occurred in Granada. The outbreak was controlled mainly due to the early intervention, the health measures adopted in the schools and health centres involved and the high vaccination coverage achieved in the population.

[cycEVA study: case control study measuring influenza vaccine effectiveness in Spain, 2008-2013]

BACKGROUND

In Spain, influenza vaccine effectiveness (EV) is estimated since 2008-09 season through the cycEVA case-control study, the Spanish component of the European I-MOVE (Monitoring Influenza Vaccine Effectiveness in the EU/EEA) network. We aimed at describing cycEVA performance in its five consolidated editions 2008/09 -; 2012/13.

METHODS

During the study period the following indicators were analysed: 1) the participation of sentinel general practitioners and pediatricians (MP), 2) the population studied and the study period, 3) the data quality and 4) the dissemination of the cycEVA results. Trend analysis of the indicators was done using the Cochran-Armitage test to compute the Annual Percentage Change (PCA).

RESULTS

The number of participating MP increased from 164 in 2008-09 to 246 in the following editions. The percentage of MP recruiting at least one patient increased significantly annually (PCA = 15.33%). The percentage of recruited patients included into the analysis increased (PCA=5.91%) from 77% in 2008-09 to more than 95% in the following editions. The percentage of cycEVA patients contributing to the I-MOVE study ranged between 23% and 30% in the pilot and 2011-12 editions respectively.. Final results were disseminated in quartile 2 peer-reviewed journals and 2010-11 and 2011-12 preliminary EV estimates were published in quartile 1 journals. cycEVA publications received 97 citations.

CONCLUSION

cycEVA study achieved more quality information, timely EV estimates and a higher impact of the results.

[Infection by the pandemic virus (H1N1) 2009 in Andalusia]

In April 2009, in response to the WHO's alert due to the existence of human infection cases with a new AH1N1 influenza virus, known as swine flu, Andalusian Health Authorities trigger an specific action plan. The surveillance actions developped provided us with appropriate clinical, epidemiological and virological characteristics of the disease. During the first few days, contingency plans were set up based on epidemiological surveillance and outbreak control measures were adopted through early alert and rapid response systems. After phase 6 was declared, influenza sentinel and severe cases surveillance were used in order to plan healthcare services, to reduce transmission and to identify and protect the most vulnerable population groups. Behaviour of pandemic influenza in Andalusia was similar to that observed in the rest of the world. Atack rate was similar to a seasonal flu and the peak was reached at the 46th/2009 week. Most of them were mild cases and affected particularly to young people. The average age of hospitalised patients was 32. Prior pulmonary disease, smoking and morbid obesity (BMI > 40) were the most common pathologies and risk factors in severe cases. An impact scenario of pandemic wave in Andalusia, with an expected attack rate from 2 to 5%, was prepared considering watt observed in the southern hemisphere. Characteristics of the epidemic concerning its extent, severity and mortality rate were adjusted to this scenario.