Estimation of influenza-attributable burden in primary care from season 2014/2015 to 2018/2019, France

The influenza landscape and vaccination coverage in older adults during the SARS-Cov-2 pandemic: data from Several European Countries and Israel

INTRODUCTION

The Raise Awareness of Influenza Strategies in Europe (RAISE) group gathered information about the healthcare burden of influenza (hospitalizations, intensive care unit [ICU] admissions, and excess deaths), surveillance systems, and the vaccine coverage rate (VCR) in older adults in 18 European countries and Israel.

AREAS COVERED

Published medical literature and official medical documentation on the influenza disease burden in the participating countries were reviewed from 2010/11 until the 2022/23 influenza seasons. Information on the framework for monitoring the disease burden and the provision for ensuring older adults had access to vaccination in their respective countries was provided. Data on influenza VCR in older adults were collected for the 2019/20 to 2022/23 influenza seasons. Data are reported descriptively.

EXPERT OPINION

Influenza presents a significant healthcare burden in older adults. Reporting outcomes across participating countries is heterogeneous, highlighting the need for standardized approaches. Although older adults receive free influenza vaccination, vaccine uptake is highly variable among countries. Moreover, hospitalization rates remain high even in countries reporting a high VCR. Increased awareness and education on the burden of disease and the broader use of improved influenza vaccines for older adults may help reduce the disease burden on this population.

Patient influenza vaccination reduces the risk of hospital-acquired influenza: An incident test negative-case control study in Lyon university hospital, France (2004-2020)

BACKGROUND

Literature is limited on the impact of patient vaccination on the risk of hospital-acquired influenza (HAI). This test negative case-control study nested in a surveillance program aimed at evaluating the effectiveness of influenza vaccination in reducing the risk of HAI in hospitalized patients during 15 influenza seasons (2004-05 to 2019-20).

METHODS

HAI cases were those who developed influenza like illness (ILI) symptoms at least 72 h after hospitalization and had a positive reverse transcriptase-polymerase chain reaction (RT-PCR). Controls were those with ILI symptoms and a negative RT-PCR test. A nasal swab as well as socio-demographic, clinical data and information on influenza vaccination were collected.

RESULTS

Of the 296 patients included, 67 were confirmed HAI cases. Influenza vaccine coverage was significantly higher among controls compared to HAI cases (p = 0.002). The risk of HAI was reduced by almost 60 % in vaccinated patients.

CONCLUSIONS

A better control of HAI can be achieved by vaccinating hospitalized patients.

Epidemiology and genomic characterisation of travel-associated and locally-acquired influenza, Marseille, France

BACKGROUND

The purpose of the study was to challenge the hypothesis of an introduction of influenza viruses by international travellers and subsequent local circulation in Marseille, France.

METHODS

We analysed the epidemiological data of PCR-confirmed cases over an eight-year period and compared the genomic data of local and imported influenza viruses during a six-month period.

RESULTS

Between June 2013 and December 2020, 12,434 patients in the Assistance Publique-Hospitaux de Marseille were diagnosed with an influenza virus infection at the laboratory of the Institut Hospitalo-Universitaire Méditerranéee Infection of Marseille. Half of the patients were below the age of 20. Most of the imported cases were diagnosed outside of epidemic periods. Fourteen genomes of the influenza A virus, including six in international travellers returning from Europe or from the Arabian Peninsula and eight from patients who had not travelled were analysed. Sequences of influenza A/H1N1 virus genomes detected in subjects who had travelled to Saudi Arabia were in the same clade and differed from sequences detected later in a traveller returning from Italy, and in non-travellers who were infected in Marseille. This suggests that influenza viruses imported from Saudi Arabia did not subsequently circulate in Marseille.

CONCLUSION

Future studies with higher numbers of genomes are needed to confirm this result.