Impact of Influenza Vaccination on the Burden of Severe Influenza in the Elderly: Spain, 2017–2020
Annual influenza vaccination is the main strategy to reduce the burden of seasonal influenza epidemics and is recommended for the elderly in most countries with influenza vaccination strategies, with the main objective of preventing hospitalizations and mortality associated with seasonal influenza i...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-06-01
|
| Series: | Vaccines |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-393X/11/6/1110 |
| _version_ | 1827735380133150720 |
|---|---|
| author | Clara Mazagatos Concepción Delgado-Sanz Ana Milagro María Liébana-Rodríguez Amparo Larrauri |
| author_facet | Clara Mazagatos Concepción Delgado-Sanz Ana Milagro María Liébana-Rodríguez Amparo Larrauri |
| author_sort | Clara Mazagatos |
| collection | DOAJ |
| description | Annual influenza vaccination is the main strategy to reduce the burden of seasonal influenza epidemics and is recommended for the elderly in most countries with influenza vaccination strategies, with the main objective of preventing hospitalizations and mortality associated with seasonal influenza in this age group. Studies from different countries have estimated the benefits of seasonal influenza vaccination programs in the elderly, preventing a considerable number of cases, hospitalizations and deaths every year. A study measured the number of medically attended confirmed influenza cases in primary care that are prevented annually by vaccination in the population aged 65 and older in Spain, the Netherlands and Portugal, but estimates of the impact of the national influenza vaccination program in the prevention of severe disease in Spain are lacking. The two objectives of this study were to estimate the burden of severe influenza disease in the Spanish population and to measure the impact of influenza vaccination in the prevention of these outcomes in the population aged 65 years and older. Using influenza surveillance systems put in place before the COVID-19 pandemic, we conducted a retrospective observational study to estimate the burden of hospitalizations and ICU admissions in Spain between 2017–18 and 2019–20, by season and age group. Burden estimates for the 65+ group, combined with vaccine effectiveness (VE) and vaccination coverage (VC) data, were used as input data in an ecological, observational study to estimate the impact of the influenza vaccination program on the elderly. We found a higher burden of severe influenza disease in seasons 2017–18 and 2018–19, with A(H3N2) circulation, and in the youngest and oldest age groups. In those aged 65 and older, we estimated an average of 9900 influenza hospitalizations and 1541 ICU admissions averted by vaccination each year. Seasonal influenza vaccination was able to prevent between 11 and 26% influenza hospitalizations and around 40% ICU admissions in the elderly in the three pre-pandemic seasons. In conclusion, our study complements previous analyses in the primary care setting in Spain and demonstrates the benefits of the annual influenza vaccination program in the prevention of severe influenza disease in the elderly, even in seasons with moderate VE. |
| first_indexed | 2024-03-11T01:51:10Z |
| format | Article |
| id | doaj.art-92a73f5822e541b8a2b8eaa99c49d3c8 |
| institution | Directory Open Access Journal |
| issn | 2076-393X |
| language | English |
| last_indexed | 2024-03-11T01:51:10Z |
| publishDate | 2023-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Vaccines |
| spelling | doaj.art-92a73f5822e541b8a2b8eaa99c49d3c82023-11-18T12:59:21ZengMDPI AGVaccines2076-393X2023-06-01116111010.3390/vaccines11061110Impact of Influenza Vaccination on the Burden of Severe Influenza in the Elderly: Spain, 2017–2020Clara Mazagatos0Concepción Delgado-Sanz1Ana Milagro2María Liébana-Rodríguez3Amparo Larrauri4National Centre of Epidemiology, Institute of Health Carlos III, 28029 Madrid, SpainNational Centre of Epidemiology, Institute of Health Carlos III, 28029 Madrid, SpainMiguel Servet University Hospital, Microbiology, 50009 Zaragoza, SpainServicio Medicina Preventiva, Hospital Universitario Virgen de las Nieves, 18014 Granada, SpainNational Centre of Epidemiology, Institute of Health Carlos III, 28029 Madrid, SpainAnnual influenza vaccination is the main strategy to reduce the burden of seasonal influenza epidemics and is recommended for the elderly in most countries with influenza vaccination strategies, with the main objective of preventing hospitalizations and mortality associated with seasonal influenza in this age group. Studies from different countries have estimated the benefits of seasonal influenza vaccination programs in the elderly, preventing a considerable number of cases, hospitalizations and deaths every year. A study measured the number of medically attended confirmed influenza cases in primary care that are prevented annually by vaccination in the population aged 65 and older in Spain, the Netherlands and Portugal, but estimates of the impact of the national influenza vaccination program in the prevention of severe disease in Spain are lacking. The two objectives of this study were to estimate the burden of severe influenza disease in the Spanish population and to measure the impact of influenza vaccination in the prevention of these outcomes in the population aged 65 years and older. Using influenza surveillance systems put in place before the COVID-19 pandemic, we conducted a retrospective observational study to estimate the burden of hospitalizations and ICU admissions in Spain between 2017–18 and 2019–20, by season and age group. Burden estimates for the 65+ group, combined with vaccine effectiveness (VE) and vaccination coverage (VC) data, were used as input data in an ecological, observational study to estimate the impact of the influenza vaccination program on the elderly. We found a higher burden of severe influenza disease in seasons 2017–18 and 2018–19, with A(H3N2) circulation, and in the youngest and oldest age groups. In those aged 65 and older, we estimated an average of 9900 influenza hospitalizations and 1541 ICU admissions averted by vaccination each year. Seasonal influenza vaccination was able to prevent between 11 and 26% influenza hospitalizations and around 40% ICU admissions in the elderly in the three pre-pandemic seasons. In conclusion, our study complements previous analyses in the primary care setting in Spain and demonstrates the benefits of the annual influenza vaccination program in the prevention of severe influenza disease in the elderly, even in seasons with moderate VE.https://www.mdpi.com/2076-393X/11/6/1110influenzasurveillanceburdenvaccinationevaluation |
| spellingShingle | Clara Mazagatos Concepción Delgado-Sanz Ana Milagro María Liébana-Rodríguez Amparo Larrauri Impact of Influenza Vaccination on the Burden of Severe Influenza in the Elderly: Spain, 2017–2020 Vaccines influenza surveillance burden vaccination evaluation |
| title | Impact of Influenza Vaccination on the Burden of Severe Influenza in the Elderly: Spain, 2017–2020 |
| title_full | Impact of Influenza Vaccination on the Burden of Severe Influenza in the Elderly: Spain, 2017–2020 |
| title_fullStr | Impact of Influenza Vaccination on the Burden of Severe Influenza in the Elderly: Spain, 2017–2020 |
| title_full_unstemmed | Impact of Influenza Vaccination on the Burden of Severe Influenza in the Elderly: Spain, 2017–2020 |
| title_short | Impact of Influenza Vaccination on the Burden of Severe Influenza in the Elderly: Spain, 2017–2020 |
| title_sort | impact of influenza vaccination on the burden of severe influenza in the elderly spain 2017 2020 |
| topic | influenza surveillance burden vaccination evaluation |
| url | https://www.mdpi.com/2076-393X/11/6/1110 |
| work_keys_str_mv | AT claramazagatos impactofinfluenzavaccinationontheburdenofsevereinfluenzaintheelderlyspain20172020 AT concepciondelgadosanz impactofinfluenzavaccinationontheburdenofsevereinfluenzaintheelderlyspain20172020 AT anamilagro impactofinfluenzavaccinationontheburdenofsevereinfluenzaintheelderlyspain20172020 AT marialiebanarodriguez impactofinfluenzavaccinationontheburdenofsevereinfluenzaintheelderlyspain20172020 AT amparolarrauri impactofinfluenzavaccinationontheburdenofsevereinfluenzaintheelderlyspain20172020 |