Mid-Term Estimates of Influenza Vaccine Effectiveness against the A(H1N1)pdm09 Prevalent Circulating Subtype in the 2023/24 Season: Data from the Sicilian RespiVirNet Surveillance System
The current influenza season started in Italy in October 2023, approaching the epidemic peak in late December (52nd week of the year). We aimed to explore the mid-term virologic surveillance data of the 2023/2024 influenza season (from 16 October 2023 to 7 January 2024) in Sicily, the fourth most po...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-03-01
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| Series: | Vaccines |
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| Online Access: | https://www.mdpi.com/2076-393X/12/3/305 |
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| author | Claudio Costantino Walter Mazzucco Giorgio Graziano Carmelo Massimo Maida Francesco Vitale Fabio Tramuto |
| author_facet | Claudio Costantino Walter Mazzucco Giorgio Graziano Carmelo Massimo Maida Francesco Vitale Fabio Tramuto |
| author_sort | Claudio Costantino |
| collection | DOAJ |
| description | The current influenza season started in Italy in October 2023, approaching the epidemic peak in late December (52nd week of the year). We aimed to explore the mid-term virologic surveillance data of the 2023/2024 influenza season (from 16 October 2023 to 7 January 2024) in Sicily, the fourth most populous Italian region. A test-negative design was used to estimate the effectiveness of seasonal influenza vaccine (VE) against A(H1N1)pdm09 virus, the predominant subtype in Sicily (96.2% of laboratory-confirmed influenza cases). Overall, 29.2% (<i>n</i> = 359/1230) of oropharyngeal swabs collected from patients with influenza-like illness (ILI) were positive for influenza. Among the laboratory-confirmed influenza cases, 12.5% (<i>n</i> = 45/359) were vaccinated against influenza, with higher prevalence of laboratory-confirmed diagnosis of influenza A among subjects vaccinated with quadrivalent inactivated standard dose (29.4%), live attenuated intranasal (25.1%), and quadrivalent inactivated high-dose (23.8%) influenza vaccines. Comparing influenza vaccination status for the 2023/2024 season among laboratory-confirmed influenza-positive and -negative samples, higher vaccination rates in influenza-negative samples (vs. positive) were observed in all age groups, except for 45–64 years old, regardless of sex and comorbidities. The overall adjusted VE (adj-VE) was 41.4% [95%CI: 10.5–61.6%], whereas the adj-VE was 37.9% [95%CI: −0.7–61.7%] among children 7 months–14 years old and 52.7% [95%CI: −38.0–83.8%] among the elderly (≥65 years old). |
| first_indexed | 2024-04-24T17:46:33Z |
| format | Article |
| id | doaj.art-ca5c513cc63641f59afa6970142d6037 |
| institution | Directory Open Access Journal |
| issn | 2076-393X |
| language | English |
| last_indexed | 2024-04-24T17:46:33Z |
| publishDate | 2024-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Vaccines |
| spelling | doaj.art-ca5c513cc63641f59afa6970142d60372024-03-27T14:07:05ZengMDPI AGVaccines2076-393X2024-03-0112330510.3390/vaccines12030305Mid-Term Estimates of Influenza Vaccine Effectiveness against the A(H1N1)pdm09 Prevalent Circulating Subtype in the 2023/24 Season: Data from the Sicilian RespiVirNet Surveillance SystemClaudio Costantino0Walter Mazzucco1Giorgio Graziano2Carmelo Massimo Maida3Francesco Vitale4Fabio Tramuto5Department of Health Promotion Sciences, Maternal and Infant Care, Internal Medicine and Excellence Specialties “G. D’Alessandro”, University of Palermo, 90127 Palermo, ItalyDepartment of Health Promotion Sciences, Maternal and Infant Care, Internal Medicine and Excellence Specialties “G. D’Alessandro”, University of Palermo, 90127 Palermo, ItalySicilian Reference Laboratory for Integrated Surveillance of Respiratory Viruses, University Hospital of Palermo, 90127 Palermo, ItalyDepartment of Health Promotion Sciences, Maternal and Infant Care, Internal Medicine and Excellence Specialties “G. D’Alessandro”, University of Palermo, 90127 Palermo, ItalyDepartment of Health Promotion Sciences, Maternal and Infant Care, Internal Medicine and Excellence Specialties “G. D’Alessandro”, University of Palermo, 90127 Palermo, ItalyDepartment of Health Promotion Sciences, Maternal and Infant Care, Internal Medicine and Excellence Specialties “G. D’Alessandro”, University of Palermo, 90127 Palermo, ItalyThe current influenza season started in Italy in October 2023, approaching the epidemic peak in late December (52nd week of the year). We aimed to explore the mid-term virologic surveillance data of the 2023/2024 influenza season (from 16 October 2023 to 7 January 2024) in Sicily, the fourth most populous Italian region. A test-negative design was used to estimate the effectiveness of seasonal influenza vaccine (VE) against A(H1N1)pdm09 virus, the predominant subtype in Sicily (96.2% of laboratory-confirmed influenza cases). Overall, 29.2% (<i>n</i> = 359/1230) of oropharyngeal swabs collected from patients with influenza-like illness (ILI) were positive for influenza. Among the laboratory-confirmed influenza cases, 12.5% (<i>n</i> = 45/359) were vaccinated against influenza, with higher prevalence of laboratory-confirmed diagnosis of influenza A among subjects vaccinated with quadrivalent inactivated standard dose (29.4%), live attenuated intranasal (25.1%), and quadrivalent inactivated high-dose (23.8%) influenza vaccines. Comparing influenza vaccination status for the 2023/2024 season among laboratory-confirmed influenza-positive and -negative samples, higher vaccination rates in influenza-negative samples (vs. positive) were observed in all age groups, except for 45–64 years old, regardless of sex and comorbidities. The overall adjusted VE (adj-VE) was 41.4% [95%CI: 10.5–61.6%], whereas the adj-VE was 37.9% [95%CI: −0.7–61.7%] among children 7 months–14 years old and 52.7% [95%CI: −38.0–83.8%] among the elderly (≥65 years old).https://www.mdpi.com/2076-393X/12/3/305influenza epidemicA(H1N1)pdm09vaccine effectivenessvirological surveillancetest-negative design |
| spellingShingle | Claudio Costantino Walter Mazzucco Giorgio Graziano Carmelo Massimo Maida Francesco Vitale Fabio Tramuto Mid-Term Estimates of Influenza Vaccine Effectiveness against the A(H1N1)pdm09 Prevalent Circulating Subtype in the 2023/24 Season: Data from the Sicilian RespiVirNet Surveillance System Vaccines influenza epidemic A(H1N1)pdm09 vaccine effectiveness virological surveillance test-negative design |
| title | Mid-Term Estimates of Influenza Vaccine Effectiveness against the A(H1N1)pdm09 Prevalent Circulating Subtype in the 2023/24 Season: Data from the Sicilian RespiVirNet Surveillance System |
| title_full | Mid-Term Estimates of Influenza Vaccine Effectiveness against the A(H1N1)pdm09 Prevalent Circulating Subtype in the 2023/24 Season: Data from the Sicilian RespiVirNet Surveillance System |
| title_fullStr | Mid-Term Estimates of Influenza Vaccine Effectiveness against the A(H1N1)pdm09 Prevalent Circulating Subtype in the 2023/24 Season: Data from the Sicilian RespiVirNet Surveillance System |
| title_full_unstemmed | Mid-Term Estimates of Influenza Vaccine Effectiveness against the A(H1N1)pdm09 Prevalent Circulating Subtype in the 2023/24 Season: Data from the Sicilian RespiVirNet Surveillance System |
| title_short | Mid-Term Estimates of Influenza Vaccine Effectiveness against the A(H1N1)pdm09 Prevalent Circulating Subtype in the 2023/24 Season: Data from the Sicilian RespiVirNet Surveillance System |
| title_sort | mid term estimates of influenza vaccine effectiveness against the a h1n1 pdm09 prevalent circulating subtype in the 2023 24 season data from the sicilian respivirnet surveillance system |
| topic | influenza epidemic A(H1N1)pdm09 vaccine effectiveness virological surveillance test-negative design |
| url | https://www.mdpi.com/2076-393X/12/3/305 |
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