Dataset Information

Risk Factors and Attack Rates of Seasonal Influenza Infection: Results of the Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS) Seroepidemiologic Cohort Study.

ABSTRACT:

Background

Understanding the attack rate of influenza infection and the proportion who become ill by risk group is key to implementing prevention measures. While population-based studies of antihemagglutinin antibody responses have been described previously, studies examining both antihemagglutinin and antineuraminidase antibodies are lacking.

Methods

In 2015, we conducted a seroepidemiologic cohort study of individuals randomly selected from a population in New Zealand. We tested paired sera for hemagglutination inhibition (HAI) or neuraminidase inhibition (NAI) titers for seroconversion. We followed participants weekly and performed influenza polymerase chain reaction (PCR) for those reporting influenza-like illness (ILI).

Results

Influenza infection (either HAI or NAI seroconversion) was found in 321 (35% [95% confidence interval, 32%-38%]) of 911 unvaccinated participants, of whom 100 (31%) seroconverted to NAI alone. Young children and Pacific peoples experienced the highest influenza infection attack rates, but overall only a quarter of all infected reported influenza PCR-confirmed ILI, and one-quarter of these sought medical attention. Seroconversion to NAI alone was higher among children aged <5 years vs those aged ≥5 years (14% vs 4%; P < .001) and among those with influenza B vs A(H3N2) virus infections (7% vs 0.3%; P < .001).

Conclusions

Measurement of antineuraminidase antibodies in addition to antihemagglutinin antibodies may be important in capturing the true influenza infection rates.

SUBMITTER: Huang QS

PROVIDER: S-EPMC9006182 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Risk Factors and Attack Rates of Seasonal Influenza Infection: Results of the Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS) Seroepidemiologic Cohort Study.

Huang Q Sue QS Bandaranayake Don D Wood Tim T Newbern E Claire EC Seeds Ruth R Ralston Jacqui J Waite Ben B Bissielo Ange A Prasad Namrata N Todd Angela A Jelley Lauren L Gunn Wendy W McNicholas Anne A Metz Thomas T Lawrence Shirley S Collis Emma E Retter Amanda A Wong Sook-San SS Webby Richard R Bocacao Judy J Haubrock Jennifer J Mackereth Graham G Turner Nikki N McArdle Barbara B Cameron John J Reynolds Edwin G EG Baker Michael G MG Grant Cameron C CC McArthur Colin C Roberts Sally S Trenholme Adrian A Wong Conroy C Taylor Susan S Thomas Paul P Duque Jazmin J Gross Diane D Thompson Mark G MG Widdowson Marc-Alain MA

The Journal of infectious diseases 20190101 3

<h4>Background</h4>Understanding the attack rate of influenza infection and the proportion who become ill by risk group is key to implementing prevention measures. While population-based studies of antihemagglutinin antibody responses have been described previously, studies examining both antihemagglutinin and antineuraminidase antibodies are lacking.<h4>Methods</h4>In 2015, we conducted a seroepidemiologic cohort study of individuals randomly selected from a population in New Zealand. We tested ...[more]

PMID: 30016464

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Project description:BackgroundThe effectiveness of currently licensed vaccines against influenza has not been clearly established, especially among individuals at increased risk for complications from influenza. We used a test-negative approach to estimate influenza vaccine effectiveness (IVE) against hospitalization with laboratory-confirmed influenza based on data collected from the Global Influenza Hospital Surveillance Network (GIHSN).Methods and findingsThis was a multi-center, prospective, active surveillance, hospital-based epidemiological study during the 2012-2013 influenza season. Data were collected from hospitals participating in the GIHSN, including five in Spain, five in France, and four in the Russian Federation. Influenza was confirmed by reverse transcription-polymerase chain reaction. IVE against hospitalization for laboratory-confirmed influenza was estimated for adult patients targeted for vaccination and who were swabbed within 7 days of symptom onset. The overall adjusted IVE was 33% (95% confidence interval [CI], 11% to 49%). Point estimates of IVE were 23% (95% CI, -26% to 53%) for influenza A(H1N1)pdm09, 30% (95% CI, -37% to 64%) for influenza A(H3N2), and 43% (95% CI, 17% to 60%) for influenza B/Yamagata. IVE estimates were similar in subjects <65 and ≥65 years of age (35% [95% CI, -15% to 63%] vs.31% [95% CI, 4% to 51%]). Heterogeneity in site-specific IVE estimates was high (I2 = 63.4%) for A(H1N1)pdm09 in patients ≥65 years of age. IVE estimates for influenza B/Yamagata were homogenous (I2 = 0.0%).ConclusionsThese results, which were based on data collected from the GIHSN during the 2012-2013 influenza season, showed that influenza vaccines provided low to moderate protection against hospital admission with laboratory-confirmed influenza in adults targeted for influenza vaccination. In this population, IVE estimates against A(H1N1)pdm09 were sensitive to age group and study site. Influenza vaccination was moderately effective in preventing admissions with influenza B/Yamagata for all sites and age groups.

Project description:BackgroundAnnual estimates of seasonal influenza vaccine effectiveness can guide global risk communication and vaccination strategies to mitigate influenza-associated illness. We aimed to evaluate vaccine effectiveness in countries using the 2023 southern hemisphere influenza vaccine formulation.MethodsWe evaluated end-of-season influenza vaccine effectiveness across eight countries (Argentina, Australia, Brazil, Chile, New Zealand, Paraguay, Thailand, and Uruguay) that used the 2023 southern hemisphere vaccine formulation, with use of a test-negative design. All patients who attended participating hospitals with severe acute respiratory illness were tested by RT-PCR for influenza. We calculated country-specific, network-specific, and pooled vaccine effectiveness against hospitalisation. For countries with sufficient data, we also calculated vaccine effectiveness against intensive care unit (ICU) admission by comparing the odds of vaccination among test-positive cases to that among test-negative controls. We evaluated vaccine effectiveness for groups prioritised for vaccination (young children aged 1-4 years, people aged 5-64 years with underlying health conditions, and older adults aged ≥65 years).FindingsFrom March 5 to Nov 27, 2023, 31 368 individuals were admitted to hospital with severe acute respiratory infection in the eight included countries. Of these, 12 609 individuals admitted to hospital (6452 [51·2%] female and 6157 [48·8%] male) who met inclusion criteria and had complete data were included in the analysis, including 4388 test-positive cases and 8221 test-negative controls. Pooled vaccine effectiveness against hospitalisation with any influenza virus was 51·9% (95% CI 37·2-66·7), with substantial heterogeneity across countries (I2 74%). Vaccine effectiveness against ICU admission from any influenza virus was 67·7% (44·5-81·2) in Chile and 69·7% (45·3-83·3) in Australia. Vaccine effectiveness estimates against hospitalisation were highest for young children (70·9% [47·5-94·4]) and lowest for older adults (47·7% [24·9-70·5]).InterpretationAcross eight countries, 2023 southern hemisphere vaccines were effective in reducing hospitalisations from influenza illness. Use of common protocols can facilitate data pooling to provide a comprehensive evaluation of vaccine effectiveness across settings.FundingUS Centers for Disease Control and Prevention cooperative agreements to the Pan American Health Organization and the Thailand Ministry of Public Health; the Australian Government Department of Health and Aged Care; and the New Zealand Ministry of Health.

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Dataset Information

Risk Factors and Attack Rates of Seasonal Influenza Infection: Results of the Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS) Seroepidemiologic Cohort Study.

Background

Methods

Results

Conclusions

Publications

Risk Factors and Attack Rates of Seasonal Influenza Infection: Results of the Southern Hemisphere Influenza and Vaccine Effectiveness Research and Surveillance (SHIVERS) Seroepidemiologic Cohort Study.

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