Dataset Information

No association between inactivated influenza vaccination and influenza viral load at diagnosis among young Japanese children: An observational study of the 2013/2014 through 2017/2018 influenza seasons.

ABSTRACT:

Background

The association between inactivated influenza vaccination and viral load in young children remains unclear.

Methods

During the 2013/2014 to 2017/2018 influenza seasons in Japan, children under 6 years of age with pre-defined influenza-like illness and influenza-positive status by real-time RT-PCR were recruited at pediatric clinics for this observational study. Influenza viral load was measured for the most predominant subtype/lineage in each season. Using median dichotomized viral load as an outcome, a multilevel logistic regression model was applied to estimate the multivariable adjusted odds ratio (MOR) and 95% confidence interval (CI) for higher viral load.

Results

A total of 1,185 influenza-positive children were analyzed. The median log₁₀ viral load copy number (copies per milliliter) was 5.5 (interquartile range, 4.6 to 6.1) and did not differ by vaccination status: 5.5 for unvaccinated, 5.7 for one dose, and 5.5 for two doses (p = 0.67). The MOR of vaccinated (one or two doses) versus unvaccinated children was 1.19 (95% CI: 0.86-1.64). Other factors showing significant associations with higher viral load were positive results for A(H1N1)pdm09 and A(H3N2) in comparison with B/Yamagata. The respective MORs were 3.25 (95% CI: 2.28-4.64) and 1.81 (95% CI: 1.32-2.49). Significantly elevated MORs against higher viral load were also observed for higher body temperature at influenza diagnosis and shorter duration from fever onset to specimen collection.

Conclusion

No association was observed between inactivated-influenza vaccination and viral load at influenza-positive diagnosis. Influenza subtype/lineage, body temperature, and time elapsed since fever onset were significantly associated with viral load.

SUBMITTER: Mukai E

PROVIDER: S-EPMC10603291 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature

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Publications

No association between inactivated influenza vaccination and influenza viral load at diagnosis among young Japanese children: An observational study of the 2013/2014 through 2017/2018 influenza seasons.

Mukai Emiko E Fukushima Wakaba W Morikawa Saeko S Nakata Keiko K Hiroi Satoshi S Fujioka Masashi M Matsushita Tohru T Kubota Megumi M Yagi Yoshina Y Takechi Tetsuhisa T Takasaki Yoshio Y Shindo Shizuo S Yamashita Yuji Y Yokoyama Takato T Kiyomatsu Yumi Y Matsumoto Kazuhiro K Maeda Akiko A Kondo Kyoko K Ito Kazuya K Kase Tetsuo T Ohfuji Satoko S Hirota Yoshio Y

Influenza and other respiratory viruses 20231001 10

<h4>Background</h4>The association between inactivated influenza vaccination and viral load in young children remains unclear.<h4>Methods</h4>During the 2013/2014 to 2017/2018 influenza seasons in Japan, children under 6 years of age with pre-defined influenza-like illness and influenza-positive status by real-time RT-PCR were recruited at pediatric clinics for this observational study. Influenza viral load was measured for the most predominant subtype/lineage in each season. Using median dichot ...[more]

PMID: 37885369

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Project description:BackgroundInfluenza epidemiological and virologic data from Georgia are limited. We aimed to present Influenza Like Illness (ILI) and Severe Acute Respiratory Infection (SARI) surveillance data and characterize influenza viruses circulating in the country over three influenza seasons.MethodsWe analyzed sentinel site ILI and SARI data for the 2014-2017 seasons in Georgia. Patients' samples were screened by real-time RT-PCR and influenza viruses isolated were characterized antigenically by haemagglutination inhibition assay and genetically by sequencing of HA and NA genes.Results32% (397/1248) of ILI and 29% (581/1997) of SARI patients tested were positive for influenza viruses. In 2014-2015 the median week of influenza detection was week 7/2015 with B/Yamagata lineage viruses dominating (79%); in 2015-2016-week 5/2016 was the median with A/H1N1pdm09 viruses prevailing (83%); and in 2016-2017 a bimodal distribution of influenza activity was observed-the first wave was caused by A/H3N2 (55%) with median week 51/2016 and the second by B/Victoria lineage viruses (45%) with median week 9/2017. For ILI, influenza virus detection was highest in children aged 5-14 years while for SARI patients most were aged >15 years and 27 (4.6%) of 581 SARI cases died during the three seasons. Persons aged 30-64 years had the highest risk of fatal outcome, notably those infected with A/H1N1pdm09 (OR 11.41, CI 3.94-33.04, p<0.001). A/H1N1pdm09 viruses analyzed by gene sequencing fell into genetic groups 6B and 6B.1; A/H3N2 viruses belonged to genetic subclades 3C.3b, 3C.3a, 3C.2a and 3C.2a1; B/Yamagata lineage viruses were of clade 3 and B/Victoria lineage viruses fell in clade1A.ConclusionIn Georgia influenza virus activity occurred mainly from December through March in all seasons, with varying peak weeks and predominating viruses. Around one third of ILI/ SARI cases were associated with influenza caused by antigenically and genetically distinct influenza viruses over the course of the three seasons.

Dataset Information

No association between inactivated influenza vaccination and influenza viral load at diagnosis among young Japanese children: An observational study of the 2013/2014 through 2017/2018 influenza seasons.

Background

Methods

Results

Conclusion

Publications

No association between inactivated influenza vaccination and influenza viral load at diagnosis among young Japanese children: An observational study of the 2013/2014 through 2017/2018 influenza seasons.

Similar Datasets

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