tetano
Editor, Senior Moderator
J Infect Dis
. 2024 Nov 14:jiae550.
doi: 10.1093/infdis/jiae550. Online ahead of print. A potential platform for future vaccine trials identifies high incidence of symptomatic and asymptomatic influenza infection among children aged 6-23 months in South Africa
Cheryl Cohen[SUP] 1 2 [/SUP], Mignon du Plessis[SUP] 1 3 [/SUP], Neil Martinson[SUP] 4 5 [/SUP], Jocelyn Moyes[SUP] 1 [/SUP], Sibongile Walaza[SUP] 1 2 [/SUP], Nicole Wolter[SUP] 1 3 [/SUP], Mvuyo Makhasi[SUP] 1 2 [/SUP], Fahima Moosa[SUP] 1 3 [/SUP], Myrna Charles[SUP] 6 [/SUP], Aaron M Samuels[SUP] 6 7 [/SUP], Stefano Tempia[SUP] 7 8 [/SUP], Tumelo Moloantoa[SUP] 4 [/SUP], Bekiwe Ncwana[SUP] 4 [/SUP], Louisa Phalatse[SUP] 4 [/SUP], Amelia Buys[SUP] 4 [/SUP], Alicia Fry[SUP] 9 [/SUP], Eduardo Azziz Baumgartner[SUP] 6 [/SUP], Anne von Gottberg[SUP] 1 3 [/SUP], Jackie Kleynhans[SUP] 1 2 [/SUP]
Affiliations
Background: Approaches for determining whether influenza vaccination prevents infection, attenuates illness, or both, are important for developing improved vaccines. We estimated influenza infection incidence, and evaluated symptom ascertainment methodologies in children to inform future vaccine trial design.
Methods: We conducted a prospective cohort study among children aged 6-23 months from May-October 2022. Study nurses collected symptom and temperature data and mid-turbinate nasal swabs twice-weekly irrespective of symptoms; caregivers entered symptom data daily and collected nasal swabs weekly. Samples were tested for influenza using PCR.
Results: Of 230 healthy, screened children, 93 were enrolled of whom 87 (94%) completed 6-months follow-up. 95% (4245/4476) of scheduled nurse, 90% (2045/2276) of caregiver swabs, 99% (92/93) of baseline blood collections and 67% (9245/13768) of scheduled symptom diaries were completed. PCR-confirmed influenza incidence was 65% (60/93) for ≥1 infection; 11 (18%) individuals had 2 and 1 (2%) had 3 episodes. Of 73 episodes, 55 (75%) had ≥1 symptom and 37 (51%) had fever (measured and/or reported). Median infection duration was 7 days (interquartile range 4-9). Human RNase P gene was detected in 99% (2032/2045) of caregiver-collected swabs, through which 5 additional episodes were identified. Per episode, caregiver's diaries of reported and measured fever were 19%(25/73,34%) and 11%(15/73,21%) higher than nurse-reported (11/73,15%) and -measured fevers (7/73,10%), respectively.
Conclusions: The incidence of influenza infection was high and mainly symptomatic suggesting that this platform could be suitable for future trials of vaccine efficacy and correlates of protection against infection and illness in children.
Keywords: South Africa; burden; influenza; symptoms; transmission; vaccine.
. 2024 Nov 14:jiae550.
doi: 10.1093/infdis/jiae550. Online ahead of print. A potential platform for future vaccine trials identifies high incidence of symptomatic and asymptomatic influenza infection among children aged 6-23 months in South Africa
Cheryl Cohen[SUP] 1 2 [/SUP], Mignon du Plessis[SUP] 1 3 [/SUP], Neil Martinson[SUP] 4 5 [/SUP], Jocelyn Moyes[SUP] 1 [/SUP], Sibongile Walaza[SUP] 1 2 [/SUP], Nicole Wolter[SUP] 1 3 [/SUP], Mvuyo Makhasi[SUP] 1 2 [/SUP], Fahima Moosa[SUP] 1 3 [/SUP], Myrna Charles[SUP] 6 [/SUP], Aaron M Samuels[SUP] 6 7 [/SUP], Stefano Tempia[SUP] 7 8 [/SUP], Tumelo Moloantoa[SUP] 4 [/SUP], Bekiwe Ncwana[SUP] 4 [/SUP], Louisa Phalatse[SUP] 4 [/SUP], Amelia Buys[SUP] 4 [/SUP], Alicia Fry[SUP] 9 [/SUP], Eduardo Azziz Baumgartner[SUP] 6 [/SUP], Anne von Gottberg[SUP] 1 3 [/SUP], Jackie Kleynhans[SUP] 1 2 [/SUP]
Affiliations
- PMID: 39542652
- DOI: 10.1093/infdis/jiae550
Background: Approaches for determining whether influenza vaccination prevents infection, attenuates illness, or both, are important for developing improved vaccines. We estimated influenza infection incidence, and evaluated symptom ascertainment methodologies in children to inform future vaccine trial design.
Methods: We conducted a prospective cohort study among children aged 6-23 months from May-October 2022. Study nurses collected symptom and temperature data and mid-turbinate nasal swabs twice-weekly irrespective of symptoms; caregivers entered symptom data daily and collected nasal swabs weekly. Samples were tested for influenza using PCR.
Results: Of 230 healthy, screened children, 93 were enrolled of whom 87 (94%) completed 6-months follow-up. 95% (4245/4476) of scheduled nurse, 90% (2045/2276) of caregiver swabs, 99% (92/93) of baseline blood collections and 67% (9245/13768) of scheduled symptom diaries were completed. PCR-confirmed influenza incidence was 65% (60/93) for ≥1 infection; 11 (18%) individuals had 2 and 1 (2%) had 3 episodes. Of 73 episodes, 55 (75%) had ≥1 symptom and 37 (51%) had fever (measured and/or reported). Median infection duration was 7 days (interquartile range 4-9). Human RNase P gene was detected in 99% (2032/2045) of caregiver-collected swabs, through which 5 additional episodes were identified. Per episode, caregiver's diaries of reported and measured fever were 19%(25/73,34%) and 11%(15/73,21%) higher than nurse-reported (11/73,15%) and -measured fevers (7/73,10%), respectively.
Conclusions: The incidence of influenza infection was high and mainly symptomatic suggesting that this platform could be suitable for future trials of vaccine efficacy and correlates of protection against infection and illness in children.
Keywords: South Africa; burden; influenza; symptoms; transmission; vaccine.