tetano
Editor, Senior Moderator
J Infect Dis
. 2020 Jun 2;jiaa293.
doi: 10.1093/infdis/jiaa293. Online ahead of print.
Influenza A(H1N1)pdm09 but Not A(H3N2) Virus Infection Induces Durable Sero-Protection: Results From the Ha Nam Cohort
Le Nguyen Minh Hoa[SUP] 1 [/SUP], Sheena G Sullivan[SUP] 2 3 4 [/SUP], Le Quynh Mai[SUP] 5 [/SUP], Arseniy Khvorov[SUP] 3 [/SUP], Hoang Vu Mai Phuong[SUP] 5 [/SUP], Nguyen Le Khanh Hang[SUP] 5 [/SUP], Pham Quang Thai[SUP] 5 [/SUP], Le Thi Thanh[SUP] 5 [/SUP], Louise Carolan[SUP] 2 [/SUP], Dang Duc Anh[SUP] 5 [/SUP], Tran Nhu Duong[SUP] 5 [/SUP], Juliet E Bryant[SUP] 1 6 [/SUP], H Rogier van Doorn[SUP] 1 6 [/SUP], Heiman F L Wertheim[SUP] 1 7 [/SUP], Peter Horby[SUP] 1 6 [/SUP], Annette Fox[SUP] 1 2 8 [/SUP]
Affiliations
Abstract
Background: The extent to which influenza recurrence depends upon waning immunity from prior-infection is undefined. We used antibody titres of Ha-Nam cohort participants to estimate protection curves and decay trajectories.
Methods: 270 households participated in influenza-like-illness surveillance and provided blood at intervals spanning RTPCR-confirmed transmission. Sera were tested in haemagglutination inhibition assay. Infection was defined as RTPCR+ influenza-like-illness and/or seroconversion. Median protective titres were estimated using scaled-logistic-regression to model pre-transmission titre against infection status in that season, limiting analysis to households with infection(s). Titres were modelled against month since infection using mixed-effects linear regression to estimate decay and when titres fell below protection-thresholds.
Results: 295 and 314 participants were infected with H1N1pdm09-like and A/Perth/16/09-like (H3N2Pe09) viruses, respectively between December 2008-2012. The proportion of householders not-infected (protected) rose more steeply with titre for H1N1pdm09 than for H3N2Pe09, and estimated 50% protection titres were 19.6 and 37.3, respectively. Post-infection titres started higher against H3N2Pe09 but decayed more steeply than against H1N1pdm09. Sero-protection was estimated to be sustained against H1N1pdm09 but to wane by 8-months for H3N2Pe09.
Conclusions: Estimates indicate that infection induces durable sero-protection against H1N1pdm09 but not H3N2Pe09, which could in part account for the younger age of A(H1N1) versus A(H3N2) cases.
Keywords: Cohort Studies; H1N1 subtype; H3N2 subtype; Influenza A virus; antibody; immunity.
. 2020 Jun 2;jiaa293.
doi: 10.1093/infdis/jiaa293. Online ahead of print.
Influenza A(H1N1)pdm09 but Not A(H3N2) Virus Infection Induces Durable Sero-Protection: Results From the Ha Nam Cohort
Le Nguyen Minh Hoa[SUP] 1 [/SUP], Sheena G Sullivan[SUP] 2 3 4 [/SUP], Le Quynh Mai[SUP] 5 [/SUP], Arseniy Khvorov[SUP] 3 [/SUP], Hoang Vu Mai Phuong[SUP] 5 [/SUP], Nguyen Le Khanh Hang[SUP] 5 [/SUP], Pham Quang Thai[SUP] 5 [/SUP], Le Thi Thanh[SUP] 5 [/SUP], Louise Carolan[SUP] 2 [/SUP], Dang Duc Anh[SUP] 5 [/SUP], Tran Nhu Duong[SUP] 5 [/SUP], Juliet E Bryant[SUP] 1 6 [/SUP], H Rogier van Doorn[SUP] 1 6 [/SUP], Heiman F L Wertheim[SUP] 1 7 [/SUP], Peter Horby[SUP] 1 6 [/SUP], Annette Fox[SUP] 1 2 8 [/SUP]
Affiliations
- PMID: 32484513
- DOI: 10.1093/infdis/jiaa293
Abstract
Background: The extent to which influenza recurrence depends upon waning immunity from prior-infection is undefined. We used antibody titres of Ha-Nam cohort participants to estimate protection curves and decay trajectories.
Methods: 270 households participated in influenza-like-illness surveillance and provided blood at intervals spanning RTPCR-confirmed transmission. Sera were tested in haemagglutination inhibition assay. Infection was defined as RTPCR+ influenza-like-illness and/or seroconversion. Median protective titres were estimated using scaled-logistic-regression to model pre-transmission titre against infection status in that season, limiting analysis to households with infection(s). Titres were modelled against month since infection using mixed-effects linear regression to estimate decay and when titres fell below protection-thresholds.
Results: 295 and 314 participants were infected with H1N1pdm09-like and A/Perth/16/09-like (H3N2Pe09) viruses, respectively between December 2008-2012. The proportion of householders not-infected (protected) rose more steeply with titre for H1N1pdm09 than for H3N2Pe09, and estimated 50% protection titres were 19.6 and 37.3, respectively. Post-infection titres started higher against H3N2Pe09 but decayed more steeply than against H1N1pdm09. Sero-protection was estimated to be sustained against H1N1pdm09 but to wane by 8-months for H3N2Pe09.
Conclusions: Estimates indicate that infection induces durable sero-protection against H1N1pdm09 but not H3N2Pe09, which could in part account for the younger age of A(H1N1) versus A(H3N2) cases.
Keywords: Cohort Studies; H1N1 subtype; H3N2 subtype; Influenza A virus; antibody; immunity.