J Pediatric Infect Dis Soc . Development of Influenza-Specific CD4 T Cell-Mediated Immunity in Children Following Inactivated Influenza Vaccination

[tetano]

J Pediatric Infect Dis Soc


. 2024 Sep 12iae095.
doi: 10.1093/jpids/piae095. Online ahead of print. Development of Influenza-Specific CD4 T Cell-Mediated Immunity in Children Following Inactivated Influenza Vaccination

Ian Shannon[SUP] 1 [/SUP], Nelson Huertas[SUP] 2 [/SUP], Chantelle L White[SUP] 3 [/SUP], Hongmei Yang[SUP] 4 [/SUP], Jennifer L Nayak[SUP] 2 [/SUP]



Affiliations

• PMID: 39269455
• DOI: 10.1093/jpids/piae095

Abstract

Background: While both cellular and humoral immunity are important in immunologic protection against influenza, how the influenza-specific CD4 T cell response is established in response to early vaccination remains inadequately understood. In this study, we sought to understand how the CD4 T cell response to IIV is established and develops throughout early childhood.
Methods: Influenza-specific CD4 T cell responses were quantified following IIV over two influenza seasons in 47 vaccinated children between 6 months and 8 years of age who had no documented history of natural influenza infection during the study. PBMCs were stimulated with peptide pools encompassing the translated regions of the pH1, H3, HAB, and NP proteins and CD4 T cell responses were assessed via multiparameter flow cytometry.
Results: There was boosting of H3- and HAB-specific CD4 T cells but not cells specific for the pH1 HA protein post-vaccination. A positive correlation between age and the magnitude of the influenza-specific CD4 T cell response was seen, with an overall greater magnitude of IFNγ-producing cells in subjects ≥3 years of age. Changes in CD4 T cell functionality were also noted in older compared to younger children, with increases in CD4 T cells producing IFNγ and TNF or IL-2 as well as IFNγ alone.
Conclusions: IIV elicits a CD4 T cell response to H3 and HAB, with increases in the magnitude of the CD4 T cell response and changes in cellular functionality throughout childhood. This suggests that repeated influenza vaccination contributes to the development of anti-influenza CD4 T cell memory in children.

Keywords: CD4 T cells; Influenza; cellular immunity; immunity; pediatrics.

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[tetano]

F1000Res . Single-centre, randomised clinical trial of the immunomodulatory mechanisms of daily supplementation of palm tocotrienol-rich fraction in healthy human volunteers following influenza vaccination

F1000Res


. 2024 Feb 22:13:135.
doi: 10.12688/f1000research.137005.1. eCollection 2024. Single-centre, randomised clinical trial of the immunomodulatory mechanisms of daily supplementation of palm tocotrienol-rich fraction in healthy human volunteers following influenza vaccination

Ammu Kutty Radhakrishnan[SUP] 1 [/SUP], Badariah Ahmad[SUP] 1 [/SUP], Kanga Rani Selvaduray[SUP] 2 [/SUP], Sitti Rahma Abdul Hafid[SUP] 2 [/SUP], Uma Devi Palanisamy[SUP] 1 [/SUP], Cheng Zsien Zhin[SUP] 3 [/SUP]



Affiliations

• PMID: 39268057
• PMCID: PMC11391185
• DOI: 10.12688/f1000research.137005.1

Abstract

Background: Vitamin E from palm oil, known as the tocotrienol-rich fraction (TRF), has been shown to have immune-enhancing activity. To date, only one dose of TRF (400 mg daily) has been tested in a clinical trial. The proposed study will evaluate the immune-enhancing activity effects of lower doses (200, 100 and 50 mg) in a clinical trial using an influenza vaccine as the immunological challenge.
Methods: A single-centre, randomised, parallel, double-blinded, placebo-controlled clinical trial with balance allocation involving five arms will be conducted. The healthy volunteers recruited will be randomly assigned to one of the arms, and they will be asked to take the respective supplements (400 mg, 200 mg, 100 mg, 50 mg of TRF or placebo) daily with their dinner. The volunteers will receive the influenza vaccine after four weeks. They will be asked to return to the study site four weeks later. A blood sample will be taken for the study at baseline, four and eight weeks. Primary outcome measures will be antibody levels to influenza, blood leucocyte profile and cytokine production. Secondary outcomes will be correlating plasma vitamin E levels with immune responses, plasma proteins and gene expression patterns. The findings from this study will be published in relevant peer-reviewed journals and presented at relevant national and international scientific meetings.
Conclusions: The recent world events have created the awareness of having a healthy and functional immune system. Nutrition plays an important role in helping the immune system to function optimally. This study will show the effects of lower doses of TRF in boosting the immune response of healthy individuals and also elucidate the mechanisms through which TRF exerts its immune-enhancing effects.
Clinical trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR) [ ACTRN12622000844741] dated 15 June 2022.


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