Iron deficiency (ID) anaemia (IDA) is a global public health problem, with the highest prevalence in Africa and in South-East Asia. While immunization programs have achieved high global coverage, vaccines often underperform in low- and middle-income countries (LMIC). The cause remains uncertain, but undernutrition, including ID, likely plays a role. Our recent in vitro and in vivo studies have shown the importance of iron status in adaptive immunity and vaccine response. Hypoferremia blunted T cell, B cell, and neutralizing antibody responses to influenza virus infection in mice, allowing the virus to persist. Iron deficient anaemic Kenyan women receiving intravenous iron at time of vaccination had a better immune response to the first dose of the ChAdOx Coronavirus 19 (COVID-19) vaccine and yellow fever vaccine. Japanese encephalitis and typhoid fever are endemic in Thailand. Vaccines are available but show variable efficacy. Whether ID impairs adult vaccine response to the live attenuated Japanese encephalitis (JE) and the Typhoid Vi polysaccharide (Vi-PS) vaccine and whether iron repletion via iron fortification improves vaccine response is uncertain. The objective of this study is to assess whether IDA in Thai women impairs immune response to the JE and the Typhoid Vi-PS vaccine and whether fortification iron improves their response. In this double-blind randomized controlled trial, IDA women will be assigned to two study groups: group 1 (fortification group) will receive iron-fortified biscuits (15mg iron as ferrous fumarate) for 56 days; group 2 (control group) will receive non-fortified biscuits for 56 days. All women will receive live attenuated JE and Typhoid Vi-PS vaccine on study day 28. Vaccine response will be measured 28 days after vaccination (on day 56) in both groups.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
150
Study cookies fortified with ferrous fumarate, providing 15 mg of elemental iron in each portion.
All participants will be administered the live attenuated JE vaccine
All participants will be administered the typhoid Vi-PS vaccine
Study cookies containing no iron
Mahidol University
Roi Et, Thailand
RECRUITINGImmunoglobulin G (IgG) concentrations against Salmonella Typhi
Time frame: day 28 (time of vaccination)
Immunoglobulin A (IgA) concentrations against Salmonella Typhi
Time frame: day 28 (time of vaccination)
Immunoglobulin G (IgG) concentrations against Salmonella Typhi
Time frame: day 56 (4 weeks after vaccination)
Immunoglobulin A (IgA) concentrations against Salmonella Typhi
Time frame: day 56 (4 weeks after vaccination)
Neutralizing antibodies against Japanese encephalitis
Time frame: day 28 (time of vaccination)
Neutralizing antibodies against Japanese encephalitis
Time frame: day 56 (4 weeks after vaccination)
Hemoglobin concentration (g/dL)
Time frame: day 0
Hemoglobin concentration (g/dL)
Time frame: day 28
Hemoglobin concentration (g/dL)
Time frame: day 56
zinc protoporphyrin (ZnPP) concentration (µmol/mol heme)
Time frame: day 0
zinc protoporphyrin (ZnPP) concentration (µmol/mol heme)
Time frame: day 28
zinc protoporphyrin (ZnPP) concentration (µmol/mol heme)
Time frame: day 56
serum iron (SFe) concentration (ng/µl)
Time frame: day 0
serum iron (SFe) concentration (ng/µl)
Time frame: day 28
serum iron (SFe) concentration (ng/µl)
Time frame: day 56
total iron binding capacity (µg/dL)
Time frame: day 0
total iron binding capacity (µg/dL)
Time frame: day 28
total iron binding capacity (µg/dL)
Time frame: day 56
transferrin saturation (TSAT) (%)
Time frame: day 0
transferrin saturation (TSAT) (%)
Time frame: day 28
transferrin saturation (TSAT) (%)
Time frame: day 56
plasma ferritin (PF) concentration (µg/L)
Time frame: day 0
plasma ferritin (PF) concentration (µg/L)
Time frame: day 28
plasma ferritin (PF) concentration (µg/L)
Time frame: day 56
soluble transferrin receptor (sTfR) concentration (mg/L)
Time frame: day 0
soluble transferrin receptor (sTfR) concentration (mg/L)
Time frame: day 28
soluble transferrin receptor (sTfR) concentration (mg/L)
Time frame: day 56
C-reactive protein (CRP) concentration (mg/L)
Time frame: day 0
C-reactive protein (CRP) concentration (mg/L)
Time frame: day 28
C-reactive protein (CRP) concentration (mg/L)
Time frame: day 56
alpha-glycoprotein (AGP) concentration (g/L)
Time frame: day 0
alpha-glycoprotein (AGP) concentration (g/L)
Time frame: day 28
alpha-glycoprotein (AGP) concentration (g/L)
Time frame: day 56
retinol-binding protein concentration (µmol/L)
Time frame: day 0
retinol-binding protein concentration (µmol/L)
Time frame: day 28
retinol-binding protein concentration (µmol/L)
Time frame: day 56
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