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Effects of Oral Iron Supplementation on Vaccine Response in Iron Deficient Kenyan Women

Effects of Oral Iron Supplementation Before vs. at Time of Vaccination on Immune Response in Iron Deficient Kenyan Women

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05919472
Enrollment
180
Registered
2023-06-26
Start date
2023-07-01
Completion date
2024-07-16
Last updated
2025-12-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Iron Deficiency Anemia

Keywords

Iron deficiency, Anemia, Vaccine response, Women of reproductive age

Brief summary

Iron deficiency (ID) anemia (IDA) is a global public health problem, with the highest prevalence in Africa. Vaccines often underperform in low- and middle- income countries (LMIC), and undernutrition, including ID, likely plays a role. Recent studies have shown the importance of iron status in vaccine response. Intravenous iron given at time of vaccination improved response to yellow fever and COVID-19 vaccines in IDA Kenyan women. Whether oral iron treatment would have a similar beneficial effect on vaccine response is uncertain. Also, timing of oral iron treatment needs further investigation. The co-primary objectives of this study are to assess 1) whether IDA in Kenyan women impairs vaccine response, and whether oral iron treatment improves their response; 2) the timing of oral iron treatment to improve vaccine response (prior to vaccination vs at time of vaccination). We will conduct a double-blind randomized controlled trial in southern Kenya to assess the effects of iron supplementation on response to three single-shot vaccines: Johnson & Johnson COVID- 19 (JJ COVID-19), the quadrivalent meningococcal vaccine (MenACWY) and the typhoid Vi polysaccharide vaccine (Typhim Vi). Women with IDA will be recruited and randomly assigned to three study groups: group 1 (pre- treatment) will receive 100 mg oral iron as ferrous sulfate (FeSO4) daily on days 1-56; group 2 (simultaneous treatment) will receive matching placebo daily on days 1-28, and 200 mg oral iron as FeSO4 daily on days 29-56; and group 3 (control) will receive matching placebo daily on days 1-56. Women in all groups will receive the JJ COVID-19 vaccine, the MenACWY and the Typhim Vi vaccine on day 28. Cellular immune response and serology will be measured at 28 days after vaccination in all groups.

Interventions

DIETARY_SUPPLEMENTOral iron supplementation (pre-treatment)

Iron supplements as 200 mg oral iron as FeSO4 given on alternate day on days 1-56

BIOLOGICALCOVID-19 vaccine

Johnson & Johnson COVID- 19 (JJ COVID-19) vaccination given on day 28 to all participants

BIOLOGICALMenACWY vaccine

MenACWY vaccination given on day 28 to all participants

DIETARY_SUPPLEMENTOral iron supplementation (simultaneous treatment)

Iron supplements as 200 mg oral iron as FeSO4 given on alternate day on days 28-56

Typhim Vi vaccination given on day 28 to all participants

Sponsors

Swiss Federal Institute of Technology
CollaboratorOTHER
University of Oxford
CollaboratorOTHER
Nicole Stoffel
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 49 Years
Healthy volunteers
Yes

Inclusion criteria

* Willing and able to give informed consent for participation in the trial * Female aged 18-49 years * Moderate anemia (Hb \<110 g/L, but not severely anemic with Hb \<80 g/L) • Iron deficient (ZnPP \>40 mmol/mol haem) * Anticipated residence in the study area for the study duration

Exclusion criteria

* Major chronic infectious disease (e.g., HIV infection); * Major chronic non-infectious disease (e.g., Type 2 diabetes, cancer); * Chronic medications; * Use of iron-containing mineral and vitamin supplementation 2 weeks prior to study start; * COVID-19 vaccine or confirmed COVID-19 infection within the past 2 years * MenACWY vaccine in the past * Typhoid vaccine in the past * Pregnant (confirmed by rapid test during screening) or lactating. * Malaria (confirmed by rapid test) à study start will be postponed

Design outcomes

Primary

MeasureTime frame
anti-spike (S1) immunoglobulin (IgG) and anti-receptor-binding domain (RBD) IgG concentrations against severe acute respiratory syndrome (SARS)-Coronavirus (COV)-2 [iU/ml]Day 56
IgG concentration against meningococcal serogroups A, C, W, and Y (anti-MenACWY IgG) [iU/ml]Day 56
IgG concentration against Typhoid [iU/ml]Day 56

Secondary

MeasureTime frame
Hemoglobin concentration (g/L) at study endDays 56
Zinc protoporphyrin concentration (µmol/mol heme) at baselineDay 1
Zinc protoporphyrin concentration (µmol/mol heme) at time of vaccinationDay 28
Zinc protoporphyrin concentration (µmol/mol heme) at study endDay 56
Plasma iron concentration (µg/mL) at baselineDay 1
Plasma iron concentration (µg/mL) at time of vaccinationDay 28
Plasma iron concentration (µg/mL) at study endDay 56
Total iron binding capacity at baselineDay 1
Total iron binding capacity at time of vaccinationDay 28
Total iron binding capacity at study endDay 56
Transferrin saturation (%) at baselineDay 1
Transferrin saturation (%) at time of vaccinationDay 28
Transferrin saturation (%) at study endDay 56
Plasma ferritin concentration (µg/L) at baselineDay 1
Plasma ferritin concentration (µg/L) at time of vaccinationDay 28
Plasma ferritin concentration (µg/L) at study endDay 56
Soluble transferrin receptor concentration (mg/L) at time of vaccinationDay 28
Soluble transferrin receptor concentration (mg/L) at study endDay 56
C-reactive protein concentration (mg/L) at baselineDay 1
C-reactive protein concentration (mg/L) at time of vaccinationDay 28
C-reactive protein concentration (mg/L) at study endDay 56
Retinol binding protein concentration (µmol/L) at baselineDay 1
Retinol binding protein concentration (µmol/L) at time of vaccinationDay 28
Retinol binding protein concentration (µmol/L) at study endDay 56
Alpha-glycoprotein (AGP) concentration at baselineDay 1
Alpha-glycoprotein concentration (g/L) at time of vaccinationDay 28
Alpha-glycoprotein concentration (g/L) at study endDay 56
T-cell response assessed with an enzyme-linked immunosorbent assay (ELISA) detecting IFN-gamma produced by CD4+ and CD8+ T cell responses to SARS-CoV-2 peptides at study endDay 56
COVID-19 specific T cell response measured in peripheral blood mononuclear cells by ELISpot assay quantifying specific cytokines' concentration.Day 56
Typhim Vi specific B-cell response measured in peripheral blood mononuclear cells by ELISpot assay quantifying antibodies' and memory B cell concentration.Day 56
Soluble transferrin receptor concentration (mg/L) at baselineDay 1
Hemoglobin concentration (g/L) at baselineDay 1
Hemoglobin concentration (g/L) at time of vaccinationDay 28

Countries

Kenya

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026