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

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.

Conditions

• Iron Deficiency Anemia

Interventions

DIETARY_SUPPLEMENT

Iron supplementation

Iron supplements as 100 mg oral iron as FeSO4 given daily

BIOLOGICAL

MenACWY vaccine

MenACWY vaccination given on day 28 to all participants

BIOLOGICAL

COVID-19 vaccine

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

OTHER

Placebo

matching placebo capsules given daily

BIOLOGICAL

Typhim Vi vaccine

Typhim Vi vaccination given on day 28 to all participants

Sponsors & Collaborators

• Jomo Kenyatta University of Agriculture and Technology

  collaborator OTHER

• University of Oxford

  collaborator OTHER

• Swiss Federal Institute of Technology

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

49 Years

Sex

FEMALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-11-01

Primary Completion

2024-12-31

Completion

2024-12-31

Countries

• Kenya

Study Locations