Safety & Immunogenicity of Fractional Doses of Vaccines Among Nigerian Adults- A Randomised Non-Inferiority Triple Blind Trial

Conditions

COVID -19

Musa AZ, Salako AO, Ayorinde JB, Ekama S, Odubela OO, Ige F, Idigbe IE, Ajibaye O, Odubela OR, Egharevba H, Ekpenyong M, Adeneye K, Folahanmi AT, Olojo II, Fowora MA, Okwuraiwe A, Elemuwa U, Ezenyi I, Fraden B, Oba A, Idris GA, Jimoh Y, Akande IR, Ogunwale J, Nwaiwu SO, Omale OL, Oyewunmi OO, Ezeanowi R, Agbabiaka A, Eyinade O, Osho A, Garba A, Yahya B, Musa BM, Ezejiofor O, Ejiro B, Iwalokun BA, Adigwe OP, Adeyeye MC, Faisal S, Ezechi OC, Salako BL.

2025-12-16

10.1186/s13063-025-09317-4

Safety and immunogenicity of fractional COVID-19 vaccine doses in Nigerian adults: A randomized non-inferiority trial

Abideen Salako, Adesola Z. Musa, Fehintola Ige, Adam Abdullahi, Ayorinde Babatunde James et al. (45 authors)

Scientific Reports2025-07-292 citations

10.1038/s41598-025-06536-2

Interventions

Fractional COVID 19 vaccines

Standard COVID 19 vaccines

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Healthy based on medical examination/history at the inclusion Age 18-65 years Signed informed consent Prepared to grant authorized persons access to the medical records The volunteer is likely to comply with instructions Non pregnant female above 18 years

Exclusion criteria

Exclusion criteria: On current treatment with investigational agents for prophylaxis of COVID-19. Plan to travel outside Nigeria from enrolment through 28 days after the last vaccination Participation in other clinical trials Known hypersensitivity to any of the vaccine components History of hypersensitivity or severe allergic reaction Laboratory parameters outside of normal range considered clinically relevant Pregnant woman

Design outcomes

Primary

Measure	Time frame
Geometric Mean Fold Rise (GMFR) of = 2.5 within the range of 20% non-inferiority to the standard dose of anti-SARS-CoV-2 S antibody response 28 days after immunization detected by ELISA termed as seroconversion.;Geometric Mean Fold Rise (GMFR) of = 2.5 within the range of 20% non-inferiority to the standard dose of anti-SARS-CoV-2 S antibody response 28 days after immunization detected by ELISA termed as seroconversion.	—

Measure

Time frame

Geometric Mean Fold Rise (GMFR) of = 2.5 within the range of 20% non-inferiority to the standard dose of anti-SARS-CoV-2 S antibody response 28 days after immunization detected by ELISA termed as seroconversion.;Geometric Mean Fold Rise (GMFR) of = 2.5 within the range of 20% non-inferiority to the standard dose of anti-SARS-CoV-2 S antibody response 28 days after immunization detected by ELISA termed as seroconversion.

—

Secondary

Measure	Time frame
1. Determine 50% Plaque Reduction Neutralization by antibodies against Alpha, Delta, and Kappa variants of SARS-CoV-2. 2. CD4 T cells and CD8 T cells quantitation 3. IFNa, ?-and IL-2 producing CD4 and CD8 T lymphocytes ;1. Determine 50% Plaque Reduction Neutralization by antibodies against Alpha, Delta, and Kappa variants of SARS-CoV-2. 2. CD4 T cells and CD8 T cells quantitation 3. IFNa, ?-and IL-2 producing CD4 and CD8 T lymphocytes	—

Measure

Time frame

1. Determine 50% Plaque Reduction Neutralization by antibodies against Alpha, Delta, and Kappa variants of SARS-CoV-2. 2. CD4 T cells and CD8 T cells quantitation 3. IFNa, ?-and IL-2 producing CD4 and CD8 T lymphocytes ;1. Determine 50% Plaque Reduction Neutralization by antibodies against Alpha, Delta, and Kappa variants of SARS-CoV-2. 2. CD4 T cells and CD8 T cells quantitation 3. IFNa, ?-and IL-2 producing CD4 and CD8 T lymphocytes

—

Countries

Nigeria

Contacts

Public ContactBabatunde Lawal ;Obi Salalo;Adigwe

Director General Nigerian Institute of medical Research Lagos ;Director General Nigerian Institute of Pharmaceutical Research and Development

tundesalako@hotmail.com;o.p.adigwe@gmail.com+2348033832637;+2348051559005

Outcome results

None listed