Trial RBR–9nn3scw
Publication Costa Clemens SA, Lancet, 2022
Dates: 2021-08-16 to 2021-09-01
Funding: Mixed (Ministério da Saúde - Brasil (Ministry of Health, Brazil); support from AstraZeneca for serological assays)
Conflict of interest: Yes
| Methods | |
| RCT | |
| Location :
Multicenter / Brazil Follow-up duration (months): 1 | |
| Ad26.COV2-S heterologous booster (n = 306)
BNT162b2 heterologous booster (n = 340) ChAdOx1 heterologous booster (n = 304) CoronaVac homologous booster (n = 290) |
|
| Inclusion criteria | 18 years or older; had received their second doses of CoronaVac 182 days (plus or minus 30 days) before enrolment; female participants were not pregnant, puerperal, or nursing; and all participants had given written informed consent |
| Exclusion criteria | History of laboratory-confirmed COVID-19 (or with fever or acute disease within 3 days before randomisation); serious vaccine-related adverse reactions; known bleeding disorders, neurological disorders, or history of Guillain-Barré syndrome; people with autoimmune disease (excluding people with Hashimoto’s thyroiditis, vitiligo, psoriasis, lupus discords, HIV positive, or on HIV treatment); people on immunosuppressive medications within 15 days of vaccine; receipt of other investigational products, other vaccines within 14 days of enrolment or plans to receive vaccine within 28 days of vaccination, monoclonals within 9 months of day 1 or planned during the study, intravenous immunoglobulin, or other blood products; and any condition that could interfere with the primary objectives or represent additional risk to participants |
| Interventions | |
| Intervention
1 IM booster dose of 5×10¹⁰ vp ChAdOx1, 152-210 days after primary CoronaVac schedule 1 IM booster dose of 30 mcg BNT162b2, 152-210 days after primary CoronaVac schedule 1 IM booster dose of 5×10¹⁰ vp AD26.COV2-S, 152-210 days after primary CoronaVac schedule |
|
| Control
1 IM booster dose of 600 SU CoronaVac, 152-210 days after primary CoronaVac schedule | |
| Participants | |
| Randomized 1240 participants | |
| Characteristics of participants Type of participants: Healthy adults N=1240 476 males Children: 0 Pregnant women: 0 Immunocompromized patients: 3 Mean age: Age range: 21-96 | |
| Description of participants Healthy adults with no history of confirmed covid-19 who had previously received 2 doses of CoronaVac at two centers in Brazil | |
| Primary outcome | |
| In the register Humoral immune response to a homologous or heterologous (3rd dose) booster regimen in individuals previously vaccinated with two doses of Sinovac/Butantan | |
| In the report Non-inferiority of anti-spike IgG antibodies 28 days after the booster dose | |
| Variants description | |
| Variants | |
| Description Circulating variant during study period not reported. In a random subset of 80 participants nAb against delta and omicron were tested and reported (table S5, Fig 5); pre-planned analysis for alpha, beta, gamma, delta | |
| Documents avalaible |
Protocol Yes. In English Statistical plan Yes Data-sharing stated:
Yes |
| Risk of bias Overall The overall risk of bias reported in the table corresponds to the highest risk of bias for the outcomes assessed for the systematic review |
Some concerns |
| General comment | In addition to the published article, the supplementary materials with study protcol, and prospective study registry were used in data extraction and risk of bias assessment. The target sample size specified in the registry (n = 1200) was achieved (n = 1240). Pre-planned immunogenicity analyses for age subgroups and variants of concern were reported. The primary outcome in the report (non-inferiority of anti-spike IgG antibodies) did not fully reflect that in the registry (humoral immune response). |