Trial reportBMC medicine2025
A booster dose of an inactivated SARS-CoV-2 vaccine targeting virus variants sustains protective humoral and cellular immunity.
Trial report in BMC medicine, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT05593042 (Phase 2, Randomized, Double-blind Study to Evaluate Immunogenicity Superiority of a Booster Dose With an Omicron or a Trivalent Vaccine Compared to CoronaVac, in Adults Immunized With Different Vaccine Schedules Against SARS-CoV-2 in Chile), which is not on this map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Phase 2, Randomized, Double-blind Study to Evaluate Immunogenicity Superiority of a Booster Dose With an Omicron or a Trivalent Vaccine Compared to CoronaVac, in Adults Immunized With Different Vaccine Schedules Against SARS-CoV-2 in Chile
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
40 authors.
Funding
Abstract
backgroundThe Omicron lineage of SARS-CoV-2 showed a remarkable ability to escape vaccine-induced immunity. In a Phase 2 clinical trial, we investigated whether a third booster/fifth dose of one of three inactivated SARS-CoV-2 vaccine candidates, based on the Delta and Omicron BA.1 variants, enhanced humoral and cellular immune responses against SARS-CoV-2.
methodsVolunteers who received either four doses of CoronaVac® (homologous group, n = 228) or two doses of CoronaVac® followed by two mRNA vaccine doses (heterologous group, n = 298) were randomly assigned to receive an Omicron BA.1-based, trivalent (ancestral, Delta, Omicron BA.1) inactivated vaccine or an additional dose of CoronaVac® (heterologous group only). Local and systemic adverse events were recorded for 7 days after immunization with the fifth dose. Blood samples were collected at the time of immunization (day 0), 28 days post-immunization, and 180 days post-immunization. The immune response induced by vaccination was evaluated by quantifying total IgG against SARS-CoV-2 and neutralizing antibodies, IgG-producing B cells, relative antibody avidity, SARS-CoV-2-specific CD4
resultsThe most common local adverse event was pain at the site of inoculation (deltoid area), reported in 43.2% of the participants. No severe adverse events related to vaccination were recorded. Increased SARS-CoV-2-specific IgGs were observed exclusively in the homologous group at 28 days post-vaccination compared to the pre-immune status. Reduced neutralizing antibodies against the Omicron BA.1 variant were detected in both groups when compared to the ancestral (WT) virus, and no changes in IgG-producing B cells or relative antibody avidity were observed after vaccination. Furthermore, we observed sustained IFN-γ production and the frequency of SARS-CoV-2-specific CD4
conclusionsPrevious immunizations targeting the WT SARS-CoV-2 virus have induced a robust humoral and cellular response in the population, which is sustained by a fifth dose targeting either the Omicron BA.1, Delta, or WT virus.
trial registrationNo. NCT05593042.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.