Therapeutic Equivalence, Immunogenicity, and Safety of Euvichol Oral Cholera Vaccine Formulations Compared with WHO-prequalified Shanchol vaccine in Healthy Children and Adults: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Global shortages of oral cholera vaccines (OCV) and the retirement of the Shanchol vaccine have made alternative formulations essential. A systematic review and meta-analysis was conducted to assess the immunogenicity and safety of various Euvichol formulations in comparison with Shanchol. The study searched PubMed, Embase, MEDLINE, Scopus, and Cochrane CENTRAL databases up to May 2026 for randomized controlled trials (RCTs) comparing any Euvichol variant with Shanchol in healthy individuals aged 1 year and older.

Out of the identified RCTs, five involving 7,253 participants were included in the analysis. The Euvichol formulations were found to have non-inferior and equivalent seroconversion rates to Shanchol for both Vibrio cholerae O1 Inaba and O1 Ogawa serotypes. The immunogenicity was demonstrated by Risk Ratios (RRs) of 1.00 (95% Confidence Interval: 0.98-1.02) and 1.01 (95% Confidence Interval: 0.99-1.04) for Inaba and Ogawa serotypes, respectively, with low heterogeneity (I2=0% and I2=26%).

Log-transformed Geometric Mean Titers provided further confirmation of clinical equivalence for both serotypes.

Additionally, the log-transformed Geometric Mean Titers confirmed clinical equivalence for both serotypes. Overall safety was similar between the Euvichol and Shanchol groups, with no significant differences in the risk of solicited adverse events or specific symptoms like fever. Serious adverse events were extremely rare and not associated with vaccination.

In conclusion, the Euvichol variants were shown to have comparable immunogenicity and safety profiles to the Shanchol vaccine. These findings suggest that the widespread use of modern Euvichol formulations, such as Euvichol-Plus and Euvichol-S, can stabilize global OCV stockpiles and address supply challenges.