Protection afforded by previous Vibrio cholerae infection against subsequent disease and infection: A review

Abstract

Background: Cholera is an acute, diarrheal disease caused by Vibrio cholerae O1 or 139 that is associated with a high global burden.

Methods: We analyzed the estimated duration of immunity following cholera infection from available published studies. We searched PubMed and Web of Science for studies of the long-term immunity following cholera infection. We identified 22 eligible studies and categorized them as either observational, challenge, or serological.

Results: We found strong evidence of protection at 3 years after infection in observational and challenge studies. However, serological studies show that elevated humoral markers of potential correlates of protection returned to baseline within 1 year. Additionally, a subclinical cholera infection may confer lower protection than a clinical one, as suggested by 3 studies that found that, albeit with small sample sizes, most participants with a subclinical infection from an initial challenge with cholera had a symptomatic infection when rechallenged with a homologous biotype.

Conclusions: This review underscores the need to elucidate potential differences in the protection provided by clinical and subclinical cholera infections. Further, more studies are warranted to bridge the gap between the correlates of protection and cholera immunity. Understanding the duration of natural immunity to cholera can help guide control strategies and policy.

Fig 1. Study selection flow diagram for search process.

Fig 2. Main findings of the observational studies.

Fig 3. Serum vibriocidal antibody responses in cholera patients in Bangladesh by study and age range.

Responses stratified by age are shown on different lines, and sample sizes may differ throughout various follow-up days. Within a study where the sample size of a follow-up day was unspecified, we set it equal to the smallest sample size of the follow-up days within the study (the most conservative estimate). Statistically significant differences in geometric mean titers of vibriocidal antibodies (P ≤ 0.05, two-tailed) were compared to baseline.

Fig 4. LPS- and OSP-specific IgG memory B cell responses by study and age range.

Samples of LPS-specific IgG MBCs (A) and of OSP-specific IgG MBCs (B) were taken at different time points and compared for a statistically significant difference from baseline levels within a study group (P ≤ 0.05, two-tailed). A study is repeated in multiple lines if different age groups were considered. IgG, immunoglobulin G; LPS, lipopolysaccharide; MBC, memory B cell; OSP, O-specific polysaccharide.