Safety of a bivalent, killed, whole-cell oral cholera vaccine in pregnant women in Bangladesh: evidence from a randomized placebo-controlled trial

• Published in: BMC infectious diseases Vol. 19; no. 1; pp. 422 - 8
• Main Authors: Khan, Ashraful Islam, Ali, Mohammad, Lynch, Julia, Kabir, Alamgir, Excler, Jean-Louis, Khan, Md Arifuzzaman, Islam, Md Taufiqul, Akter, Afroza, Chowdhury, Fahima, Saha, Amit, Khan, Iqbal Ansary, Desai, Sachin N, Kim, Deok Ryun, Saha, Nirod Chandra, Singh, Ajit P, Clemens, John D, Qadri, Firdausi
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 15.05.2019; BioMed Central; BMC
• Subjects: Abortion, Spontaneous - etiology; Administration, Oral; Adolescent; Adult; Analysis; Bangladesh; Bangladesh - epidemiology; Birth weight; Childbirth & labor; Cholera; Cholera - diagnosis; Cholera - epidemiology; Cholera - prevention & control; Cholera vaccines; Cholera Vaccines - adverse effects; Cholera Vaccines - immunology; Clinical trials; Cohort Studies; Delivery (Childbirth); Exposure; Female; Fetuses; Health aspects; Health risk assessment; Humans; Immunization; Incidence; Infections; Low birth weight; Mass Vaccination; Medical research; Middle Aged; Miscarriage; OCV; Placebo Effect; Pregnancy; Pregnant Women; Premature Birth - etiology; Prenatal Care; Prevention; Public health; Randomization; Risk; Risk factors; Safety; Safety and security measures; Stillbirth; Vaccination; Vaccines; Waterborne diseases; Weight; Womens health; Young Adult; Bangladesh; Haiti; Malawi; India; Bangladesh; Cholera; OCV; Safety; Pregnant women
• ISSN: 1471-2334; 1471-2334
• DOI: 10.1186/s12879-019-4006-3

Cholera increases the risk of harmful effects on foetuses. We prospectively followed pregnant women unaware of their pregnancy status who received a study agent in a clinical trial evaluating the association between exposure to an oral cholera vaccine (OCV) and foetal survival. Study participants were selected from a randomized placebo-controlled trial conducted in Dhaka, Bangladesh. The vaccination campaign was conducted between January 10 and February 4, 2014. We enrolled women who were exposed to an OCV or placebo during pregnancy (Cohort 1) and women who were pregnant after the vaccination was completed (Cohort 2). Our primary endpoint was pregnancy loss (spontaneous miscarriage or stillbirth), and the secondary endpoints were preterm delivery and low birth weight. We employed a log-binomial regression to calculate the relative risk of having adverse outcomes among OCV recipients compared to that among placebo recipients. There were 231 OCV and 234 placebo recipients in Cohort 1 and 277 OCV and 299 placebo recipients in Cohort 2. In Cohort 1, the incidence of pregnancy loss was 113/1000 and 115/1000 among OCV and placebo recipients, respectively. The adjusted relative risk for pregnancy loss was 0.97 (95% CI: 0.58-1.61; p = 0.91) in Cohort 1. We did not observe any variation in the risk of pregnancy loss between the two cohorts. The risks for preterm delivery and low birth weight were not significantly different between the groups in both cohorts. Our study provides additional evidence that exposure to an OCV during pregnancy does not increase the risk of pregnancy loss, preterm delivery, or low birth weight, suggesting that pregnant women in cholera-affected regions should not be excluded in a mass vaccination campaign. The study is registered at ( http://clinicaltrials.gov ). Identifier: NCT02027207 .