Effectiveness of the TYPHIBEV® (Vi-CRM197 conjugate) vaccine introduction in Nepal: a test-negative, case-control study

Objectives
We aimed to evaluate the effectiveness of TYPHIBEV®, which was introduced through a catch-up campaign and routine immunization in Nepal, in preventing blood culture-confirmed typhoid fever among children.

Methods
We conducted a test-negative, case-control study where typhoid test-positive cases were defined as vaccine-eligible pediatric patients who tested positive for Salmonella Typhi by blood culture at participating health facilities and test-negative controls were vaccine-eligible patients who tested negative for S. Typhi on blood cultures. We matched by age, location, date of blood culture, and surveillance site. We used conditional logistic regression to calculate odds ratios(OR), and vaccine effectiveness was calculated as 1-OR.

Results
Between October 1, 2022 and December 31, 2024, 40 typhoid cases and 113 matched, test-negative controls were enrolled. Both cases and controls were similar in sociodemographic characteristics and water, sanitation and hygiene-related ..., , # README: Nepal Typhoid TND Disidentified Dataset

This document describes the structure and variables of the disidentified dataset (`TND_DATA_disidentified.csv`) used in the Nepal Typhoid Vaccine Effectiveness study.

## Dataset Overview

* **File Name**: `TND_DATA_disidentified.csv`
* **Format**: Comma-separated values (CSV)
* **Population**: Children and adolescents aged 15 months to 15 years enrolled in the Test-Negative Design study.
* **Geography**: Nepal

## Missing Data and Skip Logic

Empty cells (null values) in this dataset are intentionally left blank to ensure compatibility with statistical analysis scripts and software. These empty cells primarily represent two scenarios:

1. **Skip Logic (Conditional Branching):** Many variables are only applicable and thus only populated if a previous \"gatekeeper\" variable met a certain condition. For example:
* `vacc_date_unc` and `vacc_type` are only populated if `vacc_yn` (TCV Vaccination status) is 1 (Yes).
* `travel_timing` is..., We have received consent to publish the de-identified data in the public domain, and we are following the Open Access Policy for Gates-funded studes: https://openaccess.gatesfoundation.org/how-to-comply/data-sharing-requirements/. All personal health identifiers and dates were removed.,