Coronavirus disease (COVID-19) technical guidance: The Unity Studies: Early Investigations Protocols
The emergence of a new virus means that understanding transmission patterns, severity, clinical features and risk factors for infection will be limited at the start of an outbreak. To address these unknowns, WHO
has provided Four Early Investigation Protocols (rebranded the WHO Unity Studies).
These protocols are designed to rapidly and systematically collect and share data in a format that facilitates aggregation, tabulation and analysis across different settings globally. One additional study to evaluate environmental contamination of COVID-19
is also provided.
Data collected using these investigation protocols will be critical to refine recommendations for case definitions and surveillance, characterize key epidemiological features of COVID-19, help understand spread, severity, spectrum of disease, and impact on the community and to inform guidance for application of countermeasures such as case isolation and contact tracing.
The Unity Studies: WHO Early Investigations Protocols
| Why Unity Studies? | Study focus | Objectives |
| The First Few COVID-19 X cases and contacts transmission investigation protocol (FFX) | Cases and close contacts in the general population or can be restricted to close settings (like households, health care settings, schools). | The primary objectives of this FFX investigation among cases and close contacts are to provide descriptions or estimates of the:
|
| Household transmission of COVID-19 investigation protocol (HH) | Cases and close contacts in household setting |
|
| Assessment of COVID-19 risk factors among Health workers (HW) protocol | For health workers in a health-care setting in which a confirmed case has received care |
|
| Population-based age-stratified seroepidemiological investigation protocol for COVID-19 | Virus infection in the general population |
|
| Surface sampling of COVID-19 virus: A practical “how to” protocol for health care and public health professionals | For environmental surfaces |
|
For more information, please contact: EarlyInvestigations-2019-nCoV@who.int
A one-pager summarizing on all early investigations is available in several languages
- Access the one-pager summary
More details and web links to the five early investigations protocols and forms are given below:
1 - The First Few X (FFX) Cases and contact investigation protocol for COVID-19 infection
- Access the investigation protocol
The following protocol has been designed to investigate the First Few X number of cases and their close contacts (FFX). It is envisioned that the FFX -COVID-19 investigation will be conducted across several countries or sites with geographical and demographical diversity. Using a standardized protocol such as the protocol provided here, epidemiological exposure data and biological samples can be systematically collected and shared rapidly in a format that can be easily aggregated, tabulated and analyzed across many different settings globally for timely estimates of COVID-19 infection . FFX is the primary investigation protocol to be initiated upon identification of the initial laboratory-confirmed cases of COVID-19 in a country.
For a more targeted approach on specific groups and more precise estimation of epidemiological parameters, two other investigation protocols are available:
2 - Household transmission investigation protocol for COVID-19 infection
Access the investigation protocol 
The household transmission investigation is a case-ascertained prospective study of all identified household contacts of a laboratory confirmed COVID-19 infection. It is intended to provide rapid and early information on the clinical, epidemiological and virological characteristics of COVID-19.
3 - Protocol for assessment of potential risk factors for COVID-19 infection among health care workers in a health care setting
Access the assessment protocol
The extent of -COVID-19 infection in health care settings is not clear, nor whether there are certain risk factors associated with infection in health care workers. The following protocol has been designed to investigate the extent of infection and risk factors for infection among health care workers. Follow-up and testing of respiratory specimens and serum of health care workers within a facility in which a confirmed case of COVID-19 infection is receiving care can provide useful information on transmissibility and routes of transmission and are important for limiting amplification events in health care facilities.
For more information, please contact: EarlyInvestigations-2019-nCoV@who.int.
4 - Population-based age-stratified seroepidemiological investigation protocol for COVID-19 virus infection
This protocol is a population-based, age-stratified prospective study for assessing COVID-19 virus infection. It is intended to provide key epidemiological and serologic characteristics of COVID-19 virus in the general population. This includes the extent of infection in the general population and age-specific infection cumulative incidence, as determined by seropositivity, and the fraction of asymptomatic or subclinical infection
For more information, please contact: EarlyInvestigations-2019-nCoV@who.int
5- Surface sampling of coronavirus disease COVID-19 virus: A practical “how to” protocol for health care and public health professionals
The role of environmental contamination in transmission of COVID-19 virus is currently not clear. This protocol has been designed to determine (viable) virus presence and persistence on fomites in various locations where a patient infected with COVID-19 is currently receiving care or being isolated, and to understand how this may relate to COVID-19 transmission events in these settings. It is therefore important that it is done as part of a comprehensive outbreak investigation and that information obtained by environmental studies is combined with the results of epidemiological, laboratory and sequence data from COVID-19 patient investigations.
For more information, please contact: EarlyInvestigations-2019-nCoV@who.int.