Table 3. Integrating EWARS in a Box into routine surveillance after a health emergency.

Integration optiona	Description	Advantages	Disadvantages
Full cloud computingb	EWARS application and all data are stored on a secure server hosted by a public cloud service provider, but data are still owned by the country where they were collected; the cost of the EWARS application and the server are met by WHO	Automatic software updates are applied centrally and are immediately available throughout the country; the country controls access to data	There is a perception that the country does not own the data, though WHO can provide an additional layer of security and technical support, if desired
Cloud computingb with a local server	EWARS application is stored on a public cloud, but data are stored on a local server; the cost of the EWARS application is met by WHO and that of the local server is met by the country	Software is updated automatically	Data may be lost if the server is not always accessible; data are safer and encryption is stronger with public cloud service providers, such as Amazon Web Services
Local server only	EWARS application and data are stored on a local server; the cost of maintaining EWARS and the server are met by the country	The country has complete control of the server, software and data	Software updates are not applied automatically; software maintenance, including installing upgrades, is more difficult to carry out as WHO has limited access to the server, though regular updates can be provided if requested, but will not be installed every week as usual

EWARS: early warning, alert and response system; WHO: World health Organization.

^a There are no licensing fees or other costs for using the EWARS in a Box application.

^b Cloud computing involves the sharing of computer resources at remote sites, usually over the internet.