The Centre has written to the states and Union territories, advising them not to share the data of the Electronic Vaccine Intelligence Network (eVIN) system on vaccine stocks and the temperature of vaccine storage at public forums, and stating that it is a "sensitive information and to be used only for programme improvement".

In a recent letter to the states, the Union health ministry said the Centre, with support from the United Nations Development Programme (UNDP), has rolled out the eVIN system under UIP, which is used to track the vaccine stock status and the temperature at all levels of vaccine storage, from national to the sub-district level.