Is the BIVS scheme for Indian Nationals valid in COVID times? Can someone with a BIVS approved UK visa travel to Dublin?
There are no direct changes to the BIVS, or at least I couldn't find any. The trip may be impossible, however, because of public health precautions, depending on the reason for the trip, the traveler's recent travel history, and, of course, the traveler's state of health.
Keep in mind that to visit Dublin with this visa, the traveler must first visit the United Kingdom, so it will be necessary to comply with two sets of restrictions.
Information for travelers entering the UK: https://www.gov.uk/uk-border-control
Information for travelers visiting Ireland: https://www.gov.ie/en/publication/b4020-travelling-to-ireland-during-the-covid-19-pandemic/
UK page on the British-Irish visa scheme: https://www.gov.uk/government/publications/british-irish-visa-scheme
Irish page on the same: https://www.irishimmigration.ie/coming-to-visit-ireland/british-irish-visa-scheme/