Why did govt extend the interval between Covishield doses to 8 weeks?

The government has increased the time interval between the two doses of Covishield — the Oxford-AstraZeneca vaccine against Covid-19, from four-six weeks to four-eight weeks.

Now, the question remains that why interval between the doses has been raised to 8 weeks? The ministry said in a statement that keeping the existing scientific evidence in mind, it appeared that protection from the vaccine was enhanced if the second dose of Covishield was administered between six and eight weeks but “not later than the stipulated period of eight weeks”.

Why did India increase the interval to eight weeks, and not longer? What do studies say about this vaccine's dosing interval? Who recommended to increased the time interval? What does this mean for India's ongoing vaccination campaign? Listen to the podcast to know