Covishield vaccine's efficiency goes up if the gap between two doses is more than 28 days, Suresh Jadhav, executive director, SII told NDTV. "Even if the difference is four weeks, it gives good protection, but around 70-80 per cent. If the gap is increased further up to six weeks or eight weeks or 10 weeks, the results are much higher," Jadhav told NDTV.
However, Jadhav added that if the second dose was taken faster, it would certainly guarantee 70 per cent protection to the receiver. "But if you want protection for a longer period and a higher level, it is better to take it after six to eight weeks," he said.
On Saturday, as he launched the immunisation drive, Prime Minister Narendra Modi also emphasised on the need to space out the two doses of the vaccine.
Both the vaccines being used in India—Serum's Covishield and Bharat Biotech's Covaxin—are two dose shots with a prescribed gap of 28 days between the jabs.
He explained that the clinical trial was conducted in phase 3 with a 28-day gap, so that became the standard.
Covishield is a vector vaccine which is slower but cheaper and importantly, can be kept stable for six months at standard refrigerator temperatures.
