An upcoming study by Oxford University showed that a third dose of the vaccine boosted antibodies to the coronavirus spike protein among participants, it added.
"Taken into account the impact of the pandemic, we will consider extending further" the deadline for the BOJ's measures to ease corporate funding strains caused by the crisis, he said.
Core inflation, which excludes energy prices and other volatile items, rose by 1.3% in the 12 months to April, the Office for National Statistics said.
"This is one of the most powerful cyclones we've faced in India for decades, and after weeks of chaos and devastating loss of life caused by Covid-19, it could not have come at a worse time," said Santanu Chakraborty of the charity Save the Children.