United States’ top infectious disease expert Dr Anthony Fauci on Thursday backed India’s decision to extend the gap between two doses of the Covishield vaccine, ANI reported. In an interview to the news agency, Fauci said it was a “reasonable approach” to take when faced with a shortage of vaccines.

“When you don’t have enough vaccines, you have got to get as many people vaccinated as you possibly can,” Fauci said. “...Extending the duration between the first and second dose in order to get people at least a first dose is a reasonable approach. It is very unlikely that it would have a negative effect on the efficacy of the vaccine.”

Earlier on Thursday, the Centre said that the gap between two doses of the Covishield vaccine can be increased to 12-16 weeks, from the previous recommended interval of six to eight weeks. The government, has , however, not linked the move to a shortage of vaccines. The decision came after it was recommended by the National Technical Advisory Group on Immunisation. The panel also made a case for deferring vaccination by six months after recovery for those who have been infected by coronavirus.

A study published in medical journal Lancet in March showed that the efficacy of the Covishield vaccine, initially developed by pharmaceutical company AstraZeneca rose to 81.3% when the two doses were given at a gap of 12 weeks, from 55.1% when administered less than six weeks apart. However, there is no study available yet on the effect on efficacy when the gap is more than 12 weeks.

Taking note of the fact that only “a couple of percentage” of India’s population has so far been fully vaccinated, Fauci said it was imperative for India to collaborate with other countries and companies to ramp up its vaccine production. “India is one of the best if not biggest vaccine producers... You have got to use some resources for your people,” he said.

So far, close 3.93 crore beneficiaries in India have received both doses of the vaccine, which accounts for 2.80% of the total population of nearly 140 crore. A total of nearly 17.84 crore doses have been administered, according to government data.

While responding to a query on resuming travel between India and the United States, Fauci said it depended on the level of infection. “Right now India has a very high level of infection and it would be very, very difficult to resume travel,” he said.

He added that it will be up to individual airlines in the US, and not the federal government, whether they make it mandatory for passengers to produce a vaccination certificate before allowing them to fly. US has put a restriction on travel from India since May 4.