India has extended the interval between the two doses to 12-16 weeks, while the UK has cut from 12 weeks to 8 weeks
The interval between the first and second doses of Oxford-AstraZeneca or Covishield vaccine will be eight to 12 weeks and will go on as scheduled, according to Dr Sonam Wangchuk of the National Immunisation Technical Advisory Group (NI-TAG).
However, he said if the vaccines are not available on time, the health ministry will have to come up with another plan.
“The availability of the vaccine on time in the country will decide whether it would be between 8th week to 12th week,” added Dr Sonam Wangchuk.
Meanwhile, for the second dose, the World Health Organization’s recommended period is 8 to 12 weeks after the first dose.
According to a peer-reviewed study published in “The Lancet” in February, the AstraZeneca or Covishield vaccine is more effective when its second dose is given around three months after the first, instead of six weeks later.
Bhutan began the first dose of the vaccination campaign on March 27 and the second dose after 8-week interval was yesterday (May 21) and the 12-week interval would be on June 18.
Recently, India extended the gap between two doses of Covishield COVID-19 vaccine to 12-16 weeks, up from the previous maximum of eight weeks primarily because vaccines were in short supply.
On the other hand, the UK cut the gap from 12 weeks to eight weeks in view of the spread of the B.1.617 variant that originated in India.
“Studies found that the first dose has the protection rate of 76% after 21 days onwards of inoculating the first dose and it would protect from getting severe illness and hospitalization,” Dr Sonam Wangchuk said.
After the second dose, the protection would grow from 76% to 83%, he said.
Moreover, Dr Sonam Wangchuk said people who are not protected by the first dose, second dose would be an advantage for them to get protection.
“In COVID-19 vaccine, the first dose is called the ‘prime dose’ and the second dose is called the ‘booster dose’ that reminds the immune system about the infection,” he said.
Additionally, Dr Sonam Wangchuk said India has extended the interval of the doses to 12-16 weeks as per their findings. However, there are no peer-reviewed study on this and immunization experts are reviewing it.
“If there is a strong evidence reported by other countries, we will have to consider in the light of the shortage of vaccine,” he said, adding that if the vaccine arrives on time they would prefer to go with the interval of eight weeks to 12 weeks.
However, there are also claims that the booster effect can still be obtained after a gap of 12 t0 16 weeks.
During the Press Meet on April 31, Foreign Minister Dr Tandi Dorji said India has assured their support to Bhutan in getting the second dose of the Covishield vaccine.
Additionally, the Lyonpo said the government is also exploring other avenues like receiving 108,000 doses of Covishield or AstraZenenca vaccine and about 5,900 doses of the Pfizer vaccine from the COVAX Facility.
Further, he said the government is also considering the procurement of the Covishield or AstraZeneca vaccine from Korea, Thailand, and Australia, which have now started to produce the vaccine besides India’s Serum Institute. “The government has also ordered some 200,000 doses of the Pfizer vaccine from Pfizer Inc., the American multinational pharmaceutical corporation,” said the Lyonpo.
Thukten Zangpo from Thimphu