Take second Covishield jab after 12-16 weeks: Govt
- The doubling of the gap between doses from 6-8 weeks to 12-16 applies only to the Covishield dose, with the suggested interval for Covaxin remaining at 4-6 weeks.
Indians who take the first dose of Covishield should wait between 12-16 weeks before taking the second shot, the Union government said on Thursday, approving a new set of recommendations from a technical expert group that will help give the first doses to more people and is consistent with studies that suggest a longer interval may offer better efficacy.
The doubling of the gap between doses from 6-8 weeks to 12-16 applies only to the Covishield dose, with the suggested interval for Covaxin remaining at 4-6 weeks. At least 90% of the doses administered in India are of Covishield, the made-in-India version of the Oxford University-AstraZeneca vaccine, according to the Co-WIN dashboard data as on Thursday.
“Based on the available real life evidence, particularly from the UK, the Covid-19 Working Group agreed for increasing the dosing interval to 12-16 weeks between two doses of Covishield vaccine. No change in interval of Covaxin vaccine doses was recommended,” said a statement by the government.
The statement added that the suggestion was accepted by the National Expert Group on Vaccine Administration for Covid-19 (NEGVAC), headed by Niti Aayog member VK Paul, in its meeting on May 12, and finally by the Union health ministry.
“The earlier recommendation for a gap of 4-6 weeks was based on data available at the time. As more data became available, it was seen that increasing the duration helps,” Paul said at the government’s weekly press briefing on the Covid-10 situation on Thursday.
“Now, this decision is based on periodic reviews and on what we have seen as the real-life experience in UK where millions have taken the dose. The data was closely analysed and WHO experts were consulted, so we can be confident about the science around this decision,” he added.
On March 23, the government expanded the second dose interval to 6-8 weeks from the 4-6 week initially announced for Covishield.
According to officials aware of the matter, who asked not to be named, the government’s expert committees are also deliberating upon questions on if pregnant women or lactating mothers can be given coronavirus vaccines, and whether people who recovered from an infection should wait at least six months before they get a dose.
At present, pregnant or nursing mothers are not included in the list of people eligible for vaccines in India.
Several countries have also deliberated on these questions and some have clear policies. The UK’s Joint Committee on Vaccination and Immunisation (JCVI) has recommended that the second dose of the Oxford-AstraZeneca vaccine be given up to 12 weeks after the first. The European Medicines Agency too recommends a 12 week gap at most, although Spain expanded it to 16 weeks in late April.
Most western expert groups, however, do not suggest a particular embargo for when Covid-recovered people should take a vaccine, as long as they no longer have symptoms of the disease or if they were given some particular treatment during their disease.
“If you were treated for Covid-19 with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a Covid-19 vaccine. Talk to your doctor if you are unsure what treatments you received or if you have more questions about getting a Covid-19 vaccine,” says the US Centers for Disease Control (CDC) in its explainer on Covid-19 vaccination.
Paul denied when asked by reporters if the decision was made to primarily help ease the supply crunch since many states are recording a rush for vaccines, especially since adults below the age of 45 became eligible from May 1.
According to Paul, India has a projected production capacity for the approved vaccines at 73 million for the month, which on average is adequate for just around 2.5 million vaccinations a day -- lower than the peak rate of 4.2 million recorded by the country in early April. Several states have stopped vaccinations and shut down centres due to a lack of doses.
“Please have faith in our scientific processes. The National Technical Advisory Group on Immunisation (NTAGI) is a body of individuals of high integrity. And this body does not only look at Covid-19 vaccinations, it also reviews the entire immunisation process in the country. It has been active from much earlier, and functions purely on the basis of scientific evidence before it,” he added.
Dr Balram Bhargava, director general, Indian Council of Medical Research (ICMR), and secretary, department of health research, also said that among key questions that the experts were dealing with in this pandemic was when to give the second vaccine dose.
“There has been a lot of scientific deliberation on the matter, and much of it is still underway. The Covid-19 working group has already met some four times to discuss this and other issues. The meetings also had developers of Covishield from Oxford and they presented latest data,” he said.
The recommendations for a longer dosing gap comes from a Phase 3 trial data set released in February after studies of the Oxford-AstraZeneca vaccine conducted in Brazil, South Africa and UK found efficacy increased to 82.4% when the second shot was given at 12 weeks or more. Between 6-8 weeks of having been given the second dose, the efficacy was found to be 59.9%.
“It is a good move to extend the gap as there is quality data from UK to suggest that the neutralising ability of the antibodies increased significantly when gap was increased. The second dose works like a booster shot. Giving a time gap, however, is not suitable for a vaccine that is an inactivated whole virion vaccine,” said Dr NK Mehra, immunology and immunogenetics expert, who was formerly a senior faculty and dean at New Delhi’s All India Institute of Medical Sciences.
Dr Gagandeep Kang, one of country’s top vaccinologists, said “Canada’s committee also decided on 4 months as trials showed continued good/improved response after 12 weeks.”