Last week, there was a new controversy over the gap of two doses of Kovid-19 vaccine Coveshield. Three members of the National Technical Advisory Group on Immunization (NTAGI), which had increased the gap to 12-16 weeks, raised the flag in protest. Said that he had no support in this decision. In a hurry, the government sent NTAGI Chief Dr. NK Arora in front of the media and got it cleared.
There has been so much talk on the gap of two doses of Coveshield that when the second dose will be taken, the answer confuses it. In India itself, the gap has changed thrice. Every time it was said that the study has been done in the UK. Based on the data received from him, the gap has been fixed. But now giving second dose to 40+ in UK with a gap of 8 weeks. This decision was taken recently. When the UK said that only double doses provide protection from the delta variant.
Well, we here have the Kovid Task Force that has warned that the Delta + variant in India can bring the third wave of Corona. To deal with this, a vaccination plan like the UK will have to be made. The question will arise that when the gap of two doses has reduced in the UK, then why do we wait for 12 weeks here? Government officials, who take the cover of UK data in everything, have no answer at the moment.
What is this new controversy over the gap of two doses of CoveShield?
- So far, the government has changed the gap of two doses of Coveshield thrice. On May 13, it was extended for the last time to 12-16 weeks. The decision has been questioned by three members of the 14-member NTAGI.
- In an interview to Reuters, members of the group Dr. MD Gupte and Matthew Varghese said that we had only said what the WHO has said. The dose gap was asked to be 8 to 12 weeks. But from 12 to 16 weeks. We didn’t even say that. JP Muliyil, a member of the government’s seven Kovid Working Groups, says that there was a discussion on increasing the gap in NTAGI, but we did not mention 12-16 weeks.
What did the government say when swords were drawn in the group itself?
- The government exposed Dr. NK Arora, the chief of NTAGI. He said that we have taken decisions based on the data of England. Whatever was decided was on scientific basis. CoveShield is an adenovirus vaccine. We are taking decisions on the basis of the change in its behavior. When we discussed in the group, no one opposed the recommendation.
So why widen the gap between two doses of CoveShield till now?
- Dr. Arora says that the vaccination started in India on February 16, then we only had the results of the bridging trials. Based on that, we decided to apply two doses of Coveshield at an interval of 4 to 6 weeks.
- Then came the UK data in April. It was said that if the gap is increased to 12 weeks, then the protection from the vaccine will be 88% instead of 65%. The Alpha variant dominated the UK at the time. We followed them. Increased the gap to 12-16 weeks. But after two-three days a new report came from England. It was found that a single dose of AstraZeneca (Coveshield in India) vaccine gives only 33% protection. At the same time, double dose gives 60% protection.
- Then, around May 15, the discussion started again that in India also the gap should be reduced to 4 or 8 weeks. Then we decided to build a vaccine tracking platform. So that we can know how much protection we are getting from single and double doses. We will continue to take decisions based on whatever developments come to the fore.
So will the gap of two doses decrease again?
- This requires more data. Dr. Gagandeep Kang, a member of the group on vaccination and the country’s top vaccine scientist, told ‘Bhaskar’, ‘Many people are saying that the gap of two doses should be reduced to 8 weeks. But there is no need to be so hasty. The impact of our strategy should be seen.
- He said, ‘When the first UK report came, it was said that one dose gives 33% protection and two doses gives 60% protection. These were all symptomatic infections. That is, mild, moderate and severe were all cases. The data has become more clear in the new report. It was found that single dose saves 71% and double dose by 92% from hospitalization. That’s what we need too. No need to worry about mild infection.
- According to Dr. Kang, the supply is less at this time. It is necessary to give protection to maximum population by giving one dose. If found, high risk groups in 45+ or priority groups may take a second dose in 8 weeks. But for this such a strategy has to be made.
Has there been any study of the effect of dosage in India or is it sitting on the basis of UK?
- Yes, it has happened. A study by PGI Chandigarh has found that equal and 75% protection is provided by single and double doses. We can assume that this protection has been given to us against the Alpha variant, which at that time dominated in Punjab as well as in northern India.
- Then, in April and May, there was a study on healthcare workers at Christian Medical College in Vellore, Tamil Nadu. In this, single dose of Coveshield gave 61% protection and double dose gave 65% protection. That is, the difference is not much. So far studies show that there is only 1% to 5% difference in protection from single and double doses.
- Dr. Kang has another theory. He says – If you look at the sero positivity rate, by January, more than 20% people were infected with corona. Then the first dose would have acted as a booster dose for them. We had more exposure to Kovid here than in the UK. Maybe the effect of one dose is better here than in the UK.