The Chief Investigator of AstraZeneca and the Director of the Oxford Vaccine Group has, in this interview, addressed the present controvery over how long the gap between two doses of Covishield should be, clearly endorsing the Centre’s present policy of a 12-16 week gap.Professor Sir Andrew Pollard has said a vaccination policy that aims to vaccinate the largest number of people in the quickest possible time with at least one dose makes sense in the present circumstances in India.The professor also said that a simple and straightforward comparison between the vaccination policy in Britain and India does not make sense because of the different circumstances in the two countries.In a 35-minute interview to Karan Thapar for The Wire, Pollard, who is also Professor of Paediatric Infection and Immunity at Oxford University, said that in a situation of vaccine shortage it makes sense to ensure a measure of protection for the widest number of people rather than provide a better level of protection for a smaller number of people.He explained this by saying that one dose of the AstraZeneca/Covishield vaccine provides above 70% protection against serious illness and hospitalisation which has to be the main concern. One should not be deterred or deflected by the fact that one dose provides only 30% protection against symptomatic illness.He said symptomatic illness usually means nothing more than a cold, cough and fever, which most people can easily handle. Secondly, he added, as more and more mutations and variants inevitably occur, symptomatic protection from vaccines is likely to diminish and what we need to focus on is a high level of continuing protection against serious illness and hospitalisation.Professor Pollard also told The Wire that Britain reduced the gap between two doses of AstraZeneca at a time when a substantial proportion of the British population was already vaccinated. Therefore, the situation permitted a reduction in the gap. In India the converse is the case. The vast majority of people are unvaccinated and unprotected. Therefore, you need to ensure that as many as possible are protected against serious illness and hospitalisation, even if that means a large number will have lower levels of protection against symptomatic infection.Also watch | ‘Widely Spaced Doses of Covishield Is Not the Right Way to Go’Pollard said another sensible reason for extending the gap in circumstances where the supply of vaccine is short is that the level of protection provided by one dose of AstraZeneca significantly increases in the second and third months after the jab.Questioned about the fact India has extended the gap up to 16 weeks, whereas the old UK policy only extended the gap up till 12 weeks, Pollard said protection from one dose was extremely good till 12 weeks but added it doesn’t fall of a cliff thereafter. He said it’s quite reasonable to assume there is a long extension. He seemed to have no problem with the present Indian policy of extending the gap up to 12-16 weeks.Beneficiaries wait in a queue to recieve COVID-19 vaccine dose at a vaccination centre in Jalandhar, Monday, May 17, 2021. Photo: PTIQuestioned about studies by both Public Health Scotland and Public Health England which show that the efficacy of two doses of AstraZeneca against symptomatic illness caused by the Delta variant is around 20% less than Pfizer, Pollard said these were not as yet definitive findings and, secondly, he repeated his earlier point that one should not focus on protection against symptomatic illness but, instead, on protection against serious illness and hospitalisation. Two doses of AstraZeneca provides a very high level of protection against serious illness and hospitalisation. The recent Public Health England study suggests its 92%. (The same PHE study suggests AstraZeneca provides 71% protection against serious illness and hospitalisation after one dose.)However, Pollard clearly and explicitly said he is not working on a single dose AstraZeneca vaccine. He said, “Two doses are needed”. One may be good but the second is needed to boost protection. He made it clear that he is not working on a one dose strategy.In an earlier interview to The Wire, the Chairman of the Covid Working Group, Dr. N. K. Arora, had said there is a real possibility that a single dose AstraZeneca vaccine could be introduced later this year. Pollard seems to have clearly thrown cold water over that claim.Pollard also told The Wire that as of now AstraZeneca is not thinking of or working on a booster or a third jab. However, he does not believe that if a third jab is necessary AstraZeneca, an adenovirus vectored vaccine, would not be useful. In the interview he explains why.In the interview, Pollard spoke at length about the theoretical possibility of mix and match vaccines but also made it clear that this is still at an extremely early stage. However, his answer does explain why such experiments could prove fruitful.Pollard said he found it difficult to understand why AstraZeneca, despite good Phase 3 results announced in late March, has not got authorisation for use in America.Finally, questioned about Delta+ or AY.1, the recent mutation of the Delta variant, Pollard said it’s too early to say this is a matter of concern and we need more real world data to study Delta+ before we come to any conclusions.In The Wire interview, Pollard was also questioned about European fears that AstraZeneca can cause rare blood clots with a low platelet count and the consequent decision by several European governments to limit the age group who are given the AstraZeneca vaccine. He explained this in terms of the risk benefit analysis done by governments in countries where they believe the risk of adverse consequences after vaccination is of more concern than the benefit conferred by vaccination.Watch the full interview here.
