Oxford vaccine viable even at 60-70% efficacy: Serum Institute
The AstraZeneca-Oxford vaccine candidate, even at the lowest efficacy of 60-70 per cent, is a viable one against the novel coronavirus, the Serum Institute of India (SII) said on Thursday.
SII has partnered with the University of Oxford and AstraZeneca for the manufacture and distribution of the vaccine candidate.
'Even though the lowest efficacy results are at 60-70%, it is a viable vaccine against the virus. That said, varied age groups with different dosage forms will result in slight variations and efficacy. We must be patient and not panic,' SII said in a statement.
India trial results not in
The efficacy results of AstraZeneca were based on trials being conducted in the United Kingdom and Brazil. It does not include the trials of the same vaccine being conducted by the Serum Institute in India. The results of the Indian trials are expected to come out in December.
The statement — a couple of days before PM Narendra Modi is scheduled to visit the company — comes amid an acknowledgment on Wednesday by AstraZeneca of a key error in the dosage received by some of the study participants of its Covid-19 vaccine candidate AZD1222 (named Covishield in India).
According to partial results announced on Monday from ongoing trials in the UK and Brazil, the vaccine showed a striking difference in efficacy, depending on the amount delivered. A regimen of two full doses given a month apart was 62 per cent effective while participants who received half a dose of the vaccine in the first round and then the full dose a month later were found to be 90 per cent less likely to develop Covid-19. The average efficacy was pegged around 70 per cent.
But on Wednesday, according to reports, AstraZeneca admitted that the half dose was an error since some of the vials did not have the right vaccine concentration.
In its statement, SII said there were no concerns about the trial in India.
'The Indian trials are running smoothly with strict adherence to all the necessary processes and protocols. So far, there are no concerns. However, we are going through the data that is available and will make a further statement, if needed,' the statement said.
Phase 3 trials are underway across 17 sites in the country and data on the Indian trials should be out in a month or so, SII CEO Adar Poonawalla had earlier told The Indian Express.
While scientists and experts say a vaccine with efficacy of 60 per cent and above is good, they have, however, raised concerns over the company's communication strategy.
When contacted, Dr Gagandeep Kang, virologist and professor of Christian Medical College, Vellore, said, 'You need to be absolutely straight upfront and transparent. We have learnt that the low dose in the Oxford study with higher efficacy was an accident. To first say that low dose gives 90 per cent efficacy and later say that the dose was an error creates doubt about the process that is unnecessary.'
Saying she 'trusted the researchers at Oxford', Kang said, 'Usually when the researchers at Oxford work on vaccines, they go all the way through Phase 1 and sometimes through Phase 2 of the trial on their own. I understand that in this case, they were advised to not do everything on their own and as early as possible link up with a large vaccine company. Oxford started to work with AstraZeneca and this error in dosing may have happened in that switch from doing early phase studies themselves and the later trials with AstraZeneca. This would need to be informed to the regulators and in the trial registry.'
However, none of this is any reason to dismiss the vaccine, she said. 'This is not a vaccine that should be put in the dustbin just because of 60 per cent efficacy. It is a good vaccine that has exceeded the WHO and FDA benchmarks. There is a lot more data to come and we will learn more when it does,' she said.
Virologist Dr Shahid Jameel said he was intrigued by the results. 'As a scientist, I am now thinking what sort of response would one get if the first dose was even smaller - half of what they give — whether by design or accident, I don't care. Would one get an equal or better response then?' Dr Jameel told.
Calling the results a 'blessing in disguise', he said, 'The advantage is that if half or quarter dose gives a better response, then there would be twice as many vaccine doses to vaccinate people. That is a big plus. Many scientific discoveries have happened serendipitously,' he said.
On Saturday, Prime Minister Narendra Modi is set to visit Serum Institute of India 'to understand the process of vaccine production and distribution'. Officials said the PM would reach around 1 pm and depart around 2.30 pm.
The PM visit will be followed by a visit by ambassadors and High Commissioners from around 100 countries, Pune Divisional Commissioner Saurabh Rao said.