Efficacy of Oxford jabs at 95% if given 3 months apart: SII2 min read . Updated: 29 Dec 2020, 07:23 AM IST
- SII is manufacturing 50-60 million doses of Covishield a month and will increase its capacity to 100 million doses by March after commissioning its third plant.
AstraZeneca Plc will soon release data showing that the effectiveness of its covid-19 vaccine rises to as much as 95% if the two shots are separated by about 2-3 months, said Adar Poonawalla, chief executive of Serum Institute of India (SII), the British company’s manufacturing partner.
"You’ll be hearing some good news from the UK very soon... It would be a 90-95% effective vaccine if you just keep a two-to-three months’ gap between dose 1 and dose 2. They will make that public with documentation," Poonawalla said at a press conference on Monday. He was speaking at the launch of the company’s pneumococcal conjugate vaccine, the first such indigenous vaccine, under the brand Pneumosil.
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Poonawalla’s comments follow a statement by AstraZeneca CEO Pascal Soirot in an interview with Britain’s Sunday Times newspaper that the company has figured out a “winning formula to get efficacy up there with everybody else". However, Soirot did not provide details to back his claim, and said that the data would be published at “some point".
Efficacy results of AstraZeneca’s vaccine, which it has co-developed with Oxford University, sparked a controversy after it claimed that a dosing error increased the effectiveness of the vaccine. Soirot admitted in the interview: “We would have preferred a simpler set of results."
AstraZeneca’s clinical trials for its vaccine in the UK and Brazil included two separate dosing regimens. A lower dosage gave a greater efficacy of 90% while two full doses a month apart gave a 62% efficacy.
Researchers were unable to explain why the lower dosing regimen—a half dose followed by a full dose one month later—was more effective. Instead, the researchers said they had stumbled upon it by accident and called the superior results “serendipity".
Serum Institute, the contract manufacturer of the vaccine, conducted its own phase 2 and 3 bridging study in India using two full doses, which showed a 62% efficacy in AstraZeneca’s trial. Bridging studies look at safety and immune response to prove that the version being contract manufactured is the same as the original.
Poonawalla on Monday also said the vaccine is expected to get an emergency-use licence from the UK Medicines and Healthcare products Regulatory Agency and the Indian regulator by early January.
The company has manufactured 40-50 million doses so far and would sell these shots primarily in India initially.
“For the first month, we may give most of the volumes to India because if we have to export, we have to go through the WHO pre-qualification procedure, which may take another month or so," Poonawalla said.
The company is manufacturing 50-60 million doses of Covishield a month and will increase its capacity to 100 million doses by March after commissioning its third plant. Poonawalla said he expects a shortage of vaccines in the first six months, but after that, as more vaccine manufacturers’ products are launched, the supply-demand mismatch will ease.
Currently, three manufacturers —SII, Bharat Biotech and Pfizer—have applied for emergency licences, and a subject expert panel set up by the Drug Controller General of India is expected to vet the proposals soon. Earlier this month, SII and Bharat Biotech had approached the panel with their proposals but were told to submit more data, while Pfizer asked for more time to make its presentation.