AstraZeneca's COVID vaccine efficacy unclear; emergency approval likely by Jan: Nomura

AstraZeneca's recent results regarding Phase III clinical trials of its COVID-19 vaccine is a "bit unclear on the efficacy" as there is too much divergence between two cohorts, says Japanese research firm Nomura. The agency said that more data would be required to establish higher efficacy.

The coronavirus vaccine, developed by Oxford University and British-Swedish pharma major AstraZeneca, achieved a 90 per cent efficacy rate in subjects who received a half-dose followed by a full-dose booster after a month. However, the vaccine was just 62 per cent effective in cases where a full dose was given initially and the next full shot with a gap of one month. These interim results were based on a total of 131 COVID-19 cases studied during the Phase III clinical trials from the UK and Brazil.  

Nomura, in its report, said that AstraZeneca's efficacy data is unclear, as it is very divergent between the two cohorts. "Whether half a dose of vaccine initially instead of a full dose led to the higher efficacy is unclear. The cohort with 90 per cent efficacy was smaller, thus we think the total number of individuals infected in this cohort would be small at around 20-30 (out of 131)," the report noted.  

AstraZeneca, based on the interim Phase III results, will seek an emergency approval from the UK MHRA (Medicines and Healthcare Products Regulatory Agency) over the next few weeks.  

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Nomura said that Indian drug regulator, based on feedback from the UK MHRA and the trial results from India (by mid-December all the volunteers in the trial undergoing in India shall receive the two doses of the vaccine), may provide an emergency approval to AstraZeneca's vaccine by end-December or early January 21, as per Serum Institute of India.

"A final approval from India's regulators will follow after additional data are submitted, which is likely later in Q4 FY21 as per the Serum Institute," it said.

Pune-based Serum Institute has exclusive rights to develop and supply the Oxford-AstraZeneca's vaccine in Indian market. The vaccine is relatively cheaper, with large manufacturing capacity, and can be stored at 2-8 degree Celsius, thus allowing the current cold chain infrastructure to handle the product.  

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The emergency approval would limit the procurement by the government for vaccinating sections of the most vulnerable of the population, Nomura said.

Serum Institute has exclusive rights to AstraZeneca's vaccine for 68 countries including India. As per the company, it is prioritising supplies for India's market. The company can prepare around 400 million doses by July 2021 and thereafter can manufacture around 100 million doses per month. "With these production assumptions around 30 per cent of India's population could potentially be vaccinated by end-2021," Nomura said.   

As per Serum Institute, the retail price of the vaccine will be Rs 500 ($6.75) per dose and Rs 1,000 ($13.5) for a two-dose course. The pricing for large volume government procurement will be lower at possibly half the retail price.   

"We expect budgetary allocation by the central government of Rs 20,000 crore in the first year (2021) for procurement of vaccine from the Serum Institute and other developers," it said.  

The other vaccines which are under development and could potentially be approved in the first half of calendar year 2021 are Bharat Biotech's Covaxin, Russia's Sputnik V and ZyCoV-D from Zydus Cadila. 

By Chitranjan Kumar