‘Efficacy 67%’: Zydus seeks nod for vaccine
Drugmaker Zydus Cadila said on Thursday it has applied for emergency use approval of its three-dose Covid-19 vaccine candidate, which has shown an efficacy rate of 66.6% in an interim analysis of its phase 3 trials.
The company said that this is the first coronavirus vaccine using a DNA plasmid in advanced trials, and the first in India to be tested in a large group of adolescents. If approved, it will be India’s second home-grown vaccine, and the fifth overall to be cleared for use in the country after Covishield, Covaxin, Sputnik V and Moderna.
“As the first ever plasmid DNA vaccine for human use, ZyCoV-D has proven its safety and efficacy profile in our fight against COVID-19. The vaccine when approved will help not only adults but also adolescents in the 12 to 18 years age group,” said Sharvil Patel, managing director of Cadila Healthcare, in a statement by the company.
The clinical trials included 28,000 people who were split into two groups that either received the vaccine or a placebo. Among them were 1,000 volunteers in the 12-18 age group. The company has not yet released data from its previous phases.
It also announced that the vaccine worked as well as a two-dose regimen as it did in the three-dose formulation that it was tested in, and data pertaining to that has been submitted to the regulator for scrutiny.
Zydus, which aims to produce up to 120 million doses annually, said its study coincided with the peak of India’s second wave of infections and affirmed its efficacy against mutations, especially the Delta variant. It did not, however, disclose its efficacy against those variants.
According to the company, the tolerability profile among the adolescents was similar to what was seen in the adult population. Primary efficacy of 66.6% was attained for symptomatic RT-PCR positive cases in the interim analysis.
The company said there were no moderate cases of Covid-19 in the vaccine arm, though it did not disclose how many cases the interim analysis was based on.
“We are making constructs for variants for future upgrade, if needed. Interim data has been submitted, and we will submit more data as it gets analysed to the regulator in due course. We haven’t reported any major side-effects for the vaccine. In fact, side-effects are similar to the placebo arm,” said Patel.
Patel added that the vaccine candidate has exhibited robust immunogenicity, and tolerability and safety profile in the adaptive phase 1/2 clinical trials carried out earlier.
On pricing, the executive said no discussions had taken place but added that this will be discussed once regulatory approvals are in place and will depend on doses, technology, etc.
ZyCoV-D is an intradermal vaccine that can be applied using a needle-free applicator, which could help significantly reduce side effects.
The vaccine is stored at 2-8°C but has shown good stability at temperatures of 25°C for at least three months, the company said.
Experts say an efficacy rate of 66.6% is “decent”. “As per WHO threshold, 50% and above efficacy is approved for a respiratory vaccine,” said Dr GC Khilnani, former head of pulmonology department, All India Institute of Medical Sciences, Delhi.
The company has not begun stockpiling the vaccine, as it is currently in the process of putting together a new production facility that is likely to be up and running by July end.
“We are currently in the scale-up phase. We could produce 5 crore (50 million) doses by December, with production likely to start by mid August or early September. Afterwards we plan to have a sustained production of 1-1.2 crore (10-12 million) vaccine doses per month,” said Patel.