COVID Vaccine FAQs: Is Covaxin’s 60% Efficacy Good Enough?
When will it be available? How much will Covaxin cost? Do we know enough about its efficacy and safety yet?
Vaccine-maker Bharat Biotech and Indian Council of Medical Research (ICMR)'s coronavirus vaccine candidate Covaxin is undergoing Phase 3 human trials across 22 sites in India. According to a top official from the company, it will be at least 60 percent effective based on earlier trial results.
When will it be available? How much will Covaxin cost? Do we know enough about its efficacy and safety yet? FIT answers.
What is Covaxin and how is it developed?
COVAXIN, India’s indigenous COVID-19 vaccine by Bharat Biotech, is developed in collaboration with the Indian Council of Medical Research (ICMR) and National Institute of Virology (NIV).
The SARS-CoV-2 strain for Covaxin was isolated in NIV, Pune and transferred to Bharat Biotech. The inactivated vaccine was then developed and manufactured in their High Containment facility in Hyderabad.
An inactivated vaccine or a killed vaccine uses the killed version of the pathogen that causes the disease. They are made from viruses or bacteria that have been killed clinically and therefore cannot cause diseases anymore, according to WHO.
How many people has it been evaluated on?
Phase III trials for the vaccine on 26,000 volunteers from 22 sites in India commenced this month and are yet to conclude. The vaccine has so far been evaluated in 1,000 subjects in Phase I and Phase II clinical trials.
The company has announced that Covaxin is expected to have at least 60 percent efficacy. Can we go by this number?
Some caution must be observed here. Phase III trials for the vaccine began only earlier this month and are yet to conclude. Moreover, the company has not shared the results from its phase 1 or 2 trials either.
So essentially, there is absolutely no publicly available data regarding COVAXIN’s efficacy or safety (except a preprint of an animal study). Bharat Biotech is yet to even share the phase 3 trial’s design.
NITI Aayog member VK Paul, member of the Centre’s expert group on vaccines, told News18 that the data from the earlier trials would be available after completion of phase 3 trials.
What do we know about safety?
According to reports, the company had an adverse event during the phase 1 trial in August when a patient - who had no comorbidities - had to be hospitalised with viral pneumonitis. However, this was not revealed to the public.
“The adverse event during phase I clinical trials during August 2020 was reported to the CDSCO-DCGI within 24 hours of its occurrence and confirmation. The adverse event was investigated thoroughly and determined as not vaccine related,” Bharat Biotech said in a statement.
The company added that it got an approval for the next two phases of clinical trials only after a detailed investigation of the incident was completed.
It is important to note here that AstraZeneca and Johnson & Johnson had temporarily halted their phase 3 trials when adverse events had been reported in trial volunteers.
Is a vaccine with 60 percent efficacy good enough? Where does it stand compared to the candidates made by Moderna and Pfizer?
Earlier this month, US drug manufacturer Pfizer said that its vaccine showed 95 percent efficacy in phase three trials, followed by an announcement by the biotechnology company Moderna, saying its vaccine candidate has 94.5 percent efficacy in phase three trials.
These are based on interim results and the efficacy may come down as the trials are concluded.
Indian officials have said they expect to rely on Covaxin and four other locally-tested candidates to control COVID-19, as they do not expect early access to sufficient quantities of those developed by Pfizer and Moderna - especially because of cold chain requirements to store and transport these mRNA vaccines.
WHO said that any acceptable candidate for the COVID-19 vaccine should ideally have a 50 percent point estimate and a clear demonstration of efficacy. The FDA has also kept a minimum 50 percent efficacy requirement to grant emergency approval to a vaccine.
When will the vaccine be available?
ICMR scientist Rajni Kant expressed hope that Covaxin might be available as early as February, although Bharat Biotech told Reuters on Friday that results of the late-stage trials were expected only between March and April.
How much will Covaxin cost?
The cost of Covaxin will be less than that of a water bottle, according to Bharat Biotech MD, Dr Krishna Ella, says a report by Business Standard. The remark implies that Covaxin will be supplied at a price well below Rs 100.
There isn’t any clarity on the number of doses needed to successfully administer the vaccine regimen.
(The article was first published in FIT and has been republished with permission)
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