The Covid-19 vaccine developed by American biotechnology company, Novavax, is almost 90% effective against the deadly virus, the drug maker has revealed.
Through a press release on Wednesday, it said that results from the final analysis of a pivotal Phase 3 clinical trial of its Covid-19 vaccine candidate conducted in the UK show an overall efficacy of 89.7% with over 60% (half) of the cases caused by the B.1.1.7 (Alpha) variant.
Also, it has a 96.4% efficacy against non-B.1.1.7 (non-Alpha) variants which represents strains most similar to the original virus.
The manuscript published in the New England Journal of Medicine (NEJM), 'Safety and Efficacy of NVX-CoV2373 Covid-19 Vaccine,' provides the final trial analysis, building on an initial interim analysis conducted in January.
The updated analysis announced in March, while additional data from the study was subsequently shared in preprint server medRxiv in May.
"We continue to be very encouraged by data showing high levels of efficacy against even mild disease, and that NVX-CoV2373 (the vaccine) offers strong cross-protection against both the B.1.1.7 (Alpha) variant and non-B.1.1.7 (non-Alpha) variant strains which are widely circulating," said Gregory M. Glenn, president of research and development at Novavax.
"This publication also reinforces the reassuring safety and efficacy profile shown in studies of our vaccine to-date and underscores the potential for NVX-CoV2373 to play an important role in solving this ongoing global public health crisis."
The randomized, observer-blinded, placebo-controlled study, enrolled more than 15,000 adults at trial sites across the UK. The research demonstrated that a two-dose regimen of Novavax' Covid-19 vaccine candidate conferred 96.4% protection against non-B.1.1.7 (non-Alpha) variant strains and nearly 90% protection against all strains in circulation at that time.
It also demonstrated that initial vaccine side effects were mostly mild and transient, and that no imbalance was seen in more serious adverse events compared with the placebo arm. The study assessed efficacy during a period when the B.1.1.7 (Alpha) variant strain of the virus was emerging and circulating widely in the UK and is the same variant that is currently widespread in the US.
"It is quite remarkable how well the vaccine efficacy from our UK trial matches the results seen in the US in the recently released PREVENT-19 trial results, giving even more confidence in the potential role of this vaccine in helping to control the pandemic," said Professor Paul Heath, chief investigator of the Novavax UK trial.
The vaccine awaits approval in India while Taiwan choses it
The vaccine may be cleared for use in India between July and September, which would make it the fifth vaccine in the country, NDTV reported on Wednesday.
It would cost a "low single dollar" price per dose-- but is likely to be costlier than Covishield, the company's CEO Stanley Erck said then.
"We have conducted clinical trials that show that the vaccine works extraordinarily well in phase 3 trials in the UK. And in the US, we are in the last stages of preparing all of the clinical data, the safety data, and now the manufacturing data that has to go into a licensing package,” he said.
He is optimistic that the package will be complete very soon, certainly in the coming quarter.
In the latest development, the company on Friday said that Taiwan has chosen to get the vaccine via the COVAX global sharing scheme, which would add much needed shots to the island's immunisation programme.
Is it effective against Delta variant?
While Novavax has shown 90% effectiveness against Covid, more data is needed to confirm if it will be able to protect against the deadlier Delta variant.
Asked by NDTV, he said: “What we did not show is anything that gets Delta because Delta was not circulating during our trial. So, we don't have those data yet. So, time will tell."
The CEO went on saying: “What we hope, based upon the data that we have against a variety of variances, is that we will have a significant amount of efficacy against Delta. I just can't tell you what that number is yet, because we have not been in the trial where Delta has been circulated."
About the vaccine
The vaccine is being evaluated in two pivotal Phase 3 trials: a trial in the UK that demonstrated efficacy of 96.4% against the original virus strain, 86.3% against the B.1.1.7 (Alpha) variant and 89.7% overall; and the PREVENT-19 trial in the US and Mexico that demonstrated 100% protection against moderate and severe disease and 90.4% efficacy overall.
It is also being tested in two ongoing Phase 2 studies that began in August 2020: A Phase 2b trial in South Africa that demonstrated 55% efficacy overall in HIV-negative participants and 48.6% efficacy against a newly emerging escape variant first described in South Africa, and a Phase 1/2 continuation in the U.S. and Australia.
NVX-CoV2373 is stored and stable at 2°- 8°C, allowing the use of existing vaccine supply chain channels for its distribution. It is packaged in a ready-to-use liquid formulation in 10-dose vials.
