COVID-19 vaccine: Where some of the most promising trials stand

In India, while two vaccine candidates are in phase 2 trial, one has entered phase 3.
COVID-19 vaccine updates
COVID-19 vaccine updates
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With just over two months left for the year to end, we are nearing several deadlines for COVID-19 vaccine trials. Trials for multiple indigenous as well as foreign vaccine candidates are going on in India, with institutes like National Institute of Virology (NIV), Indian Council of Medical Research (ICMR), and Serum Institute of India (SII) being involved with private players to run clinical trials. Here’s where some of them stand so far.

Bharat Biotech’s COVAXIN: Hyderabad-based Bharat Biotech’s COVAXIN had successfully finished phase 1 trials in September with positive results showing an “encouraging safety profile.” According to latest reports, Bharat Biotech, which is trialling COVAXIn with ICMR and NIV, has halved the size of its phase 2 trials to test only 380 volunteers.

Earlier the total number of volunteers for phase 1 and phase 2 was decided to be 1,125 candidates, of which 375 volunteers were involved in phase 1. In phase 2 trials, the pharmaceutical company will also test on children above the age of 12, as compared to phase 1, when COVAXIN was administered to only adults. According to Gagandeep Kang, professor at Christian Medical College, Vellore, the reason behind halving the phase 2 trials was the good immunogenicity data obtained from phase 1, which allowed the company to shorten phase 2, with the aim to expedite phase 3 after getting regulatory approval.

Zydus Cadila’s ZyCoV-D: Ahmedabad-based Zydus Cadila’s ZyCoV-D vaccine trials are on track and are in phase 2. This is the second indigenous vaccine the clinical trials of which are being done in India. In the phase 1 trials, the results showed favourable safety, immunogenicity and tolerability. An independent Data Safety Monitoring Board also endorsed the safety of the vaccine in phase 1, after participants were observed for seven days and the vaccine was found to be very safe, the company has said.

Oxford-AstraZeneca vaccine: Drugmaker AstraZeneca along with Oxford University is running clinical trials for ChAdOx1-S, which is a viral vector vaccine. In India, the makers have tied up with SII and are running the trials which are in phase 3. This candidate is one of the frontrunners for a COVID-19 vaccine globally. The results of the phase 3 trials in India, which are being done in cities including Pune, Bhubaneshwar and Chandigarh, are expected in November-December.

According to latest reports, Dr Suresh Jadhav, executive director of SII, has said that India may get a COVID-19 vaccine by March 2021, given that two candidates in India are in phase 2 trials and one – the Oxford-AstaZeneca candidate – is in phase 3 trials.

Chinese vaccine candidates: One of China’s top coronavirus vaccine candidates by China National Biotech Group has reportedly shown positive results in the latest clinical trial. Named BBIBP-CoV, the vaccine is being developed by the Beijing Institute of Biological Products, a CNBG subsidiary. It is one of the 10 vaccine candidates in the world that has now entered phase 3 trials, and one of three that are in this phase in China, according to the World Health Organisation. CNBG is offering its vaccine free to students who study abroad in a strategy that health experts say raises safety and ethical concerns.

Further, China is rapidly increasing the number of people receiving its experimental coronavirus vaccines, with a city offering one to the general public and a biotech company providing another free to students going abroad. Jiaxing, which is located south of Shanghai, is offering a vaccine under development by Sinovac, it said in an announcement Thursday. It said high-risk groups, including people who are responsible for the basic operations of the city will receive priority, but that residents who have emergency needs can also sign up. The vaccine is in the final stage of clinical testing, but has not yet been approved. 

Top Chinese health officials have promised a vaccine for the general public before the end of this year.

Russian vaccine Sputnik V: Vaccine candidate Sputnik V has been developed by the Gamaleya National Research Center of Epidemiology and Microbiology and the Russian Direct Investment Fund, Russia’s sovereign wealth fund in Russia. Dr Reddy's Labs on Saturday announced that they have received approval from the Drug Control General of India to conduct an adaptive phase 2 and 3 clinical trial for Sputnik V vaccine in India. The Hyderabad-based drug maker said in a press release that this will be a multi-centre and randomised controlled study, which will include safety and immunogenicity study. Dr Reddy's had, on October 13, reapplied to the Drugs Controller General of India (DCGI) seeking permission to conduct combined phase 2 and 3 human clinical trials in the country.

In its revised protocol, the firm had stated earlier that the phase 2 trial would include 100 subjects, while the phase 3 would involve 1,400 volunteers, sources had said. The Indian pharma giant has collaborated with The Russian Direct Investment Fund (RDIF) to conduct clinical trials of the Sputnik V vaccine as well as its distribution. Upon regulatory approval in India, RDIF shall supply to drug maker Dr Reddy's 100 million doses of the vaccine, the firm had said last month.

Moderna’s mRNA-1273 vaccine: The Massachusetts-based company announced that it had entered phase 3 trials in July while continuing to observe results from phase 2. Preliminary results were positive wherein volunteers, including the elderly, produced coronavirus antibodies. Moderna hopes to deliver 500 million doses per year starting 2021 and has signed a deal with Swiss manufacturer Lonza to enable it to make a billion doses a year.

In the latest update, Moderna said it is talking to international regulators to expedite approval for the vaccine. In Canada for instance, to speed things up, mRNA-1273’s progress will be reviewed by the country’s health regulator real-time, which could potentially reduce the time for authorising the vaccine as researchers can submit efficacy and safety results as they get them rather them studying them at the end.

Pfizer vaccine: Drugmaker Pfizer in collaboration with German partner BioNTech SE is working on their own COVID-19 vaccine candidate. Pfizer said on Friday that it may seek authorisation for using the vaccine in emergency cases in late November in the US. This will likely be filed, Pfizer said, as soon as safety data becomes available. The Food and Drug Administration had said earlier in October that it would require at lease two months of safety data on half of the volunteers of a trial before authorising emergency use.

While there are many vaccines that are being tested and it is likely that we may have a viable candidate by 2021, WHO has said that healthy people may have to wait till 2022 to get it as health workers and those with a higher risk of contracting the infection will be prioritised.

Addressing an online question and answer session on Friday, WHO's chief scientist Soumya Swaminathan said there would be at least one effective vaccine by 2021 but it would be available “only in limited quantities”.

“Most people agree, it's starting with healthcare workers, and frontline workers, but even there, you need to define which of them are at highest risk, and then the elderly, and so on,” Swaminathan said on prioritising who gets the vaccine first. “There will be a lot of guidance coming out, but I think an average person, a healthy young person might have to wait until 2022 to get a vaccine.”

(With PTI inputs)

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