NEW DELHI: The global race to create vaccines against the novel coronavirus has entered a critical stretch, with Pfizer and Moderna releasing very promising final trial data that has raised the hopes of nations struggling to fight the pandemic. Pfizer, which reported 95% efficacy, has now sought early regulatory approval.
Experts have said that vaccines like Pfizer that requires super-cold storage may not be ideal for India and will pose a logistical hurdle. However, India is still in various stages of talks with at least half-a-dozen companies, including Pfizer, to manufacture and procure vaccines for a population of 1.3 billion people. Here are the various vaccine options that provide a ray of hope in the fight against Covid-19 pandemic and how beneficial they could be for India.
Among India’s vaccine deals, the Oxford-AstraZeneca candidate is the most promising.
India’s Serum Institute had entered into a manufacturing partnership with AstraZeneca to produce and supply 1 billion doses of the Covid-19 vaccine.
According to ICMR, the candidate, locally called Covishield, is the most advanced vaccine in human testing in India with Phase 3 trials nearing completion.
Based on the Phase 2/3 trial data, the ICMR had said that the promising results of the trials have given confidence that Covishield could be a realistic solution to the deadly pandemic.
Interim results of the Oxford-AstraZeneca study are expected soon. If successful, it too could begin distributing by the end of the year.
How it works: The Oxford University vaccine is based on a harmless, weakened version of a common cold virus, or adenovirus, that causes infections in chimpanzees. The vector (the carrier) is derived from adenovirus (ChAdOx1) taken from chimpanzees. It is genetically engineered so that it does not replicate in humans.
Pfizer and Moderna
Pfizer-BioNTech and Moderna – both US-based firms – were among the first in the world to announce successful interim results from their large-scale Phase 3 studies.
On Wednesday, Pfizer announced more results in its ongoing coronavirus vaccine study that suggest the shots are 95% effective in normal adults and 94% effective among elderly. It is now planning to seek regulatory nod for emergency use.
Similarly, Moderna Inc’s experimental vaccine was found to be 94.5% effective in preventing Covid-19 based on interim data from a late-stage clinical trial.
A deal with Pfizer or Moderna does not appear to be on the horizon for India, but the Moderna vaccine would be the better option as it can be stored at -20°C in commercial deep freezers. Pfizer’s vaccine, on the other hand, requires storage at minus 70 degrees Celsius or below.
Moreover, as both Pfizer and Moderna are two-dose vaccines, India would need nearly 3 billion doses for its entire population. Neither manufacturer is likely to be able to produce such large quantities anytime soon. However, India said it’s closely monitoring progress and is in talks with all the firms.
How they work: Instead of using the actual Covid virus, both vaccines use its synthetic genetic material, called messenger RNA or “mRNA”, to train the immune system to fight it.
Covaxin is being developed indigenously by Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR).
The potential vaccine was found to be safe without any major adverse events in the first two stages of the trials involving about 1,000 people. The company had said that more than 90% of the participants developed antibodies against the novel coronavirus.
The vaccine has now entered Phase 3 trials with 26,000 participants. It will be the largest clinical trial conducted for a Covid-19 vaccine in India.
How it works: Covaxin has been modelled using an inactive version of the virus (Sars-Cov-2) after isolating a strain of the deadly pathogen from an asymptomatic individual in a containment facility in Hyderabad in May.
India also has a deal with Russia’s Gamaleya Research Institute for its Sputnik V vaccine that claims 92% efficacy although its results have not been peer reviewed or published.
At Tuesday’s Brics summit, Russian President Vladimir Putin suggested that Russia’s Sputnik V vaccine against Covid-19 could be produced in India.
In September, Dr Reddy’s and the Russian Direct Investment Fund (RDIF), Russia’s sovereign wealth fund, entered into a partnership to conduct clinical trials of Sputnik V vaccine and its distribution in India. Dr Reddy will soon start the combined phase 2 and 3 clinical trials of the Russian vaccine in India. The vaccine has to be kept at a temperature of -20 to -70 degrees Celsius.
On August 11, Russia had become the world’s first country to register a coronavirus vaccine, called Sputnik V. The vaccine was developed by the Gamaleya Research Institute, while the Russian Direct Investment Fund (RDIF) is investing in the production and promotion of the vaccine abroad.
How it works: The vaccine is administered in two doses and consists of two serotypes of human adenovirus, each carrying an S-antigen of the new coronavirus, which enter human cells and produce an immune response. It is a so-called viral vector vaccine, meaning it employs another virus to carry the DNA encoding of the needed immune response into cells.
Novavax, with which India has reserved a billion doses, is still in Phase 3 human trials in the UK with 10,000 volunteers.
A larger Phase 3 trial is set to begin in the US this month. If tests are successful, its vaccine may be commercially available in the second half of 2021. In September, Novavax and the Serum Institute of India entered into an agreement to make up to 2 billion doses a year.
How it works: Novavax makes its vaccine candidate by growing harmless copies of the coronavirus spike protein in the laboratory and packaging them into virus-sized nanoparticles.
In July, the Indian vaccine-maker Zydus Cadila began testing a DNA-based vaccine – called ZyCoV-D – delivered by a skin patch. They launched a Phase 2 trial on August 6 and are planning a Phase 3 trial in December.
Zydus Cadila said its Pegylated Interferon alpha-2b, PegiHep, was originally approved for Hepatitis C and was launched in the Indian market in 2011.
Since then safe and efficacious drug use for this product has been demonstrated in thousands of patients, the company said.