Three pharmaceutical giants have claimed that their COVID-19 vaccines can be 90% and above effective — Pfizer-BioNTech (95% effective), Moderna Therapeutics (94.5% effective) and now, Oxford-AstraZeneca (90% effective under one dose regimen and 70% with two-dose regimen). Among the three candidates, the vaccine developed by Oxford-AstraZeneca seems to be viable and good news for India, predominantly because of its cold storage conditions and affordability. “This vaccine can be easily administered in existing healthcare systems, stored at ‘fridge temperature’ (2 to 8 °C) and distributed using existing logistics,” said Oxford University. This, according to experts, is a game-changer.
While Pfizer’s vaccine needs ultra-cold storage conditions of minus 70 degree Celsius for up to five days, Moderna’s vaccine can be stored at minus 20 degree Celsius and can remain effective for up to six months. AstraZeneca’s vaccine, on the other hand, can be stored, transported and handled at normal and standard refrigerated conditions of 2 to 8 degree Celsius for at least six months. So, the vaccine can be stored in ordinary refrigerators and does not require a freezer. “This means they can be easily distributed using existing medical facilities such as doctor's surgeries and local pharmacies, allowing for the vaccine, if approved, to be deployed very rapidly,” said AstraZeneca.
Notably, the success of a vaccine depends on the cold storage conditions and is crucial for a country like India, where infrastructures such as roads and electricity play a critical role in maintaining the potency of the vaccine until it is administered to individuals, even in outlying areas. “Getting vaccines to remote communities isn’t enough. If at any stage, the temperature of the vaccine drops below two degrees or rises above eight degrees, it can become unusable,” said the international humanitarian aid organisation, United Nations Children's Fund (UNICEF), in its blog on 'In photos: How vaccines reach the most remote places on earth'.
In an interview to journalist Karan Thapar for The Wire, Gagandeep Kang, professor of microbiology at the Wellcome Trust Research Laboratory, Christian Medical College, Vellore, said, AstraZeneca vaccine fits well for India. “Most vaccines we use are held at 2-8 degree Celsius; there may be shelf space challenges, but the storage temperatures are appropriate for India,” she said.
Polio drops are one of the most successful vaccines in the country as it does not have to be stored in the minus 20 or minus 80 degree Celsius freezer. It can be stored between 2 and 8 degree Celsius for six months. “Some villages in Arunachal Pradesh, which can be accessed after two days of walking, get polio drops. But, if the requirement is minus 80 degree Celsius, how do you get it to a place that does not have a freezer? If it has to be transported by walking to a remote village for two days, how can it be kept in the required cold condition? An ice pack can work, but it is not ideal,” said Dr Pavithra Venkatagopalan, a biotechnologist in Chennai and the Director of Care Health Diagnostic Center, told TNM.
It is like transporting ice-cream. “The ice-cream will not taste the same once it melts and is refrozen,” said Dr Pavithra, explaining the role of road accessibility.
Vaccines require a robust cold chain, which is the temperature conditions under which it is maintained throughout the supply chain — from manufacturing until it is administered — to ensure its efficacy.
Metro cities like Mumbai and Chennai have advanced power infrastructure and don’t have frequent and prolonged power fluctuations. In rural, tier two and three areas, power fluctuation is more frequent. “Vaccines are supposed to be stored at a specific temperature and voltage. But, during a power outage, there is a temperature change, which, in turn, makes it challenging for vaccines to remain effective,” said Dr Pavithra, who did her PhD (Doctor of Philosophy) on coronaviruses.
Elucidating her point with an example, she said, “If I have to take my son for a vaccine, I would rather take him to a multi-speciality hospital rather than a clinic, even though it is the same doctor in both the places; because the former is likely to have a generator for the fridge and the vaccine will be in the ideal condition possible.”
Pfizer’s vaccine may work in places with strong infrastructures, like an IIT or the Tuberculosis Research Centre (TRC). But these have to be available in Primary Healthcare Centres (PHCs), which have functional refrigerators, too, if it has to reach every corner of the country. “That is why the vaccine by AstraZeneca could make a huge difference for the people of India,” said Dr Pavithra, adding, “India has the best vaccine administering system in the world. Imagine giving polio drops to 1.3 billion people; we have achieved it.”
Incidentally, Adar Poonawala’s Pune-based Serum Institute of India (SII) has partnered with AstraZeneca and has already manufactured 400 million doses of Covishield vaccine for India. Meanwhile, the Union government is still examining the cold-chain requirements to procure vaccines by the other pharma companies.
Dr Amit Dutt, a scientist at Tata Memorial Centre Advanced Centre for Treatment Research and Education in Cancer, wrote on Twitter: "As expected, COVISHIELD appears to be equally effective! Its storage is similar to other traditional vaccines like BCG (between 2-8°C) and likely to be fivefold less expensive ~ Rs 1K/individual. If it meets the statutory guidelines in India, it's going to be a game-changer!"
As expected, COVISHIELD appears to be equally effective! Its storage is similar to other traditional vaccines like BCG (between 2-8°C) and likely to be fivefold less expensive~ Rs 1K/ individual. If it meets the statutory guidelines in India— it's going to be a game-changer!
— Amit Dutt (@dutt_lab) November 23, 2020
Although Pfizer said it is designing “temperature-controlled thermal shippers”, which uses dry ice to maintain temperature conditions of -70°C, it could add to the cost of the vaccine. Currently, the American pharmaceutical company has priced it at $20 (Rs 1,479), while Moderna vaccine is priced at $33 (Rs 2,440) per dose. What makes the Oxford-AstraZeneca vaccine work in favour of India is its affordability, as it has been priced at $4 (approximately Rs 295) per dose.
"Compared to Pfizer vaccine, Moderna vaccine is better-suited for the cold-chain we have, but expensive. However, India has never had a vaccine where we have paid more than $3 per dose, said professor Gagandeep Kang.
Dr T Jacob John, virologist and former professor at CMC Vellore, views Oxford-Astrazeneca’s vaccine as almost a bird in the hand. “It is already being manufactured in millions in India, it is affordable, the cold storage condition is ideal,” he said. “However, what needs to be spelt out next is a national policy and action plan. Apart from PHCs, how will these vaccines be transported and delivered to remote areas, who will bear the expenses? As of now, the government has only identified priority groups who will first receive the vaccine.”
In an effort to establish a strong cold supply chain, a national expert group, in October, had said that it was approaching public and private sector entities in the pharma, food processing sector, agro-businesses and food delivery start-ups (Zomato and Swiggy) to identify fridges and cold storages at the taluk-level to store and distribute the vaccines.
On Friday, Prime Minister Narendra Modi said, “Database, cold chain augmentation and transportation mechanisms are being readied, with a digital platform for vaccine delivery and monitoring being prepared and tested in consultation with all stakeholders.”