Despite hopes raised by Pfizer's COVID-19 vaccine, it will take huge efforts for India to defeat the coronavirus, with its 1.3 billion population and the world's second-highest caseload.
Pfizer Inc's Monday announcement that initial trials showed their experimental COVID-19 vaccine was more than 90% effective sparked cheer across the world, scarred by a pandemic that has killed 1.2 million people and infected 50.7 million.
But the Pfizer vaccine needs to be stored at temperatures matching an Antarctic winter - a logistical nightmare for India with heatwaves exceeding 50 degrees Celsius (122°F), few ultra-cold freezers, patchy power and a largely rural population.
"The new two-shot vaccine from Pfizer has to be maintained at minus 80°C - nowhere on the planet does the logistical capacity exist to distribute vaccines at this temperature," said Toby Peters, a professor at Britain's University of Birmingham.
"This is a new challenge to be urgently managed," Peters, an expert in cooling technologies who is studying plans to roll out COVID-19 vaccines, told the Thomson Reuters Foundation.
About 100 drug development teams worldwide are racing to develop coronavirus vaccines, with the hope of distributing them globally on a scale never before witnessed.
The World Health Organization (WHO) estimates about 70% of the global population must be inoculated to end the pandemic.
India will be critical to this effort - with 8.6 million COVID-19 cases, second only to the United States.
The South Asia nation has been scrambling to secure 500 million doses of coronavirus vaccines by July from various manufacturers, in addition to developing its own government-backed COVID-19 vaccine COVAXIN.
India also plans to manufacture up to 200 million doses of candidate vaccines from AstraZeneca Plc and Novavax Inc next year, with funding from the GAVI vaccines alliance and the Bill & Melinda Gates Foundation.
Cold chain
India has a strong record on vaccination, with the world's largest programme distributing 400 million vaccines a year, said Peters.
But nearly half of the leading COVID-19 vaccine candidates need cold storage as low as minus 80°C, researchers say, requiring seamless cold chain distribution from manufacturers to airports to remote villages.
"The success of any COVID-19 vaccination programme will critically depend on robustness of the cold chain," said Peters.
"The key challenge for COVID-19 immunisation will likely be the last mile distribution and ensuring that each vaccination site is equipped with both adequate fixed and outreach cooling equipment to maintain efficacy of the valuable ... vaccine."
He said this would require investment in new cold chain systems and could include innovative approaches like using drones and new mobile rechargeable micro-chillers.
India's health ministry did not respond to requests for comment.
To ease distribution, Pfizer has announced that it will provide a "dry ice pack" container for its vaccines that is able to maintain a temperature of minus 70°C for up to 10 days.
Kiran Mazumdar-Shaw, head of India's biopharmaceutical company Biocon Ltd, which developed a drug to treat patients with COVID-19 complications, voiced concerns over storage of the new vaccine.
"The Pfizer vaccine is unlikely to make its way to India because the ultra-cold chain that it requires ... is something that we may not be in a position to handle," she told CNBC-TV18 television news.
"We might be able to deal with such a cold supply chain in some parts of India, in the cities, but certainly it's not something that will be conducive for India."
She said it was important to watch out for cheaper alternatives to Pfizer's vaccine, which would not need ultra-cold storage and be better suited to cover wider populations.
Other vaccines
Although vaccines could prove a gamechanger for the pandemic, wealthy nations have already bought up more than half the future supply of leading contenders, Oxfam has said.
While India is in talks with Pfizer, according to the financial daily Mint, the United States, Canada, Europe, Japan and Britain have already signed supply deals with the U.S. drugmaker, which aims to make up to 1.3 billion doses in 2021.
"India will not be able to ... get this (Pfizer) vaccine so soon given there are advanced bookings," said Sunil Nair, head of Snowman Logistics, India's largest cold chain services company.
But other potential vaccines, such as those from Johnson & Johnson and Novavax Inc, can be stored at 2 to 8°C, the temperature of a regular refrigerator.
And Randeep Guleria, who is part of the Indian government's COVID-19 vaccine panel, told local media that India's vaccines would be kept at a temperature of minus 20°C.
Nair said storage and transport of vaccines at up to minus 30°C would be "no problem".
"To meet the huge demand that we foresee, (we) will need as many vaccine candidates as possible for use across a range of populations and settings," said Olly Cann, a GAVI spokesman.
