Global pharmaceutical companies rose to the challenge when the world was in the grip of the Covid-19 pandemic early last year, working at breakneck speed to develop vaccines to eradicate the disease.
Now, another challenge has emerged, one that would appear less easy to surmount: Manufacturing the massive quantities of doses required to vaccinate the entire planet.
"One-and-a-half years into the Covid-19 pandemic, one key element to single out is speed," said Professor Leo Yee Sin, executive director of Singapore's National Centre for Infectious Diseases.
"The virus mutates and changes its characteristics, as demonstrated by the Delta variant, leading to successive waves of infection, which was unexpected. To stay ahead of the virus, humans need to speed up vaccine production and implementation and continue to monitor the virus, so that vaccine development can keep pace," she told The Straits Times.
The problems thwarting swifter production of vaccines range from vaccine nationalism by major producing countries to a shortage of key raw materials.
Countries have relied on legislation - such as the United States with its Defence Production Act (DPA) - to safeguard their own supplies, which makes the task of securing vaccines, as well as the raw materials, an onerous one for others.
World Health Organisation (WHO) spokesman Tarik Jasarevic told ST: "Supplies have been negatively impacted by the use of the DPA. Allowing raw materials to be exported will alleviate some of the constraints involved in the production of Covid-19 vaccines."
Furthermore, with more than 100 components and ingredients required for vaccine production, pharmaceutical companies are engaged in stiff competition with one another to build the supply chains required to ensure steady output of their doses.
A fledgling effort to waive patents for the life-saving Covid-19 vaccines has also lost steam, even though it would have allowed more manufacturing facilities worldwide to be involved in their production.
Nevertheless, WHO director-general Tedros Adhanom Ghebreyesus remains an outspoken advocate for a waiver of the Agreement on Trade-Related Aspects of Intellectual Property Rights on Covid-19 tools.
Mr Jasarevic said: "This is to ensure security of supply through diversification of global manufacturing capacity for vaccines and other diagnostics and treatments related to the Covid-19 pandemic."
The vaccines using newly developed mRNA technology, in particular, face significant hurdles when it comes to ramping up production, given that manufacturing capacities need to be built from scratch.
Given the novel nature of the mRNA technology, few contract manufacturing organisations have the technical know-how and size to partner firms like Moderna, Pfizer and BioNTech.
Even in the case of protein sub-unit vaccines, such as the one developed by Novavax, the requirement for huge amounts of proprietary materials could play spoiler to faster production.
Viral-vector vaccines present their own set of challenges: Given that human cell growth is unpredictable, this has posed the problem of low yields of cell culture, which has affected a Johnson & Johnson production site in Europe.
In the case of inactivated virus vaccines such as Covaxin, developed by India's Bharat Biotech, one of the speed bumps appears to be a lack of qualified personnel to make a product of the highest standard, though insufficient raw materials are also a factor hindering output.
Another problem looms for pharmaceutical companies, namely a lack of fill-and-finish capacity - the final stage, in which the vaccines are bottled - for the billions of doses they have promised.
Mr Jasarevic summed up the need of the hour: "We need an additional 250 million doses by September, with 100 million in June and July, to vaccinate at least 10 per cent of the population of every country by the end of September, and additional doses to achieve at least 30 per cent by the end of the year."
Referring to Covax, a global initiative aimed at equitable access to Covid-19 vaccines for poorer countries, he said: "If countries immediately share doses with Covax and if manufacturers prioritise Covax orders, we can vaccinate at least 10 per cent of the population of every country by September, and at least 30 per cent by the end of the year."
He added: "Expanding production globally would make low- and middle-income countries less dependent on multinational companies and foreign aid."