PARIS: With a strategic alliance, 24-hour production and a bit of luck, Pfizer and BioNTech were able to roll out their Covid vaccine at a brisk pace and relatively free of controversy.

US pharmaceutical giant Pfizer and BioNTech, a smaller German biotech firm, joined forces on April 9, 2020, as the world reeled from the pandemic, with deaths soaring and nations under lockdown.

The companies set an ambitious goal: Producing hundreds of millions of jabs in 2021 -- an incredibly short timeline when vaccines usually take years to develop and secure regulatory approval.

Seven months later, Pfizer announced promising results from clinical tests showing the vaccine developed by BioNTech was 90-percent effective against the novel coronavirus.

The shot -- using the hitherto unproven mRNA method to deliver vaccines -- has since proven a success in public rollouts across the world.

In March, BioNTech even promised 2.5 billion doses this year, a quarter more than initially planned.

The vaccine currently plays a leading role in European vaccination campaigns and in the United States.