Paris - Fierce rivals normally, the Covid-19 crisis has led pharmaceutical companies to join forces to work together to produce the billions of vaccines needed globally.
The latest tie-up involves US giant Merck which agreed to help produce the potentially key one-shot vaccine developed by Johnson & Johnson.
- Who's working with who? -
It became clear very shortly after the coronavirus first surfaced in China in late 2019 that it was going to present a major challenge to a world without a vaccine or treatments to help the millions worst affected.
At the height of the first wave in April 2020, France's Sanofi teamed up with British peer GSK to develop a vaccine based on one of its molecules combined with its partner's adjuvant, a booster to strengthen the inoculation.
Factfile on the Johnson & Johnson vaccine
This jab however ran into testing problems, compounded by huge political pressure for the French government to deliver a comprehensive and speedy vaccination campaign.
The shot is now only expected to be available later this year, with another perhaps to follow in early 2022.
Sanofi meanwhile announced earlier this year that it would help US rival Pfizer to make its vaccine -- itself the product of a joint effort with Germany's BioNTech -- in the next few months.
The Pfizer/BioNTech inoculation was the first to be widely authorised for use and has proved to be very effective.
Sanofi has also explored working with Johnson & Johnson on joint production in Europe.
Other alliances of this type have multiplied, such as between Swiss giant Novartis and Pfizer-BioNTech, and Bayer, which will produce the vaccine developed by German biotech CureVac which is also working with GSK.
On Tuesday, US President Joe Biden announced Merck had agreed to help produce the shot developed by Johnson & Johnson, describing it as the "type of collaboration between companies we saw in World War II."
WHO urges collaboration to speed up Covid-19 vaccinations (Feb 4)
- Who does what? -
While the deals ramp up, it is clear that the unlikely cooperation also has its limits.
The companies which have developed vaccines, such as Pfizer/BioNTech or Johnson & Johnson, fully intend to guard their crown jewels -- the scientific formulation of each jab developed in some cases through over many years and at considerable cost.
Bayer, Merck, Novartis and Sanofi will be involved in the last stages of the process, checking and then packing the vaccines into vials for use.
This stage, still absolutely crucial to the safety and effectiveness of the jabs, presents considerable technical challenges, especially for the new generation mRNA messenger shots developed by Pfizer/BioNTech and Moderna.
The new generation mRNA vaccines
- Rationale for tie-ups -
The companies involved in these tie-ups all have their own reasons, not least their own interest in staying in the fight and keeping up with their rivals in what everyone agrees is an unprecedented global health crisis.
Sanofi for example continues to work on its own vaccines even as it helps out others while Merck, working with France's prestigious Pasteur Institute dropped its shot after it was shown to be ineffective against the coronavirus.
Bayer and Novartis meanwhile are not vaccine specialists, with the Swiss company having quit the field several years ago.
By Julien Dury