The World Health Organization (WHO) said Monday that 172 countries are engaged with its COVAX Global Vaccines Facility, which it describes as the most extensive and diverse COVID-19 vaccine portfolio in the world.

COVAX is the vaccines pillar of the Access to COVID-19 Tools or ACT Accelerator, a global collaboration launched by WHO to accelerate development, production, and equitable access to COVID-19 tests, treatments, and vaccines.

“At present, there are nine vaccines that are part of this dynamic portfolio, which is constantly being reviewed and optimized to ensure access to the best possible range of products,” WHO Director-General Tedros Adhanom Ghebreyesus told a bi-weekly press webinar on the development of vaccines to counter the virus.

He said there are four more producers and a further nine vaccines under longer-term evaluation.

The WHO chief said that the COVAX facility is crucial for joint procurement and pooling risk across multiple vaccines so that all countries signed up will have access to a safe and effective vaccine.

“This is in the interests of all countries, even those that have invested with individual manufacturers independently,” said Tedros.

Global competition for vaccine doses could trigger a spiking of prices exponentially compared to a collaborative effort such as the COVAX Facility, he warned.

“Vaccine nationalism only helps the virus,” said Tedros.

The WHO head declined to say which countries are inside or outside the ACT Accelerator.

On Aug. 18, according to the WHO website, the list of those who have so far committed to the ACT Accelerator is: Austria, Belgium, Canada, France, Germany, Italy, Mexico, Morocco, New Zealand, Norway, Saudi Arabia, South Africa, Spain, the UK, and the European Commission.

China, Russia, and the US have not been named part of it.