German firm BioNTech said Monday that the Covid-19 vaccine it developed with Pfizer does not require any modifications at the moment to protect against variants of the virus.

"To date, there is no evidence that an adaptation of BioNTech's current Covid-19 vaccine against key identified emerging variants is necessary," the company said in a statement.

Nevertheless, in preparations for a need at some point to make tweaks to its current vaccine, the company said it began tests in March on a "modified, variant-specific version" of its jabs.

"The aim of this study is to explore the regulatory pathway that BioNTech and Pfizer would pursue if SARS-CoV-2 were to change enough to require an updated vaccine," it said.

An assessment is also ongoing on the impact of a possible third dose in prolonging immunity and in protecting against variants.

BioNTech chief executive Ugur Sahin had said in April that the vaccine works against the Indian variant.

The BioNTech/Pfizer vaccine was the first to win authorisation in the West, and has since been deployed in dozens of countries worldwide.

It is now supplying more than 90 countries worldwide, and is expecting to ramp up its production to up to three billion doses by the end of the year from 2.5 billion doses expected previously.