July 21 (Reuters) - Pfizer Inc and BioNTech SE on Wednesday said they had struck a deal for South Africa's Biovac Institute to process and distribute over 100 million doses a year of their COVID-19 vaccine for the African Union beginning in 2022.

Technical transfer, on-site development and equipment installation activities will begin immediately, they said. Biovac, a public-private partnership focused on vaccine production, will receive COVID-19 vaccine drug substance made in plants in Europe, and will begin so-called fill-finish operations, the last stage of drug manufacturing and packaging, in 2022.

Pfizer announced the partnership ahead of a speech by Chief Executive Albert Bourla at a World Trade Organization (WTO) Summit.

WTO members have been in talks for months on waiving drug firms' intellectual property (IP) rights for COVID-19 vaccines. Most developing countries support the waiver but several wealthy countries remain strongly opposed, saying it will deter research that allowed COVID-19 vaccines to be produced so quickly.

In his prepared remarks, Bourla made a plea for the group to maintain the current IP rules.

"Weakening IP rules will only discourage the type of unprecedented innovation which brought vaccines forward in record time and make it harder for companies to collaborate going forward," Bourla said.

Last month, the World Health Organization said it was setting up a hub, or training facility, in South Africa to give companies there the know-how and licenses to produce COVID-19 vaccines. Biovac was one of the initial participants in the hub.

Biovac has partnered with Pfizer since 2015 to manufacture and distribute its Prevenar 13 pneumonia vaccine. (Reporting by Michael Erman; editing by Richard Pullin)