BERLIN, June 30 (Reuters) - Germany plans to spend 3.9 billion euros on 204 million vaccine doses for next year to guard against production bottlenecks and have ample provision for any new COVID-19 variants that might emerge or the need for booster shots.

Of the planned expansion, nearly 85 million doses of BionTech/Pfizer's mRNA vaccine are already contracted for via the European Union's procurement scheme, according to a health ministry paper seen by Reuters.

The paper said at least one other mRNA-type vaccine should be procured, as well as vaccines using other technologies, to help guard against production bottlenecks.

"It makes sense given the precautionary principle to buy further vaccines to for protection against mutations and for refresher campaigns in order to cover for production fall-outs or other unforeseen circumstances," the ministry wrote.

The Robert Koch Institute, the country's public health agency, had advised that there should be sufficient mRNA vaccine available to fully cover the country's needs, but that alternative technologies should also be bought in case of unforeseen problems with the latest vaccine technology.

A further 31.8 million doses will be in the form of Moderna's mRNA vaccine. Johnson & Johnson's vector vaccine will contribute 18.3 million doses, and a total 70 million doses of vaccines from Sanofi, Novavax and Valneva will contribute the rest.

Vaccines made by AstraZeneca, which had difficulties delivering to the EU supplies of its vaccine that it had contracted for this year, and by Curevac, whose vaccine posted disappointing trial results, were not mentioned. (Reporting by Andreas Rinke, Writing by Thomas Escritt, Editing by Franklin Paul and Alison Williams)