Dec 16 (Reuters) - The EU drugs regulator approved increasing the manufacturing capacity of COVID-19 vaccines from Johnson & Johnson (JNJ.N), Moderna (MRNA.O) and Pfizer/BioNTech (PFE.N), (22UAy.DE) as Europe gears up for the fight against the Omicron variant. Several European countries are battling soaring COVID-19 cases, even as regulators debate over the efficacy of vaccines against the fast-spreading variant. The European Medicines Agency (EMA) said on Thursday it had approved an additional manufacturing site for Johnson & Johnson"s Janssen vaccine in Marcy-l"Étoile, France. The manufacturing site is operated by Sanofi Pasteur, which will make the finished product. The regulator also gave the nod for increasing production of Moderna"s Spikevax shot at the manufacturing site in Madrid, which is operated by ROVI Contract Manufacturing. This will allow for the production of around 25 million additional Spikevax doses every month for the European Union and other countries through the COVAX initiative. The production of an active substance for Pfizer/BioNTech"s COVID-19 vaccine will be increased at the Andover, Massachusetts site operated by Wyeth Pharma, EMA said.