Nov 22 (Reuters) - The European Union"s drug regulator said on Monday it was evaluating data on booster doses of the COVID-19 vaccine by Johnson & Johnson (JNJ.N) following an application, and a decision could come "within weeks" under a speedy review. The approval sought is for use of a booster dose of the single-shot vaccine, COVID-19 Vaccine Janssen, to be given at least two months after the first dose to people aged 18 years and older, the European Medicines Agency (EMA) said. Faced with surging cases of COVID-19, the European Union has sped up its process for approving boosters and viable treatment options beyond vaccines. Booster campaigns were initially focused on the elderly and those with weakened immune systems. The European Union has so far given mRNA vaccines from the Pfizer-BioNTech (PFE.N), (22UAy.DE) alliance, and Moderna (MRNA.O) the go-ahead as a third booster dose at least six months after a standard two-shot course. It is also considering AstraZeneca"s (AZN.L) booster doses. read more U.S. regulators last week expanded eligibility for booster shots of the Pfizer-BioNTech and Moderna"s COVID-19 vaccines to all fully-vaccinated adults, having previously approved boosters for all recipients of the J&J vaccine. read more Reporting by Pushkala Aripaka in Bengaluru; Editing by Shinjini Ganguli Our Standards: The Thomson Reuters Trust Principles.