Oct 19 (Reuters) - Johnson & Johnson (JNJ.N) on Tuesday reported lower-than- expected quarterly revenue after sales of its COVID-19 vaccine missed Wall Street estimates following a string of production setbacks. The New Brunswick, New Jersey-based company maintained its 2021 sales goal of $2.5 billion from the vaccine, and said it recorded $766 million in sales of the shot in the first nine months of 2021 - which indicates that sales will have to more than triple in the fourth quarter to meet its forecast. "We"re still very much committed to the $2.5 billion of revenue and the supply that is correlated to that," Chief Financial Officer Joseph Wolk told investors on a conference call. The drugmaker earlier this year experienced quality problems at a Baltimore manufacturing facility that produces the single-dose vaccine, resulting in wastage of millions of doses. The J&J shot, once touted an as important tool for vaccinating hard-to-reach areas, is behind its schedule for deliveries in the United States and Europe. The vaccine has the lowest uptake in the United States at a time when rivals Moderna Inc (MRNA.O) and Pfizer (PFE.N) are signing up supply deals for booster doses in 2022 and beyond. "It"s hard to say if J&J will meet that target or not, but with the booster guidance coming out soon, that could provide a boost to the fourth quarter," Edwards Jones analyst Ashtyn Evans told Reuters. The U.S. Food and Drug Administration (FDA) has yet to authorize a booster dose of the J&J vaccine, with a decision expected in the coming days. J&J"s shares rose nearly 2% in morning trade, reversing a premarket fall, as the company raised its overall adjusted profit forecast and beat earnings estimates. Sales in its medical devices unit rose 8% to $6.64 billion but missed analyst estimates of $6.87 billion, hurt by a resurgence in COVID-19 cases due to the Delta variant. Excluding items, J&J earned $2.60 per share, beating expectations of $2.35 per share, according to Refinitv data. J&J lifted its 2021 forecast for adjusted earnings per share to between $9.77 and $9.82, from its prior estimates of $9.60 to $9.70. Overall sales of $23.34 billion missed expectations of $23.72 billion. COVID-19 vaccine sales of $502 million missed estimates of $815 million, according to FactSet. Reporting by Manas Mishra in Bengaluru; Editing by Will Dunham and Arun Koyyur Our Standards: The Thomson Reuters Trust Principles.