NEW YORK, Oct 7 (Reuters) - Both supply side and demand side factors are contributing to U.S. inflation right now, but most of the current price changes may be driven by pandemic-related shifts that could subside over time, Cleveland Federal Reserve Bank President Loretta Mester said on Thursday. An increase in medium and long-term inflation expectations, paired with a continued rise in inflation, could be a sign that the changes are being driven more by higher demand than by supply-side disruptions, said Mester, speaking during a panel organized by the European Central Bank. However, that is not her baseline forecast, she said. (Reporting by Jonnelle Marte) Our Standards: The Thomson Reuters Trust Principles.