By Ahmed Aboulenein and Ankur Banerjee WASHINGTON (Reuters) -U.S. health regulators have authorized injecting a monkeypox vaccine intradermally in adults, meaning between layers of the skin rather than below the skin, in an effort to stretch out low vaccine supplies, the U.S. Food and Drug Administration (FDA) announced on Tuesday. The emergency use authorization for Bavarian Nordic’s Jynneos monkeypox vaccine will increase available doses fivefold as it only uses a fraction of the dose but provides the same protection, health officials said at a White House briefing. The FDA authorization com…