Shares of Norwegian Cruise Line Holdings Ltd. NCLH, -1.58% slumped 2.6% toward a three-month low in morning trading Monday, after tumbling 18.0% to a two-month low in the previous session, after the cruise operator said it was removing all COVID-19 testing, vaccination and masking requirements from its health and safety protocols. The company said the new protocols, which follows “significant, positive progress” in the public health environment, will be effective Oct. 4. “Health and safety are always our first priority; in fact, we were the health and safety leaders from the very start of the pandemic,” said Chief Executive Harry Sommer. “Many travelers have been patiently waiting to take their long-awaited vacation at sea and we cannot wait to celebrate their return.” The stock’s selloff on Friday followed a hugely disappointing quarterly report from rival cruise operator Carnival Corp. CCL, -3.13% , which sent Carnival’s stock plunging to a 30-year low. Norwegian’s stock has dropped 46.6% year to date, while the S&P 500 SPX, +0.92% has shed 24.2%.