. Malta was still in a desperate state and another convoy (MG1) was run in March 1942. This time, the Italian Navy made a more determined attempt to intercept the convoy, leading to the Second Battle of Sirte. Vian's force of cruisers and destroyers, using threat and concealment by smoke, managed to hold off the Italians while the convoy escaped. The naval action was portrayed as a tactical success against a greatly superior enemy, although the convoy's progress was sufficiently delayed to leave it vulnerable to air attacks and all four transports were sunk and the bulk of the supplies were lost. Despite this, Vian received a personal letter of congratulation from Winston Churchill and he was appointed a Knight Commander of the Most Excellent Order of the British Empire (KBE). In June 1942, Vian's force provided escort for the Operation Vigorous convoy from Haifa and Port Said. This was a part of a sequence of movements but it was rebuffed by strong surface and air forces and returned. After this failed operation, Vian's health deteriorated and he was sent back to Britain in September 1942. During a delay in the journey in west Africa, he caught malaria and was not passed fit for service until January, 1943. In January, he was Mentioned in Despatches for "outstanding zeal, patience and cheerfulness and for setting an example of wholehearted devotion to duty without which the high tradition of the Royal Navy could not have been upheld". Vian's physical condition was now considered to debar him from further sea service and in April 1943 he was appointed to the planning staff for the invasion of Europe. Probably much to his relief, however, this shore job was pre-empted by his return to the Mediterranean to command (from ) an amphibious force for the Allied invasion of Sicily in July 1943. In September 1943, he commanded Force V, a flotilla of escort aircraft carriers providing air support for the Allied landings at Salerno, Italy. Force V comprised the escort aircraft carriers , , and , and the maintenance carrier , acting temporarily as a light fleet carrier. The planned period had to be increased and, when Lieutenant General Mark Clark, commanding the American Fifth Army, requested Force V to stay longer despite fuel shortages, Vian replied: "My carriers will stay here if we have to row back." Vian was twice Mentioned in Despatches; once