London, April 22 : The UK should not expect a "sudden" decline in the number of coronavirus cases and removing the restrictions too soon could lead to a second wave of cases, the government said as the toll crossed 18,000 on Wednesday. As many as 759 deaths were reported since Tuesday, taking the toll to 18,100, while 4,451 more cases took the nation's total to 133,495, as per figures on the Department of Health website. Addressing the daily press briefing, Foreign Secretary Jonathan Rabb, who is standing for Prime Minister Boris Johnson as he recovers from coronavirus, said that lifting the measures too soon risked a second wave of cases and more economic pain. Chief Medical Officer, Professor Chris Whitty, said that social distancing measures could be needed for "quite a long period of time". The development of a "highly effective" vaccine or drug could be the only solution but he warned one was unlikely to arrive in the next calendar year, but an antibody test - could be available in the "pretty near future" Meanwhile, the head of the Army, Gen Sir Nick Carter, who was also present at the briefing, said the military, NHS and government were working on a "very sophisticated" system to distribute more tests and PPE to the front line These plans involved a move to "upscale" mobile testing units, comparable to mobile libraries, he said, adding that doing so was the "greatest logistical challenge" he had ever faced in his 40-year career. /IANS