- Summary- Beijing drops key tools of 'zero-COVID' regime- Changes follow historic protests last month- Opening up sparks fears of infection spreadSHANGHAI/HONG KONG, Dec 13 (Reuters) - Chinese leaders have reportedly delayed a key economic policy meeting amid growing signs that COVID-19 infections are surging in Beijing nearly a week after they jettisoned some of the world's toughest anti-virus restrictions.President Xi Jinping and other Politburo members and senior government officials had been expected to attend the closed-door Central Economic Work Conference, most likely this week, to chart a policy course for the embattled Chinese economy in 2023.Long queues are appearing outside fever clinics in a worrying sign that a wave of infections is building, even though official tallies of new cases have dropped in recent weeks as authorities reduce testing.Infections are expected to rise further during the Chinese New Year holiday next month, when people travel across country to be with their families, - a risk for a 1.4 billion population that lacks "herd immunity" after prolonged isolation under lockdowns, and has relatively low vaccination rates among the elderly, according to some analysts.'REALLY ASTONISHING'Experts say China's fragile healthcare system could be quickly overwhelmed if those fears are realised."