In a Pakistan paediatric ward, a chorus of infant coughs and straining lungs is the toll of a frigid winter, compounded by choking smog and lagging vaccination rates. The eastern megacity of Lahore is blanched every winter by smog levels rated among the worst in the world. Rain usually brings respite, soaking up pollution particles, but Pakistan has endured an unusually dry and cold winter -- making children vulnerable to respiratory infection, doctors say. In January alone, more than 18,000 pneumonia cases and nearly 300 fatalities were registered in eastern Punjab province. IMAGES AND SOUNDBITES