DHAKA, Bangladesh (AP) — India has tried to fight skyrocketing coronavirus infections by increasing its production of vaccines and banning their export, cutting off supplies to neighbors such as Bangladesh and Nepal as they struggle with surges of their own. These nations have imposed lockdowns as residents of big cities flee to the countryside. Some are also turning to China and Russia for vaccines in a desperate effort to deal with a pandemic that is becoming bigger and deadlier across South Asia. Although new, more transmissible variants appear to be partly behind the surge, experts say other factors are contributing, including large holiday gatherings and fatigue with social distancing and mask wearing.