By Lena H. Sun and Brady Dennis -The Washington Post • Sunday February 14, 2016 Global health authorities and government officials are mobilizing to battle the fast-spreading Zika virus, sending rapid-response teams to affected regions, issuing travel warnings for pregnant women, accelerating vaccine trials and even deploying mosquito-fighting troops to hard-hit areas in Brazil. Stung by criticism that the world's response to the Ebola epidemic was halting and disjointed, officials in Latin America, the United States and Europe say they are determined to do better against a new foe that, in some ways, is more daunting than the hemorrhagic virus that killed 11,000 people in West Africa. But their efforts are being hobbled by a fundamental lack of understanding of the disease that has spread to nearly three dozen countries and is moving so quickly that some experts estimate it could infect as many as 3 million to 4 million people within 12 months. Unlike the highly lethal Ebola, which