dr. tara shrazian says doctors are bracing for likely arrival of the virus. in america, about 4 million women get pregnant each year. >> out of five only one exhibits symptoms. the other four don't have symptoms and may have been exposed but may still develop microencephaly in their fetuses transmission from mom to fetus we think is relatively high. >> nurse practitioner safiyyah okoye is pregnant and decided not to vacation in the caribbean this year. >> even countries that weren't on the travel ban list, i felt like by the time of our trip in march seemed like the list was rapidly growing. >> reporter: today united and american airlines, issued new policies allowing pregnant women to postpone travel or receive full infected countries. the common way zika spreads through mosquito bites and more is needed about risk of transition through sexual contact and blood transfusion. a vaccine could be three to five years away. jon, thank you very much. jon answered question as but zika virus in a facebook chat this evening. you can find his response on our face book

dr. tara shrazian says doctors are bracing for likely arrival of the virus. in america, about 4 million women get pregnant each year. >> out of five only one exhibits symptoms. the other four don't have symptoms and may have been exposed but may still develop transmission from mom to fetus we think is relatively high. >> nurse practitioner safiyyah okoye is pregnant and decided not to vacation in the caribbean this year. >> even countries that weren't on the travel ban list, i felt like by the time of our trip in march seemed like the list was rapidly growing. >> reporter: today united and american airlines, issued new policies allowing pregnant women to postpone travel or receive full refund of flights to zika infected countries. the common way zika spreads through mosquito bites and more is needed about risk of transition through sexual contact and blood transfusion. a vaccine could be three to five years away. jon, thank you very much. jon answered question as but zika virus in a facebook chat this evening. you can find his response on our face book page.

dr. tara shrazian says dodoors are bracing for likely arrival of the virus. in america, about 4 million women get pregnant each year. >> out of five only one exhibits symptoms. the other foururon't have symptoms and may have been exposed but may still develop microencephaly in their fetuses transmission from mom to fetus we think is relatively high. >> nurse practitioner safiyyah okoye is pregnant and decided not to vacation in the caribbean this year. >> even countries that weren't on the travel ban list, i felt like by the time of our trip in march seemed like the list was rapidly growing. >> reporter: today united and american airlines, issued new policies allowing pregnant women to refund of flights to zika infected countries. the common way zika spreads through mosquito bites and more is needed about risk of transition through sexual contact and blood transfusion. a vaccine could be three to five years away. jon, thank you very much. jon answered question as but zika virus in a facebook chat this evening. you can find his response on our face book page.