Through mosquito bites,
From mother to child,
Through sexual contact,
Through blood transfusion.
"... Anyone who lives in or travels to an area where Zika virus is found and has not already been infected with Zika virus can get it from mosquito bites. Once a person has been infected, he or she is likely to be protected from future infections. ..."
What is the incubation period? Surely the window of contagion is fairly small -- a few weeks?
Considering Zika is rarely ever deadly (has anyone died from it yet?), what is the point of a vaccine? Just give everyone the disease (excluding pregnant woman of course).
Through mosquito bites, From mother to child, Through sexual contact, Through blood transfusion.
"... Anyone who lives in or travels to an area where Zika virus is found and has not already been infected with Zika virus can get it from mosquito bites. Once a person has been infected, he or she is likely to be protected from future infections. ..."
http://www.cdc.gov/zika/transmission/