Does being infected with the zika virus once brings immunity from future infections? if infected again, will a person still be able to infect others?

Not yet known: To my knowledge, we don't yet have answers to these questions. Some mosquito borne viral infections confer lifelong immunity to reinfection, e.g. yellow fever. Others do not, e.g. dengue. In fact second episodes of dengue often are more serious than the first. Research is underway on Zika; keep your antennae up for new information. Excellent info available from CDC: http://www.cdc.gov

Confers immunity: According to the CDC, once a person has been infected with Zika, that person is likely to be protected from future Zika infections. As more research is underway, we are likely to have a broader understanding in the near future. For more information, visit http://www.cdc.gov/zika/.