Scientists say the Zika virus may be a threat to women throughout their pregnancy, and not just in the first trimester as previously thought.
The revelation comes as the Center for Disease Control (CDC) in the United States has asked Congress for millions of dollars to fight the virus.
"Everything we look at with this virus seems to be a bit scarier than we initially thought," says Dr Anne Schuchat of the CDC.
At a White House briefing today, Dr Schuchat and Dr Anthony Fauci of the NIH did not mince words.
"I'm not an alarmist, and most of you who know me know that I am not, but the more we learn about the neurological aspects, the more we look around and say this is very serious."
It's serious because new research is linking Zika to more complications than previously thought -- not just microcephaly, an abnormally small brain at birth, but also miscarriage, prematurity and blindness in newborns.
Just yesterday, the disease was linked to a new neurological complication in adults.
One report from Brazil found abnormal foetal ultrasounds in 29 percent of Zika-infected women.
"We've also learned that the virus is likely to be a problem at much of the pregnancy period, not just probably the first trimester," says Dr Schuchat.
The CDC now believes aedes aegypti, the mosquito that carries the virus, is found in 30 US states, not 12 as previously estimated.
The US is no longer aggressively killing mosquitoes. Between 2004 and 2012, more than half the states reduced their mosquito trapping and testing programs.
The administration says the US$1.9 billion will be used to beef up our ability to diagnose Zika, get rid of mosquito breeding grounds, track the disease throughout the country and develop a vaccine.
"When the president asked for $1.9 billion, we needed $1.9 billion," says Dr Fauci.