The Obama administration, though, is sticking with its $1.9 billion request, some of which would cover the shift.
Only infected newborn mice developed severe symptoms, similar to humans.
The World Health Organization (WHO) on Apr 1 shared more information about Martinique's first probable Zika-related microcephaly case, which documents Zika virus infection in the mother and the fetus.
Officials warn that lack of funds could hinder countermeasure development, battle against mosquitoes.
Structure details may yield clues on how Zika damages cells and offer an inside track to drug, vaccine, and test developers.
The area of the US that could be home to the culprit mosquitoes and thus affected by Zika is wider than previously thought.
About 31% thought the virus spreads through sneezes, and 42% didn't know about sexual transmission.
The genetically engineered mice have already yielded some pathogenesis clues.
The updates include guidance on postponing pregnancy, more finely tuned tips to prevent sexual spread, and a push for reliable contraception access in Puerto Rico.
Researchers say Zika might have been brought to the Americas from French Polynesia during a soccer tournament.
