Over two months after the White House asked Congress for more than $1.8 billion to fight the Zika virus, Congress has yet to provide it. President Obama, Republicans claim, has failed to explain in sufficient detail how his administration would spend the money.

Most of the money will go to help states control the mosquito that carries the virus, expand programs to test for it and work on developing a vaccine.

The case for action now is overwhelming. Come summer, the Zika-bearing Aedes aegypti mosquito will begin to spread the disease across much of the continental U.S. Pregnant women who contract the disease are at greater risk of giving birth to children who are stillborn, have microcephaly or experience eye and brain lesions.

Among the questions Republicans say remain unanswered is what portion of the money is needed for the current fiscal year. That level of detail wasn’t necessary in 2005 when President Bush requested and received emergency funding to combat avian flu.

Republicans also argue that the federal government has enough money left over from the fight against the Ebola virus to deal with Zika. But the administration has already transferred $600 million in Ebola funds to fight Zika, and it claims that taking more could leave Americans exposed to another outbreak; there have been Ebola cases recently in Guinea and Liberia.

Finally, House Republicans say that any request for new money to combat Zika should come through the regular appropriations process, not as an emergency request. But if a disease that could endanger newborns across the southern half of the U.S. by July doesn’t qualify as an emergency, it’s hard to say what does.

This is a delay that could endanger lives. There have already been 891 cases of Zika in the U.S., including 81 pregnant women. Republicans need to move, and quickly.