History buffs and infectious-disease experts have already drawn links between the rubella outbreak in the 1960s and the current spread of Zika.
But drugmakers today face greater regulatory hurdles, and the federal government has yet to dedicate funding to address the Zika epidemic. That means a vaccine and successful methods to stop transmission of the virus may be a long time coming.
Nearly 75 years ago, an Australian ophthalmologist noticed he was treating cataracts in a significant number of newborns whose mothers were infected with rubella early in their pregnancies.
It was the first time researchers understood the long-term impact of the disease, which, for adults, was virally spread and caused relatively mild symptoms—mostly a rash. Doctors in other countries began to link rubella-infected mothers with babies born with deafness, heart problems, developmental disabilities, liver damage and bone and joint deformities. And then, between 1964 and 1965, more than 12.5 million people in the U.S. became infected. About 20,000 children were born with congenital rubella syndrome.
That was the last time the nation experienced a scare with the long-term health and financial impact now posed to populations vulnerable to the Zika virus, which until recently was believed to be spread only by mosquitoes.
According to the Centers for Disease Control and Prevention, the one-year rubella epidemic cost the country an estimated $840 million, which is equivalent to about $6.5 billion today. But Congress broke for the summer this month without debating a $1.1 billion bill to fight the Zika virus.
The World Bank has estimated the disease's worldwide economic impact at $3.5 billion in 2016, mostly because of people avoiding travel to areas where the virus is being actively transmitted. It does not attempt to include the costs of children growing up with microcephaly or the cost of developing a vaccine.
Regulatory and safety requirements will likely add years and many millions of dollars to the effort. In the 1960s, consent to participate in drug clinical trials was given on a relatively small, simple form and testing could be done on a larger population. Today, the Food and Drug Administration's vaccine guidance alone is 13 pages long. The process of developing, testing and winning approval for a vaccine often takes more than 10 years.
A study in the American Journal of Public Health estimated a benefit-to-cost ratio of nearly 8-to-1 for the rubella vaccine. The analysis factored in the costs of public and private vaccination programs and medical attention for adverse reactions versus the savings generated by eliminating the long-term consequences of congenital rubella syndrome.
Without a Zika vaccine, federal and local public health officials are spending their own funds to educate communities about the risk of Zika even as they themselves learn more about how mosquitoes and people spread the disease.
Officials in Utah are dealing with the recent discovery that an elderly man infected with Zika may have transmitted it to his caregiver. The elderly patient has since died.
Dr. Sonja Rasmussen, director of the CDC's Division of Public Health Information Dissemination and incoming president of the Teratology Society, said one of the scariest aspects of Zika virus is how much is still unknown.
Researchers are unsure whether a woman must be symptomatic to pass the virus along to her fetus or whether it matters at what stage of the pregnancy the woman is infected.
Dr. Sarah Obican, assistant professor of maternal fetal medicine at the University of South Florida, said pregnant women typically get what is called a dating ultrasound in their first trimester. The doctor can do a rudimentary anatomy check but will not be able to tell much of anything about brain structure. At 18 to 20 weeks, a doctor can use an ultrasound to look at a baby's growth by comparing the size of the femur and abdomen to the brain circumference.
For a woman with a positive test for Zika, Obican would suggest an ultrasound every three to four weeks beginning two weeks after exposure to examine the brain structure. That information can only tell so much, however. “I have no idea about function,” she said. “I can only say if there is abnormality in the structure there is a higher chance.”
Doctors studying Zika and preparing to work with patients say they don't expect significant difficulty getting blood tests and additional ultrasounds covered by health plans because they are part of necessary prenatal care.
The price of an ultrasound depends on the location of the test, type of equipment used and other factors, but it can be relatively expensive. “Insurance can give you a hard time, but good documentation helps,” Obican said.
One thing that's certain is that children with microcephaly will need a full range of physical, occupational and speech therapy throughout their lives. Some will likely require help with feeding and other activities of daily life.
There isn't enough information to estimate life expectancy, she said, but children with fetal brain disruption at the level of severe microcephaly can need several million dollars worth of medical care into adulthood. The emotional costs for a family, she added, are also staggering.
Dr. Edward R.B. McCabe, chief medical officer for the March of Dimes, said there is a range of treatments depending on the severity of microcephaly, but many babies will need developmental services in the first six months of life. “These intensive early intervention services would include physical, occupational, speech and hearing therapy,” he said. “And today, both developmental and behavioral pediatricians are in short supply, so this will not be easy on any family.”
There is not enough information to know whether there would be a large difference in payment through Medicaid versus private insurance, he said. “The biggest unknown is the lack of experience with this level of severe microcephaly.”