Tom Frieden is director of the Centers for Disease Control and Prevention. Edward McCabe is chief medical officer of the March of Dimes.

Over the past year, we’ve seen the life-altering effects of the Zika virus on newborns. Images of babies with abnormally small heads and other birth defects have been shown in newspapers and on TV broadcasts. These images often show the hands of their parents feeding, bathing and comforting them, or the hands of doctors or nurses caring for them. These hands represent the intensive, potentially lifelong support that many of these children will need. For families, this will demand love, patience and hope. For doctors and nurses, it will demand learning new ways to treat patients. For the government, it will require funding, research and commitment.

Nearly a year ago, the Centers for Disease Control and Prevention (CDC) activated its Emergency Operations Center, and scientists began working around the clock to try to understand and control Zika’s spread. The March of Dimes began educating women and families on Zika prevention and supporting health professionals as they prepared to care for babies affected by the virus. Hundreds of CDC staff members continue to work intently to protect pregnant women and learn more about how to control Zika. We increasingly understand that this emergency has implications that affect families and communities as well as our health, social services and educational systems.

As we approach the one-year mark of this emergency response, we reflect on the lessons we’ve learned. We’ve learned that if a pregnant woman is infected with Zika in any trimester, the virus can cause devastating birth defects and other developmental concerns not apparent at birth. We’ve learned that Zika can be transmitted sexually in addition to being carried by mosquitoes.

We began mosquito-control efforts in affected areas and educated people about mosquito-bite prevention. We advised pregnant women to not travel to areas with Zika, and for men returning from those areas to use condoms with their pregnant partners to prevent sexual transmission.

The fight against Zika stands out as one of the most intense experiences of our careers. But when we think of this past year, beyond the tremendous research, education and treatment challenges, we remember those affected by this unprecedented virus.

We have met families in the United States and abroad caring for babies affected by Zika. We’ve heard questions that we are not yet able to answer: Will my baby survive? Will my son learn to feed himself? Will my daughter learn to walk or talk?

We’ve also met with parents whose babies were born without signs of the most severe effects of Zika — but who fear they might develop problems in years to come. We don’t have answers for them yet, either.

And what about women who become pregnant and test positive for Zika in the future? What’s their risk of having a baby with congenital Zika syndrome? Preliminary data from the U.S. Zika Pregnancy Registry suggest that about 1 in 10 babies infected in the first trimester of pregnancy will develop serious brain damage. These data provide helpful clues, but many questions remain.

The first wave of the outbreak has slowed, but we must not let our guard down, particularly in the Southern United States , where the mosquitoes that spread Zika can be found. We must continue to support research to develop a safe and effective vaccine for those at risk of Zika infection. We need better diagnostic tests for Zika and more effective methods to control the mosquitoes that spread the virus. And we must prepare for the affected infants who will be born before a vaccine is available. We need dedicated and qualified hands to care for these infants.

There are things parents and caregivers can do while we wait for answers. It is important for parents to monitor their child’s growth and development and to voice concerns so that their child’s doctors can evaluate them for developmental delays. Regularly attending follow-up appointments in the first years of life will help doctors track the growth and development of babies exposed to Zika and intervene if needed. For parents of babies affected by Zika, we want to help them feel prepared for the future and supported with the right medical care and other services.

The Zika virus affects all Americans. In addition to the overwhelming emotional toll on families, the CDC estimates that lifetime medical and educational costs for each baby born with microcephaly could be more than $10 million.

Affected children will need protection, support and attention for decades to come. As we look to the future, we hope to see images showing the hands of community members helping to control mosquitoes, the hands of health professionals protecting the next generation from Zika with new vaccines and the hands of caregivers helping affected children to reach their full potential.