In the past 25 years, the world has made enormous strides in keeping young children healthier for longer. Thanks to a combination of improved healthcare, better education and economic development, the global mortality rate for children under five has declined by more than half, dropping from 12.7 million deaths in 1990 to almost six million in 2015.

But hidden in those figures is a group of children who are still losing their lives at an unacceptable rate. Approximately 45 percent of all under-five deaths occur during a child’s first 28 days of life, what’s called the neonatal period. According to the World Health Organization (WHO), the proportion of children dying in the neonatal period has increased in all regions over the last 25 years.

Health experts used to consider neonatal deaths an intractable problem. But there is hope today that the answer to reducing the rate of neonatal mortality could be found in a relatively simple solution: chlorhexidine, an everyday antiseptic used in mouthwash.

The reduction in overall under-five child mortality worldwide is due to various factors, including the spread of immunization, better nutrition and treatment of childhood illnesses, increased access to family planning and overall improvements to the economies of lower-income countries. But, experts say, the particular threats that children face in the days immediately after they are born are not getting enough attention.

“Children who die in their first month of life account for a major portion of under-five deaths,” says Nosa Orobaton, former chief of party of USAID’s Targeted States High Impact Project in Nigeria. “We must step up our game.”

One of the main causes of neonatal death is sepsis or infection. “When the umbilical cord is cut, the clock starts to tick,” Orobaton says.

Experts believe many of these infections are caused by people applying traditional remedies like ash, oil, butter, spice pastes or mud to freshly cut cord stumps. It’s a common practice in many cultures in the belief that these substances help to dry or lubricate the umbilical cord, or serve medicinal or protective purposes. Studies show that replacing those natural treatments with an application of chlorhexidine – which requires no special equipment or training – could decrease neonatal mortality by 23 percent.

Chlorhexidine is a broad-spectrum antiseptic antibacterial agent used in different formulations to clean the skin after an injury or in preparation for an injection or surgery. It’s also an ingredient in pharmaceutical products and mouthwash. The use of chlorhexidine for cord care has a track record of being safe and stable. Developed countries had been using the agent for umbilical cord care for 40 years until, in 1999, the WHO advised it was unnecessary in sterile settings and called for more research into its suitability in high-risk settings. It is extremely low cost – about U.S.$0.23 per dose – and easy to use. Perhaps most importantly, it doesn’t provoke cultural objections in countries where it has been introduced.

Those reasons make chlorhexidine especially suitable for developing countries, where it can be used by both health facilities and women who deliver in their homes, without skilled attendants, in even the most remote areas. The WHO added four-percent chlorhexidine (7.1 percent chlorhexidine digluconate) for cord care to its Model Lists of Essential Drugs in 2013, having earlier listed the agent in other concentrations for different uses.

Nepal has been leading the world in recognizing the benefits of chlorhexidine for umbilical cord care, says Leela Khanal, project director at JSI Research & Training Institute, a key partner in Nepal’s national roll-out program. A revolutionary 2006 Nepal study published in the Lancet found that application of chlorhexidine to cord stumps reduced neonatal mortality by 34 percent in babies who received the treatment within their first 24 hours. In 2011, the country expanded nationwide a program to include application of chlorhexidine to the umbilical cord immediately after birth into essential newborn care.

“Nepal is a learning hub, and representatives from more than 20 countries have visited to observe and learn from Nepal’s program,” said Khanal. The country is also the first to produce chlorhexidine in gel form, which is easier to apply to cord stumps than liquid, and has sold the gel to seven other countries so far.

The key to Nepal’s success with chlorhexidine is its government’s commitment to allocating resources for the health rights of the entire population, according to Penny Dawson, senior technical advisor at the JSI Research & Training Institute. “Nepal’s government led the efforts to ensure nationwide coverage of chlorhexidine,” she says. The government’s move in 2007 to establish a technical working group that included private sector representatives to guide the program to produce a gel version of chlorhexidine, along with a social commitment from Lomus Pharmaceuticals – which produces the chlorhexidine gel for very little profit – helped ensure the success of those efforts.

While Nepal is charging ahead, the rest of the world is just starting to catch up. It was only in 2014 that the WHO issued a new recommendation for umbilical cord care, calling for daily chlorhexidine application to the umbilical cord stump during the first week of life for newborns who are delivered at home in settings with high neonatal mortality (30 or more neonatal deaths per 1,000 live births). Now a handful of other countries, including Nigeria, Madagascar, Pakistan and Ethiopia, also actively distribute the gel and have it on their national lists of essential drugs.

While the widespread use of chlorhexidine could stop a significant portion of neonatal deaths, it isn’t a magic bullet. Ultimately, say experts, ending all preventable newborn deaths would require essential care being available to women and babies everywhere during childbirth and the period immediately afterward. A recent report by Save the Children noted that skilled care during childbirth could reduce newborn deaths by 43 percent.

In the meantime, with such an inexpensive and accessible way to help reduce the rate of neonatal mortality, newborns have a better chance of finally joining the rest of world’s children in living longer, healthier lives. In a 2013 Global Health article, Nepali government officials and NGO experts asked: “Does chlorhexidine deserve the billing of game changer?” They then answered their own question: “Preventing one in six neonatal deaths would be huge. ‘Game changer’ seems, to us, a pretty good fit.”