Vaccines are powerful public health tools, but they’re only as good as their reach. And traditionally, people with means who live closer to cities access them more easily than others.

But leaders in Ghana and other countries are challenging that norm. In 2019, before the coronavirus pandemic upended the world, the Government of Ghana partnered with Zipline to deliver medical supplies, including vaccines, from local distribution centers directly to health facilities through a network of autonomous drones.

Three years later, Zipline has delivered nearly 8 million doses of routine and COVID-19 vaccines in Ghana. And early research suggests this partnership is transforming public health in ways neither Zipline nor the Government predicted.

It turns out better vaccine access creates a ripple effect. Vaccines prevent deadly diseases, but they do much more. They open the door to better health in ways that we’re only learning by changing access expectations.

Preventing missed opportunities

Imagine a woman, a farmer, who lives in the North East Region of Ghana, next to the Burkinabe border. She has two children, a newborn and a two-year-old. Her baby is sick, so she stops farming early to walk with both children several hours to the hospital in Walewale.

They wait in the heat for half the day to see the doctor. During the visit, the doctor realizes the baby hasn’t started its series of tetanus, diphtheria and pertussis vaccines.

This is a crucial moment for the family's health, and it hinges on the contents of the hospital’s refrigerator. Here, one of two things can happen.

First, the hospital has the DTaP vaccine cocktail in stock and the doctor gives the child a shot. In the second scenario, the hospital is stocked out, which means the doctor will treat the baby, then refer the mother to another clinic to start the vaccine series, or tell her to return when the hospital has the vaccine.

From a public health standpoint, the second scenario is catastrophic, according to Pedro Kremer, Head of Global Health Impact at Zipline. “In remote areas, when someone reaches a health facility there’s an opportunity to vaccinate,” he says. “If the vaccine is stocked out, that person will go home and may not make contact with the health system again for years. We call that a missed opportunity, and it is a serious public health problem.”

A missed opportunity means the baby may never receive routine vaccines, putting it at risk of contracting or spreading life-threatening diseases. Children with whooping cough, or pertussis, a bacterial infection that can cause flu-like symptoms in children and respiratory damage in babies, spread the disease to an average of 15-17 other people in unvaccinated communities.

To prevent this, the Government of Ghana partnered with Zipline to increase the reach of its vaccine distribution program. During the official program launch in 2019, Vice President Alhaji Dr. Mahamudu Bawumia declared it a “major step towards giving everyone in this country universal access to lifesaving medicines.” At that point, Zipline had already built the largest autonomous delivery network in the world, having flown more than 11,800 deliveries in Rwanda, where it launched in 2016.

Zipline had spent three years in Rwanda solving the last-mile problem for medical products, such as blood, that need to stay cold. Zipline’s two distribution centers stored refrigerated blood that had been processed by the Rwanda Biomedical Center. Doctors and nurses then ordered blood they needed for resupplies or emergencies, and a Zipline drone delivered the chilled blood within 45 minutes.

The Government of Ghana wanted to take the on-demand cold-chain model Zipline developed for blood and apply it to medical products including vaccines.

Ghana’s program launched with four Zipline distribution centers that could reach more than 2,000 hospitals and health centers across the country. By the beginning of March, 2020, the program was growing steadily. Zipline was delivering several hundred doses of routine vaccines per-month.

Then, on March 22, 2020, President Nana Akufo-Addo issued the order to close Ghanaian borders to prevent the spread of the novel coronavirus, initiating a national lockdown. Still a year out from the first COVID-19 vaccine, Ghana’s system for delivering routine, life-saving vaccines hit a wall.

Before Zipline, Ghana’s system required health workers, particularly those in the hard-to-reach communities,  to drive to a regional cold room, put vaccine doses in a cold box and transport them to a health center.

Also, at the time, 15 of Ghana’s 216 districts across the country lacked the cold-chain equipment they needed. And seven out of Ghana’s 16 regions hadn’t installed walk-in cold rooms.

This meant Zipline’s ability to ship vaccines while protecting workers’ health mattered more than ever.

Ghana’s COVID-19 response

During the pandemic, orders for Zipline vaccine deliveries skyrocketed. Demand grew from about 800 doses per-month in March, 2020 to more than 9,000 per-month in November that year. In November 2022, Zipline delivered 430,174 total vaccines from six distribution centers across the country.

“Before the pandemic, the Ghana Health Service and Zipline spent two years bringing innovative new technology to the national vaccine distribution system in Ghana,” said Dr. Anthony Nsiah-Asare, the Presidential Advisor on Health to the President of Ghana; formerly the Director General of Ghana Health Service. “Which means that when the first vaccines against COVID-19 were approved, we were ready.” 

In April 2020, global organizations UNICEF, the World Health Organization, GAVI and the Coalition for Epidemic Preparedness Innovations formed an alliance called COVAX to ensure countries all over the world could access COVID-19 vaccines.

On February 24, 2021, Ghana received its first shipment of AstraZeneca’s COVID-19 vaccines through COVAX. Less than a week later, Zipline made its first delivery of the vaccine to a health center in Ghana’s Ashanti Region.

In parallel, Zipline was working with both the UPS Foundation and Pfizer to fly COVID-19 vaccines in Ghana. In December, 2020, the United States Food and Drug Administration granted Pfizer the right to distribute its COVID-19 mRNA vaccine under emergency use authorization.

Before Zipline could transport it, Pfizer had to validate that the vaccine would stay cold and viable through the last mile of delivery. At the time, Pfizer’s mRNA product was designated an Ultra Low Temperature vaccine, meaning it needed to be frozen at -76 degrees Fahrenheit, at the warmest. Once thawed, it could be refrigerated for 30 days, and had to be used within five hours after it was brought to room temperature and prepared. 

In November, 2021 Pfizer greenlighted Zipline’s supply chain – from a facility in Belgium to storage in an ultra-cold freezer at a Zipline hub to being cold-packed in a box to, finally, that box dropping out of a drone in a parachute at a health facility in Ghana. At the time, Zipline had delivered more than 220,000 doses of COVID-19 vaccines from multiple manufacturers.

But Pfizer’s validation made it possible for an entirely new population to benefit from mRNA vaccine technology. “The freezing and refrigeration process meant that before Zipline, rural areas had almost no chance of getting these vaccines,” says Caitlin Burton, Vice President of Global Partnerships at Zipline. “But we had six distribution centers that could store these ultra-cold mRNA vaccines. We could reach millions of Ghanaians and serve even the hardest-to-reach areas.”

Today, the Government of Ghana has delivered more than 20 million doses of COVID-19 vaccines. Out of those, Zipline has flown more than 2 million via drone.

Though ten percent of the country’s vaccine deliveries, those 2 million doses have disproportionately reached vulnerable families. The majority of the vaccines Zipline delivered in Ghana went to districts with a high proportion of households led by women, rural districts, and districts where people have limited access to safe water. More than a third of vaccines were delivered within a month of expiring, and would have been destroyed in other countries without a system to distribute them before the end of their shelf life.

“The bottom line is that we are not only delivering high volumes on time, but we are also reaching those who need vaccines the most,” Kremer says. “This means we are both increasing access and reducing health inequalities.”

In areas Zipline serves, Ghana has seen vaccination rates increase by 21 percentage points, on average, across all vaccines in the routine childhood immunization schedule. This, amid what the World Health Organization calls the “largest continued backslide in vaccinations in three decades.”

Also, Ghanaian health facilities served only by Zipline cut the duration of stockouts by 60%, on average, compared to those that received supplies from other sources, according to research conducted by global analytics firm IDinsight and funded by the Bill & Melinda Gates Foundation. Zipline-served facilities also had a 42% reduction in missed opportunities for vaccination compared to other facilities.

In other words, Zipline has helped the Ghanaian government turbocharge its vaccine distribution system. By improving access and reducing missed opportuniites, Zipline vaccine deliveries in Ghana have potentially saved the lives of more than 700 children, according to a new study led by Kremer, who will publish this and other results in a peer-reviewed journal this year.

What’s more, collaborative research from Kremer’s team and health officials at Ghana's Western North Region Health Directorate indicates that the health benefits of Zipline’s vaccination program extended beyond the preventive power of vaccines.

Opening the door to better public health

Zipline’s GH4 hub in Sefwi Wiawso sits between the city of Kumasi and Ghana’s western border with Côte d'Ivoire, one of the country’s most difficult areas to reach with essential medical supplies. While looking at the data around vaccination coverage for GH4, Kremer found something interesting.

“We found that children treated at facilities served by our GH4 hub had fewer episodes of diarrhea compared to control groups.” Kremer said, “But the reduction was independent from the increase in vaccination coverage for the disease.”

Kremer says one potential explanation is that once people know a facility is served by Zipline, they trust that the treatments they need will be there, so they’re more likely to go at all. “Maybe they go for a vaccination or a specific condition, and a provider is able to talk about safe water, disease prevention, and other health issues – then you start seeing better outcomes,” Kremer says. “If the supply chain is working, it triggers more trust in the system. More trust translates into more consultations and better health results.” 

In the coming year, Zipline intends to scale its success in Ghana by bringing vaccination programs to new countries. Since launching in September, 2022, Zipline has delivered more than 300,000 doses of vaccines from its hub in Kaduna State in Nigeria, an area with one of the country’s highest rates of zero-dose children.

“We’ve seen evidence that Zipline can help us address one of the most significant public health challenges on the planet: Reaching children who have never received life-saving vaccines,” says Moz Siddiqui, Head of Private Sector Partnerships & Innovation at GAVI. “We are helping people access known treatments for deadly diseases. In many cases, we know the science – now we’re working to solve the access problem.” 

Vaccination is medically simple – it takes seconds. But the system behind getting a high-quality vaccine to a facility and into the arm of a person can be complex.

Zipline wants to change that. In the next several years, working with governments and international partners, Zipline’s delivery platform could make it easy for more health centers across the world to stock vaccines.

That means when mothers walk miles with their children and doctors see an opportunity to prevent life-threatening diseases, they can. It means, as Zipline vaccination programs expand in Ghana, Nigeria, and other countries, these crucial, snapshot public health interactions move from catastrophic to preventive. It means that healthcare workers will have more of the resources they need to prevent disease and earn the trust of their patients. Most importantly, it means fewer people will get sick and die because of where they live and what happens to be in the refrigerator at the hospital when they need care.

Vaccines are powerful tools for public health. And now, Zipline and partners are creating a supply chain that changes who can get them and when, allowing government and public health leaders to fully tap into their power.