First, Ewan picks up the vaccines from a vaccine storage centre.
The vaccine journey Ewan’s taking is called a “cold chain”, because the vaccines have to be kept cold at all times. If they freeze or get too warm, they’ll be useless.
There are cold chains in virtually every city, town and village in the world. This is just one of them.
In a nomadic camp in Patna, Nargis and her little brother Irfan are getting a polio vaccination.
“India hasn’t had a new case of polio in over a year,” Ewan says.
It’s an amazing achievement – only two years ago, India had more polio cases than any other country.
Local health workers and volunteers are vital to the cold chain.
Amit in the yellow shirt is a vaccinator at Patna train station. He finds children who aren’t protected and gives them a vaccine on the spot.
Amit had polio when he was young, so it means a lot to him to protect children from the disease.
It takes Ewan 12 hours to reach the village of Terasi by boat and motorbike.
Two-year-old Phultan is getting his polio vaccination. It’s an oral treatment rather than an injection.
Phultan’s mom heard about the importance of vaccinations from a UNICEF-trained community worker who talks to families in the village.
Cold chains can be fragile. Terasi is often flooded, which makes it difficult for local health workers to reach children.
When that happens, UNICEF sends immunization teams in boats to make sure every child gets their polio vaccine.
Vaccines need to be kept cold all the time – between 2˚C and 8˚C. That’s hard work in hot countries like India!
It costs just $143 to buy a cold-box vaccine carrier like the blue one in the photo. This simple box can get vaccines to the children who need them, whatever the weather.
Every day two million people cross the border between India and Nepal, so the risk of infection is high.
Here in the border-town of Forbesganj up to 800 children are immunised every day.
That’s over 250,000 a year.
To get to the Himalayan village of Luma, Ewan’s plane has to land on one of the world’s most dangerous runways.
“Only a handful of pilots in the country are qualified to land here,” Ewan says. “A few days earlier, a passenger plane blew out its tires and crashed.”
Strong winds and snow mean flights carrying vital vaccines are often cancelled. UNICEF and its partners make sure there is always at least nine weeks’ worth of supplies in local stores in case the runways are closed. That way, no child has to miss out.
Safely off the plane, Ewan chats with Shersingh, a UNICEF health worker. Random fact: ‘Shersingh’ is Nepalese for tiger lion.
Karna, who is carrying the vaccines, works for a local hospital. He’s lived in this area all his life and does regular cold chain vaccine runs.
Together they head into the valley – there are no roads for hundreds of miles.
After the two-day trek, Ewan arrives at the tiny mountainside village of Luma.
Four-month-old Bura is getting her measles vaccine from the local vaccinator.
“We’re very poor and it’s hard to get by,” says Bura’s mother Rahindra. “But I’m very pleased that my baby is getting her measles vaccine as I know it will keep her safe.”
It’s a big day for 11-month-old Nirmala and her mom.
It’s taken Ewan and the health workers four days to get the vaccine to her.
It’s all over in a second but will last a lifetime.
In the first part of his BBC documentary, Ewan McGregor: Cold Chain Mission, Ewan traveled with UNICEF to India and the remote mountains of Nepal.
UNICEF is the world's largest distributor of vaccines to the developing world, supplying vaccines for more than half the world's children in over 190 countries.