The long line of women, with babies strapped to their backs and young children by their sides, suddenly rush forward when the motorbike pulls up in the grounds of Garzon village school, about an hour and a half's drive from the Liberian capital of Monrovia.
Many of the women have been waiting for hours in the humid morning heat for the arrival of the bike's passenger, community immuniser Jemama Weegie.
Dressed in a medical uniform of dark green smock and black trousers, and carrying a small cold box of vaccines, Weegie is here to immunise pregnant women, new mothers and babies under the age of one as part of an outreach programme that covers around 27 villages in the area each month.
With two helpers, Weegie sets up a table, takes out a pile of child medical records and paper from her bag and arranges an orderly queue. Over the next two hours she will screen and counsel more than 70 women and children and offer free vaccination against diseases including measles, yellow fever and polio. She also administers pentavalent, a vaccine that immunises against five diseases (diphtheria, tetanus, pertussis, hepatitis B and Hib).
"We do outreach to hard to reach areas where people don't have transportation to get to the clinic," says Weegie. "Before we do the outreach work, we go to the village and talk to women about the importance of immunisation - why it is good to do - and we tell them when to bring their children. I'm very happy we do this because it means children will not get sick and diseases will stop destroying lives."
The outreach programme is organised by Kingsville clinic, where Weegie has worked since 1998. The clinic is a government-owned facility that is managed by Save the Children and provides free medical care to a community of more than 20,000.
Garzon is only 5km from the clinic, but it's a journey over potholed roads and can take up to an hour when the rains come.
Sianeh Roberts, 19, has just received a tetanus injection, and her tearful seven-month-old son, Prince, has been given polio and pentavalent shots. Roberts left her home at 7am to make sure she was seen. She says she worries that her son will get sick as she has no money to pay for drugs. While government health centres offer free healthcare and medicine, people with little money will often buy drugs from a local private source because it's cheaper than paying for transport to a clinic.
"I will tell other people to come for vaccines. The vaccines will make my son well, so I know it's important," says Roberts.
Outreach programmes are providing a lifeline in a country where, according to government figures, 67,830 children died last year before reaching their fifth birthday. The under-five population is around 595,000.
But Liberia has made significant progress in cutting its under-five mortality rate. According to Unicef, in 1990 there were 247 deaths per 1,000 live births; by 2009, the number had been slashed to 112. Increasing immunisation is a major part of the government's strategy to reduce this figure still further. It recently published its five-year plan to increase routine immunisation coverage from around 69% to 90% by 2015. It is also hoping to receive funding from the Global Alliance for Vaccines and Immunisation (Gavi) to roll out the pneumococcal vaccine next year.
Next week London will host a Gavi conference on vaccination funding.