Tahiri and her baby daughter have joined a courtyard full of women sheltering their babies from the midday sun at a health centre in Ankareira, near Madagascar's southern tip.
"I had a two-year-old and a three-year-old child and they both got sick and then died, one after the other," she said.
Tahiri, who grows rice and manioc in one of the poorest, most drought-affected regions of the country, does not know what illnesses killed her first two children, but she has brought her daughter to the clinic to be vaccinated because she wants to give her the best chance "to have good health".
Madagascar has reduced its under-five child mortality rate by more than 60 percent over the last decade. Part of that success has been down to increased vaccine coverage, with the World Health Organization and UN Children’s Fund (UNICEF) estimating that 78 percent of the country's children were immunized in 2009, compared to 57 percent in 2000.
That increase was made possible partly as a result of funding from the Global Alliance of Vaccines and Immunization (GAVI), a public-private partnership launched in 2000 to improve access to vaccines in developing countries such as Madagascar, where it has contributed US$56.5 million.
GAVI says its support to NGO and public health programmes which deliver vaccines has saved five million children from premature death over the last decade, and that it can save four million more over the next four years by doubling the number it helps immunize to half a billion and introducing two new vaccines.
To do this GAVI estimates it will need $6.8 billion, but so far donors have only promised to fund about half that amount. GAVI hopes to raise the remaining $3.7 billion at a pledging conference in London on 13 June.
"For a long time vaccines were unavailable in the developing world, in countries such as Madagascar, either because the appropriate vaccines for these kinds of countries and conditions didn't exist, or because they were too expensive," said GAVI spokesman Ed Harris on a recent visit to Madagascar.
Harris said that while countries like Madagascar clearly needed development in many sectors, vaccines were one of the most cost-effective interventions.
His comments are supported by findings from two studies conducted at the Johns Hopkins Bloomberg School of Public Health in Baltimore published in the June issue of Health Affairs. Both studies project that boosting efforts to develop and deliver vaccines could not only save the lives of 6.4 million children but save $6.2 billion in treatment costs, and achieve $145 billion in long-term economic gains by avoiding the lost productivity resulting from premature death.
UNICEF Madagascar representative Bruno Maes said now more than ever, support from organizations like GAVI was vital as Madagascar continues to feel the effects of a protracted political and economic crisis which started in 2008 and has caused poverty levels to increase and government spending on health to drop from $8 to $2 per person.
"This is a drastic reduction for essential services for children, and we are very concerned about their vulnerability," said Maes.
According to UNICEF, which was one of GAVI's founding partners, 38,000 Malagasy children under the age of five still die every year and under-funding of the health sector has started to reverse some of the country's immunization gains. Coverage for measles vaccination, for example, has fallen from 2007 levels of 81 percent to 64 percent in 2010.
Marie-Josephine Hantomalala, head of the clinic in Ankareira which does vaccinations twice a week, is worried she will have to turn away the crowd of women and their children waiting outside, many of whom left their homes at dawn to reach the clinic by foot.
"The fridge for the vaccines has broken down and the temperature has dropped to 19 degrees," she said, adding that a vaccines expert in the nearest city, over two hours drive away, could not respond to her call for assistance because he lacked petrol.
In addition to providing affordable vaccines to Madagascar, GAVI has spent almost $10 million on strengthening the health system to deliver them in remote rural clinics that often lack the kerosene to run fridges needed for vaccine storage.
District Doctor Andriatsararanto Rabetsivahiny, who works in the Amboasary-Sud region of southeastern Madagascar, said in an area where over 130,000 people live more than 5km from the nearest health centre, initiatives to increase vaccine coverage had greatly helped reduce child mortality.
While malaria and diarrhoea were still major causes of deaths in children, deaths from measles were much less common than previously. He added that the biggest killer was malnutrition as undernourished children were vulnerable to attack from a number of diseases and often too weak to survive them.
He said in an area with little cultivatable land and high unemployment, "in times of difficulty people live off tamarind mixed with ash and water - morning, noon and night, just to survive".
Two new vaccines in pipeline
Manjarasoa, 18, has walked for an hour with her one-year-old baby to reach the Ankareira clinic.
"It's been five days since he's had diarrhoea. I've been feeding him herbal tea but it just hasn't stopped," she said.
Since 2001, GAVI has helped immunize children against tetanus, diphtheria, hepatitus B and pertussis (whooping cough) using the tetravalent vaccine. The introduction of the pentavalent vaccine in 2008 added protection against Haemophilus influenzae type B (Hib).
Now GAVI, along with UNICEF and other partners, wants to help developing countries introduce two new vaccines. The first would protect children from pneumococcal disease, the leading cause of pneumonia, and the second would provide protection from rotavirus, the most common cause of severe diarrhoea. Pneumonia and diarrhoea are the two leading killers of children under the age of five, causing nearly 40 percent of all childhood deaths.
"Children in rich countries don't die from diarrhoea," pointed out Shanta Bloemen from UNICEF South Africa, while children in the poorest most remote areas who could not easily be reached with treatment were vulnerable.
"If every child is vaccinated you're giving them the primary foundation to survive the first few years of life when they are most vulnerable to disease and have weak immune systems, and in Madagascar... almost half the children are malnourished so they are vulnerable," she told IRIN.
Madagascar has been earmarked among the developing countries which could benefit from GAVI funding for pneumococcal and rotavirus vaccines, but the availability of financing will depend largely on the success of the pledging conference and on the price of the vaccines coming down. In response to a recent tender by UNICEF, which procures the majority of vaccines funded by GAVI, Merck & Co and GlaxoSmithKline have significantly reduced the price of their rotavirus vaccines.
With a child dying every 20 seconds from a vaccine-preventable disease, Harris said: "At stake on 13 June are potentially millions of lives."