The widespread introduction of vaccines has prevented more than a million children dying from two of the deadliest childhood diseases, new research has found.
The study, by researchers at Johns Hopkins University in the United States, found that 1.45 million fewer children under five died from infections caused by the pneumococcus and Haemophilus influenzae type b (Hib) bacteria, largely thanks to the introduction of vaccines in low income countries.
The pneumococcus bacteria alone is responsible for 11 per cent of early childhood deaths and is, according to the World Health Organization (WHO), the leading vaccine-preventable cause of death among infants and children under five.
The research, which focused on the countries where deaths from these two diseases are most prevalent, found that falls in mortality were greater after vaccines were introduced. Deaths from pneumococcus fell by 51 per cent, while deaths from Hib were down 90 per cent.
The researchers say that the findings provide valuable evidence to encourage countries to introduce childhood vaccination programmes.
“The introduction of these vaccines in countries with the highest burdens is contributing to a reduction of overall childhood mortality,” said Dr Brian Wahl, an assistant scientist at Johns Hopkins University and the study’s lead author.
“Reducing deaths from pneumonia and meningitis is a key way to reduce overall childhood mortality,” he said.
The recent introduction of the vaccines – particularly in India – has great potential to reduce the overall tally of childhood deaths, he added.
Each year, 5.6 million children around the world die before reaching their fifth birthday. In 2015, Hib infections killed 29,500 children, while pneumococcus killed around 294,000. Even when not fatal, septicaemia and meningitis – two of the diseases caused by the bacteria – can lead to permanent brain damage and disability.
Vaccinations against Hib have been available to young children in the UK since 1992, while the pneumonia vaccine has been widely available since 2006, leading to a fall in the number of cases of meningitis, pneumonia and septicaemia.
Although the researchers said that the sharp falls in the number of childhood deaths from Hib and pneumococcus in developing countries were also explained by better hygiene and access to healthcare, they found that vaccines helped speed up the decline in deaths.
“The estimated average annual decline in child deaths from pneumococcus jumped from 3 per cent during 2000 and 2010, to 8 per cent after 2010 when many high-burden countries began widespread immunisations with the vaccine,” he said.
Pneumoniaremains the single largest infectious cause of death in under-five children worldwide. Around a third of those deaths are caused by the pneumococcus bacteria with half of pneumococcal disease deaths occurring in four countries – India, Nigeria, Democratic Republic of the Congo and Pakistan – that have not either not introduced or only just introduced the vaccines.
“With pneumonia, efforts now are still focused on introducing and scaling up the vaccine in countries that have not introduced it or are in the initial stages to get the overall burden of diseases down,” said Dr Wahl. “With Hib, there’s a real opportunity to get the numbers really low.”