The prevalence and incidence of malaria has also been steadily decreasing worldwide, but 216 million new cases still occurred in 2010, with an estimated 655 000 deaths in that year, mainly among young children and pregnant women. It is a shocking truth that an African child dies from malaria every 60 seconds. Although there were 126 000 fewer deaths globally in 2010 than in 2009, malaria still accounted for 22% of the deaths of African children (WHO, 2011a).
In October 2011, some progress was announced from large-scale clinical trials of the RTS,S/AS01 malaria vaccine, which reduced the incidence of new infections among young African children by 50% (RTS,S Clinical Trials Partnership, 2011). This is a significant breakthrough, representing the first vaccine with established clinical effectiveness in preventing a human infectious disease caused by a parasite.
However, it is not yet known how long the protection will last, and 50% efficacy is well below the desired 95% achieved by some well-established vaccines, e.g. against measles or diphtheria. But the RTS,S/AS01 vaccine also includes surface antigens from hepatitis B viruses and gives good protection against the latter. Combined (or combination) vaccines such as this one are highly effective because they protect children against two or more diseases at the same time.
Can you identify any other combined vaccines from your own experience?
You may have suggested the MMR vaccine against measles, mumps and rubella; or the DTP vaccine against diphtheria, tetanus and pertussis (whooping cough).