Vaccine Bill Brieger | 18 Jan 2011 09:42 am
15 Months, 46 percent – prospects for malaria vaccine
Researchers on the new RTS,S/AS01E malaria vaccine have extended the follow-up period on the children who had received the vaccine in Kenya and Tanzania and the vaccine which had offered 53% protection against malaria at 8 months, continued to be protective, though at a slightly reduced rate of 46% at 15 months.
People who bet may not like those odds, but the key to understanding this vaccine, which is likely to be the first into the public health system when final trials are over, is the nature of the actual effect. While the vaccine does not prevent the occurrence of malaria in most recipients over the long haul, it does prevent life threatening severe malaria including cerebral malaria and severe anemia – factors that contribute to malaria mortality.
The public health challenge going forward is three-fold (at least). The first challenge will be affective delivery of the vaccine though national immunization programs, which have had trouble keeping up with coverage of the routine immunizations like DPT and measles.
The second is convincing the public that a vaccine that does not completely prevent malaria in all children is worth their effort to get imminuzed. This is compounded by local perceptions that any fever might be malaria, and as we know there are many viral and bacterial causes of fever co-existing in the same environment and children as malaria. The vaccine will prevent malaria to an extent, but not preent fevers. This chalenges out ability to communicate.
The third challenge is how one should combine vaccination with prompt and appropriate case management (diagnosis, treatment and counseling) for those who do get malaria after the full regimen of the new vaccine. This tests the oft stated premis that a vaccine is not a magic bullet, but part of a package of control interventions. One also hopes that people trust the vaccine to the extent that they abandon their insecticide treated bednets.
The battle for a malaria vaccine just begins when the research trials are finished. It is at this point where the human element, represented by health systems managers, community leaders and health consumers, need to be considered. If this were a new soft drink or cell phone product facing the effectiveness and efficacy challenges described above, one could forgive investors from being wary. In this case we cannot afford to be overly cautious investors when children’s lives are at stake.