As we’ve seen in so many other areas of modern medicine, the standard treatments are playing with fire, resulting in more virulent diseases and loss of ability to treat them. Malaria vaccines make the disease more virulent.
Is there any sense in vaccinating people against a disease if the vaccines will result in a more virulent form of the disease? That’s exactly the case with malaria vaccines, as demonstrated in a PLoS study.
It should come as no surprise that the malaria parasite, Plasmodium chabaudi, becomes more virulent as a result of vaccination. The bane of eradication and treatment attempts has proven to be its ability to rapidly evolve in response to such pressures. Now, a study on malaria vaccines in mice has documented the likelihood of both more virulent and infectious malarial infections as a result of attempts to immunize against it.
The study summarized:
We found that a more virulent parasite clone was less well controlled by vaccine-induced immunity than was its less virulent ancestor. We then passaged parasites through sham- or vaccinated mice to study how the parasites might evolve after multiple rounds of infection of mouse hosts. The parasite molecule targeted by the vaccine did not change during this process. Instead, the parasites became more virulent if they evolved in vaccinated hosts. Our data suggest that some vaccines can drive the evolution of more virulent parasites.
Therefore, though it’s possible that malaria might temporarily be improved by vaccination, ultimately the situation would be made worse. The only questions are how much worse and how long.