Non-specific effects of vaccines
Research done at the Bandim Health Project indicates that vaccines not only protect against the target disease, but also modulate the immune system of children in more general ways. They have so-called “non-specific effects”.
The live attenuated vaccines, measles vaccine, oral polio vaccine, smallpox vaccine and BCG vaccine, seem to confer more general protection against a broad range of pathogens. However, the non-live vaccines like diphtheria-tetanus-pertussis vaccine (DTP) have been associated with increased susceptibility to other pathogens, particularly in females.
The results indicate that the international community can save millions of children in the world’s poorest countries, if the vaccination programs are optimized to take into account both specific and non-specific effects of vaccines.
For decades our findings has been controversial, but in 2014 the World Health Organization reviewed the evidence for non-specific effects of vaccines and concluded that the findings merit further research. http://www.who.int/wer/2014/wer8921.pdf
Unfortunately, WHO has not yet started any new studies. Meanwhile, we have accumulated even more evidence for NSEs.