In humans, the most rapid period of brain development begins in the third trimester and continues over the first two years of extra uterine life. (By then, brain development is 80 percent complete.) Until randomized controlled trials demonstrate the safety of giving vaccines during this time of life, it would be prudent not to give any vaccinations to children until they are 2-years-old.
From a risk-benefit perspective, there is growing evidence that the risk of neurologic and autoimmune diseases from vaccinations outweigh the benefits of avoiding the childhood infections that they prevent. An exception is hepatitis B vaccine for infants whose mothers test positive for this disease.
A user-friendly vaccination schedule prohibits any vaccines that contain thimerosal, which is 50 percent mercury. Flu vaccines contain thimerosal, which is reason enough to avoid them.
One should also avoid vaccines that contain live viruses. This includes the combined measles, mumps, and rubella (MMR) vaccine; chickenpox (varicella) vaccine; and the live-virus polio (Sabin) vaccine. This stricture would not apply to the smallpox vaccine (also a live-virus one), if a terrorist-instigated outbreak of smallpox should occur.
Finally, a user-friendly vaccination schedule requires that vaccinations, after the age of two, be given no more than once every six months, one at a time, in order to allow the immune system sufficient time to recover and stabilize between shots.
Which vaccines should be put on this schedule (among those that do not contain live viruses or thimerosal) is not entirely clear. The top four would be:
Pertussis (acelluar -- aP -- not whole cell) vaccine.
Diphtheria (D) vaccine.
Tetanus (T) vaccine (the first three on this list are to be given separately, not together, as is usually the case).
The Salk polio vaccine, with an inactivated (dead) virus, one that is cultured in human cells, not monkey kidney cells.
Perhaps, it should only contain these four vaccines. A good case can be made for avoiding the three other newer vaccines on the CDC's schedule: The hepatitis B, pneumococcal conjugate (PCV7) and Hemophilus influenzae type b (Hib) vaccines. [Donald W. Miller, Jr., MD]