Is there an upside to vaccine side effects?    

            American children receive more than 40 immunizations by the time they reach first grade. Boosters are due during teen years and physicians recommend vaccines against pneumonia and shingles when we reach Medicare age. The value of vaccines is accepted by all but a few who feel that the dangers of vaccines justify their avoidance. It’s true that some vaccines have severe, sometimes fatal side effects. For the families in which such tragedies occur there is small consolation in knowing that the benefits of widespread immunization far outweigh the hazards. A half-century ago a pediatrician might see dozens of children every month with measles, mumps or rubella (German measles). Today’s pediatricians may practice for years without seeing a single child with one of these diseases.

            In countries such as the United Kingdom when the fear of whooping cough (pertussis) vaccine sharply reduced immunization levels there were hundreds of deaths due to the natural disease, far more than suffered vaccine complications. In every country in which polio immunization levels are high the incidence of paralytic polio is zero. Today in Pakistan the Taliban have forced a halt in polio vaccination and more than 40 children there contracted the disease in 2013. That number is probably an underestimate.

            The most common side effects of most vaccines are pain at the injection site and low-grade fever. Seizures (convulsions) were fairly common in children who received older versions of pertussis vaccine but the newer versions rarely cause this complication.

            A child will sometimes develop a mild rash following measles vaccination but the dreaded complications of natural measles are nonexistent in children who have received the vaccine.

            If a child has a high fever or some other complication, even a seizure, following immunization it could indicate an unusual susceptibility to the natural disease. If that child were to be exposed to the wild virus he or she might have been the one child in a thousand who developed encephalitis during a pre-vaccine-era measles outbreak or who died of other measles complications. In other words, a greater than normal reaction to the vaccine virus might indicate that the natural virus would have caused a serious, perhaps fatal, infection.

            When a vaccine causes a mild illness it’s not be something to worry about. Instead it may indicate greater susceptibility to the real thing and parents should be relieved that their child is now protected.