Facts About Childhood Vaccines
What is the difference between DTP and DTaP?
DTP included Diptheria,Tetanus and whole cell Pertussis. DTaP includes Diptheria, Tetanus and purified Pertussis antigen/acellular pertussis antigen. The whole cell vaccine is made of just what it says: the whole cell. There were hundreds, or thousands of proteins in the vaccine: most had nothing to do with creating a protective immune response, but the still did cause the body to mount a response, a response that caused a lot of pain, some high fevers, and some more serious but rare side effects such as episodes of low blood pressure and prolonged crying in infants. The newer, acellular pertussis vaccine contains only the antigens needed to produce protective antibodies. It protects against pertussis without so many side effects.
Why has the number of shots risen so dramatically?
First of all, new vaccines have been added: the HIB requires three to four doses, hepatitis B vaccine requires three doses (two for teens) and the varicella one (two for teens).
Second, we have for safety reasons changed from the oral polio, which was a live, attenuated vaccine, to the inactivated/injected polio vaccine. With there being NO cases of wild polio in the US since 1979, but about ten cases per year of vaccine-associate paralytic polio (VAPP) among the elderly and immunocompromised, the CDC decided it would be safer for the population at large to switch over to the inactivated vaccine. This may change if we ever see wild polio here, and that could theoretically happen: polio remains a problem in third world countries, though the World Health Organizations efforts are decreasing the incidence.
Finally, for a while we were able to use a vaccine that combines the DTP with the HIB. However, when we switched over to the DTaP, studies showed that the combined vaccine offered poor protection from HIB for young infants. So, we have to give these separately now. The good news is that scientists are working on formulations that will combine vaccines safely and effectively, to decrease the number of shots. Also, vaccine "guns", Star Trek-like devises that use compressed air to painlessly shoot vaccine through the skin without a needle, skin patches, nasal sprays, and food-borne vaccines are other technologies that are being investigated.
No one gets these diseases anymore so why does my child need to be vaccinated?
It's true we don't often see these diseases in this country anymore, but they are still a concern. We don't see them because we enjoy a phenomenon called "herd immunity." So many people have protective antibody that the germs do not have susceptible hosts in which to grow and spread. However, we know, from recent experience (measles in the US in the early 90s, pertussis in England in the 80s) that when vaccine levels fall these diseases reemerge. Sometimes they are carried by protected hosts, but cause illness in the unvaccinated. Sometimes they are introduced from other countries. It remains important to get children immunized both from a personal and a public health point of view.