Thursday, March 26, 2015

Vaccines


I saw The Vaccine War on television the other  day. You should know:

  • The development of vaccines to prevent communicable diseases has been one of the reasons that life expectancy improved so dramatically in the 20th century. Communicable diseases used to kill children by the millions in Europe and the United States, and no longer do so. The major communicable diseases that continue to kill people by the million worldwide are killers in those areas where modern public health services have not arrived, or for a few diseases -- such as malaria or HIV/AIDS -- where vaccines have not yet been developed.
  • As science progresses and more is learned about the immune system and disease agents, vaccines are getting more efficacious and safer. Research and development on vaccines for a communicable disease do not stop simply because a vaccine has been developed -- when people see how a better vaccine is possible, they try to develop it.
  • Regulatory agencies work to assure that only the most efficacious, effective and safe vaccines are in use all all times.
Think about immunizing your kids this way:

If your children's school needed some supplies that were not in the school budget, parents might well organize some activity to raise supplementary funds to buy those supplies. If you could participate but chose not to do so, you would be a freeloader. If other parents took up the slack, that supplies might still be bought. If too many parents choose to be freeloaders, the campaign will not work and all the kids will suffer.

If your church needs an expensive repair of the roof, the people who attend the church are likely to organize to raise the needed funds. If you don't participate in the effort, you are freeloading -- after all it is your church. If too many freeloaders are in the congregation, the roof doesn't get fixed, more damage occurs and the bill gets higher to do the necessary repairs.

Say you decide that traffic laws should apply to everyone else but not to you, so you drive after you have had a few drinks. exceed speed limits when you feel like it, and try to beat red lights. You may kill yourself or someone else, but more likely you will be seen driving this way by the police and you will be stopped and ticketed for breaking the law. If your conduct is flagrant enough you will be arrested as a criminal.

Communicable diseases have tipping points that determine what will happen if someone catches the disease in your community. If a high enough fraction of the people are immune, the disease may infect a a few people after it arrives in the community, but will soon die out. If too few people are immune, then an epidemic will occur and a lot of people will get sick from that disease. Sometimes conditions are just right and new vulnerable people will arrive in the community to take the place of those who have died of the disease or achieved immunity, and the disease will stay on as endemic. Public health immunization campaigns are the means by which communities assure that the vulnerability is below the tipping point.

There are some people in almost all communities who can not be immunized -- infants whose immune systems have not yet fully developed, old people whose immune systems no longer function well due to the aging process, and people with some medical conditions. We accept that some people will not allow their children to be immunized because of religious convictions in part because their numbers are small and adequate levels of immunity can still be maintained in the community 

As far as I am concerned, the people who don't have their children immunized due to sloth. or superstitious fear (that is fear of side effects not justified by medical information) are freeloaders. If there are too many such freeloaders, epidemics will take place such as the measles epidemic occurring now in the United States. Some people who get the disease will just be sick for a while, some will be permanently disabled due to the disease, and some will die of it. (I had mumps as an adult, before the MMP vaccine was developed, and I know from personal experience that that was serious enough to hospitalize me for a weak with fever and complications.)

If there continue to be too many freeloaders and periodic epidemics, stricter public health laws will be passed and enforced. Those who then fail to immunize their kids will be criminals.

I have some credentials to write the above message:
  • I wrote my Ph.D. dissertation on mathematical models in health planning;
  • I worked as a health planner in the World Health Organization, the U.S. Office of International Health, USAID, and the White House.
  • I managed research programs on the epidemiology of infectious diseases. One of them helped clarify the causes of pneumonia in children in developing nations, helping WHO to revise it standards for treatment of lower respiratory disease in children. Another showed Hepatitis C to be a far more prevalent disease in Egypt than had been believed or even thought possible, leading it to be recognized as a major public health challenge.
  • I managed research program on the application of biotechnology in bio-medical research. Eventually I directed the Office of Research of USAID, served as the U.S. Commissioner on the United Nations Commission on Science and Technology for Development, and as a consultant to the World Bank, Brazil and Mexico on programs to strengthen research management.

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