Friday, March 21, 2008

Vaccination, herd immunity, and selfishness

Two main papers ran articles on vaccination today. Let's take a look at them. Remember I'm speaking for myself here as our disclaimer notes.

"Vaccine Failure Is Setback in AIDS Fight: Test Subjects May Have Been Put at Extra Risk Of Contracting HIV" by David Brown, Washington Post Staff Writer, Friday, March 21, 2008; Page A01 talks about the bitter conclusion.

"This is on the same level of catastrophe as the Challenger disaster" that destroyed a NASA space shuttle, said Robert Gallo, co-discoverer of the human immunodeficiency virus (HIV), which causes AIDS, and head of the Institute for Human Virology in Baltimore.

This seems to put off a prevention of AIDS for the foreseeable future, meaning that millions especially in Third World countries will continue to die:

"None of the products currently in the pipeline has any reasonable chance of being effective in field trials," Ronald C. Desrosiers, a molecular geneticist at Harvard University, declared last month at an AIDS conference in Boston. "We simply do not know at the present time how to design a vaccine that will be effective against HIV."

Meanwhile, theoretically well-educated people refuse to vaccinate their children in the US - read "Public Health Risk Seen as Parents Reject Vaccines," By JENNIFER STEINHAUER, New York Times March 21, 2008.

Let's pull out some quotes from this article:

SAN DIEGO — In a highly unusual outbreak of measles here last month, 12 children fell ill; nine of them had not been inoculated against the virus because their parents objected, and the other three were too young to receive vaccines.

Now, let's see what the Centers for Disease Control says about measles - "How serious is the disease? Measles itself is unpleasant, but the complications are dangerous. Six to 20 percent of the people who get the disease will get an ear infection, diarrhea, or even pneumonia. One out of 1000 people with measles will develop inflammation of the brain, and about one out of 1000 will die."

Hmmm. Let's see what a parent in the article has to say:

“I refuse to sacrifice my children for the greater good,” said Sybil Carlson, whose 6-year-old son goes to school with several of the children hit by the measles outbreak here. The boy is immunized against some diseases but not measles, Ms. Carlson said, while his 3-year-old brother has had just one shot, protecting him against meningitis. “When I began to read about vaccines and how they work,” she said, “I saw medical studies, not given to use by the mainstream media, connecting them with neurological disorders, asthma and immunology.”

Nice. So she's willing to risk her children to a 1 in 1000 risk of death because of something she read that the mainstream media (and the FDA and CDC) refuse to believe. So far, nobody has been able to prove that vaccination increases the risk of autism, which is what most people who fear vaccination seem to be most concerned about.

“The very success of immunizations has turned out to be an Achilles’ heel,” said Dr. Mark Sawyer, a pediatrician and infectious disease specialist at Rady Children’s Hospital in San Diego. “Most of these parents have never seen measles, and don’t realize it could be a bad disease so they turn their concerns to unfounded risks. They do not perceive risk of the disease but perceive risk of the vaccine.”

So what happens to herd immunity, or the phenomena in which even if an individual's vaccination doesn't take, one's protected by the fact that a virus can't infect anyone around him?

There is substantial evidence that communities with pools of unvaccinated clusters risk infecting a broad community that includes people who have been inoculated. For instance, in a 2006 mumps outbreak in Iowa that infected 219 people, the majority of those sickened had been vaccinated. In a 2005 measles outbreak in Indiana, there were 34 cases, including six people who had been vaccinated. Here in California, six pertussis outbreaks infected 24 people in 2007; only 2 of 24 were documented as having been appropriately immunized. A surveillance program in the mid ’90s in Canada of infants and preschoolers found that cases of Hib fell to between 8 and 10 cases a year from 550 a year after a vaccine program was begun, and roughly half of those cases were among children whose vaccine failed.

The current John Adams miniseries on HBO shows the lengths that Abigail Adams was willing to go to inoculate her children. Here's some pictures of smallpox, which was the first disease prevented by vaccination to show why she, and George Washington who vaccinated the Continental Army, went to such lengths.

Woman with smallpox with vaccinated infant (the opposite of the situation in the NY Times article in which the parent is protected, but the child is not).

No comments: