PD Editorial: A needless risk of public health

California reported 258 cases of pertussis in the first six months of 2009. The disease, commonly called whooping cough, was nearly eradicated.

Fast forward five years, and California health officials have declared a pertussis epidemic.

Almost 8,000 cases were reported through Sept. 2, including three fatalities and 267 cases serious enough to require hospitalization. All of the fatalities and 169 of the most serious cases involved infants less than four months old.

These are preventable diseases - and needless deaths.

So is measles, another disease that’s making an unwelcome comeback.

Unlike the Ebola virus sweeping West Africa, there are proven vaccines for pertussis and measles. They are safe and effective, inexpensive and easily accessible.

Yet a growing number of parents, many of them concentrated in the wealthiest and best educated communities in the state, are putting their children, their children’s classmates and countless other people at risk by eschewing vaccinations.

To get around vaccination requirements for public and private schools, these parents file a form called a “personal belief exemption.” Created to accommodate religious beliefs of a relatively small number of people, they’ve instead created a chasm in the public’s defense against infectious diseases.

In some west Sonoma County schools, health officials have reported, as many as 40 percent of the students have such exemptions on file. Recent news reports have found even higher concentrations at schools on Los Angeles’ affluent westside.

“In some schools, up to 60 to 70 percent of parents have filed these PBEs, indicating a vaccination rate as low as that of Chad or South Sudan,” according to a report in the Atlantic. “Unlike in Santa Monica, however, parents in South Sudan have trouble getting their children vaccinated because of an ongoing civil war.”

Statewide, the percentage of kindergartens where at least 8 percent of children are entering school without full immunizations has more than doubled since 2008. The rate is increasing faster at private schools than public schools, the Los Angeles Times reported.

The issues here are junk science and baseless suspicion.

Peer-reviewed research by scientists in the United States and abroad affirms the safety of vaccines for measles, polio, pertussis, mumps and other diseases. Arguments to the contrary are no more credible than claims that climate change is a hoax. Moreover, there’s empirical evidence that vaccinations work. These resurgent diseases were all but eradicated before a now thoroughly discredited article appeared in the medical journal Lancet more than a decade ago. The author lost his medical license, the results were retracted.

Yet people still fear or say they want to choose.

This wouldn’t much matter if only those who aren’t vaccinated were at risk of contracting pertussis and other communicable diseases.

But that’s not the case.

Widespread vaccination is central to a public health strategy called herd immunity. If a large enough portion of a community is immunized, it creates a barrier, blocking the spread of a disease. Even those who aren’t inoculated are protected to a large degree if immunization is wide-spread. That isn’t license to say no thanks; it’s the protection necessary for infants who are too young to be immunized - such as the infants sickened or killed by pertussis this year - or those who for medical reasons cannot be inoculated.

One of the great medical breakthroughs of the 20th century was vaccination. Millions of lives have been saved, but that triumph of public health is at risk of slipping away, and that would be inexcusable.