Exercising parental rights is not always the same as parenting right. Case in point: Parents have the right not to vaccinate their children, but they are wrong to exercise it.

Diseases that once were all but eliminated from our shores are returning thanks in no small part to a decline in vaccination rates.

The Centers for Disease Control and Prevention reported 334 cases of measles nationwide through the end of May. Those occurred in 18 states and are the most in a year since 2000, when measles was declared eradicated in the United States. The number surely will climb in coming months.

Closer to home, whooping cough is resurgent. The California Department of Health reported 3,450 cases through June 10 and 800 in April alone, the most in a single month since a 2010 epidemic. Sonoma County is experiencing perhaps the worst outbreak with 310 confirmed cases, a rate per capita 12 times the statewide rate and more than double the next closest counties — Marin and Tehama.

The disease has hit children hardest. Ninety percent of the cases have been children younger than 18, and two infants have died in California so far.

Whooping cough is virulent. It is almost stealthy in its spread because the disease begins mildly. A runny nose and light coughing might seem no cause for alarm, but already the sick person is contagious. It might be a week or more before the coughing gets worse and the disease is properly diagnosed. By then, the sick person has exposed many more people to the virus.

Modern medicine has vaccines to prevent both measles and whooping cough. As some vaccination critics observe, those vaccines are not 100 percent effective. That is precisely why widespread vaccination is so important. The fewer people there are who are vulnerable, the more difficult it is for a disease to spread through a population. Such "herd immunity" is a cornerstone of disease prevention.

It's also true that vaccines sometimes have side effects, but they are rare, typically mild and far outweighed by the benefits.

Nevertheless, long-debunked conspiracies and myths persist. People still believe that vaccines are toxic, cause autism or are part of government mind-control efforts.

Based on such fears or out of religious conviction, too many parents opt out of vaccinating their children. As a result, those kids and others are at greater risk of illness and death. The problem is particularly acute in Sonoma County where more than 6 percent of parents request an exemption, a rate that exceeds that statewide rate. In the western stretches of the county, things are even worse. Forty percent of parents in Sebastopol Union and Twin Hills school districts request exemptions.

Before parents choose to eschew vaccines, they should think hard about whether it is worth risking their children's lives and the lives of their neighbor's children for whatever tenuous or false evidence convinced them to opt out of the 21st century. It's one thing to risk your own life based on convictions, but risking someone else's, especially a child's who has no say in the matter, is not right.