Several years ago, at the height of anti-vaccination hysteria - which was sparked by a now thoroughly debunked study purporting to link childhood vaccines to autism -New Jersey and other states made it easier for parents to opt out of vaccination requirements for schoolchildren.

New Jersey had always allowed exemptions for parents whose legitimate religious beliefs compelled them to refuse such medical intervention. But the law, here and elsewhere, was liberalized to allow an exemption pretty much to anyone who asked for one.

As a result, while there were 452 religious exemptions granted in New Jersey in 2005-06, there were almost 4,000 exemptions granted in 2009-10.

Another result of the liberalization of these laws: Whooping cough cases are now at the highest level in five years. Nearly 18,000 cases had been reported to the federal Centers for Disease Control and Prevention in the first six months of 2012 - twice as many as at the same time last year.

Folks, whooping cough - or pertussis - kills. Vaccinations work by creating so-called "herd immunity." That requires the absolute maximum number of people to be vaccinated. As vaccination rates fall, more and more people in the "herd" are walking around with the bacterium, and infants too young to be vaccinated, people whose immune systems are compromised due to illness and others are at greater risk of acquiring the disease.

Vaccines don't just protect your children - they protect all of us.

A bill in the Legislature would, once again, toughen up the requirements for a religious exemption. It's a simple, necessary measure - and the misguided anti-vaccination movement must not be allowed to kill it.

Religious exemptions would still be available, but parents would have to document and explain their bona fide religious belief and make it clear that their objection is not merely a political or philosophical belief or related to concerns about vaccine safety.

Yes, vaccines - like all medical procedures, like all of life - do have risks. But the likelihood of an adverse reaction is extremely rare. And the benefits - to all of us - of herd immunity are extremely clear.

The anti-vaccination movement is the result of two worrisome trends in our society.

One is an almost medieval mistrust of science. The 1996 British study purporting to link vaccines to autism wasn't just debunked - it was debunked as a fraud, complete with doctored data.

The second trend is the refusal or inability to acknowledge community - that we are in fact a herd that to a large degree depends on its individual members acting for the benefit of all.

Childhood vaccinations are safe and effective, and they save lives. Exemptions should not be easy to get. Pass the bill.