School is back in session, and for the first time, all California kindergarteners, seventh graders and new students must be vaccinated unless they have a medical exemption. A new state law bans vaccine exemptions based on personal or religious beliefs.

We've got the latest on this law and other developments in this Impatient vaccination news roundup.

California's new vaccination law

A group of parents and non-profit organizations have filed suit in an attempt to have the law nullified. They argue the law violates the state constitution's guarantee that all California children have the right to an education.

The plaintiffs filed a motion for a preliminary injunction in an attempt to block the law while their case moves forward. Last week, a judge denied their motion.

Meanwhile, a spokeswoman for the Los Angeles Unified School District says that on the first day of school, just four 7th grade students were sent home for not having their Tdap shot, which prevents tetanus, diphtheria and pertussis.

FAQ: How California's new vaccination law works

Vaccine exemptions

California is the third state in the nation – after Mississippi and West Virginia – to ban vaccine exemptions based on personal or religious beliefs.

Now, as I reported this week, the American Academy of Pediatrics is recommending that the remaining 47 states ban non-medical vaccine exemptions.

Other medical groups have already adopted similar positions, but the Academy's policy statement is noteworthy because its 64,000 members work directly with parents as they make vaccination decisions for their infants, children and teenagers.

More doctors cut ties with parents over vaccines

A survey of U.S. pediatricians, published in the journal Pediatrics, finds that between 2006 and 2013, the percentage of parents who refused to give their kids some vaccines almost doubled, from about 2.5 percent to 4.8 percent. 

This still represents a small portion of the population, but the increase in unvaccinated children could pose a threat to herd immunity in some places. Experts say for highly contagious diseases like measles and whooping cough, 95 percent of a community must be vaccinated to effectively prevent the diseases from circulating.

The pediatricians reported that the reasons parents refused some vaccines changed significantly between 2006 and 2013.

In 2006, the doctors said the top reasons were general concerns about the safety and side effects of vaccines, and more specifically, worries about vaccines causing autism and about a mercury-based preservative called thimerosal.

There have been plenty of studies debunking the theory that vaccines cause autism. There is no evidence that the low doses of thimerosal in vaccines caused harm, and the ingredient was removed from childhood vaccines in 2001.

In 2013, pediatricians said they still heard these concerns, but less frequently. The most common concern at that point, they said, was that vaccines are unnecessary. The authors of the report suggest this is because most parents of young children have little or no experience with vaccine-preventable diseases.

The survey detected another apparent trend: More pediatricians are cutting their ties with parents who refuse to give their kids at least some vaccines.

Between 2006 and 2013, the percentage of surveyed pediatricians who stopped providing care for families who refused at least some vaccines nearly doubled, from 6.1 percent to 11.7 percent.

In a policy paper published this week, the American Academy of Pediatrics says the decision to stop seeing families who refuse vaccination "is not one that should be made lightly."

Nevertheless, it says, "the individual pediatrician may consider dismissal of families who refuse vaccination as an acceptable option. In all practice settings, consistency, transparency, and openness regarding the practice’s policy on vaccines is important."

The 2006 survey analyzed responses from 629 pediatricians; the 2013 survey had 627.

Discussing vaccinations

Despite the challenges, the surveys found that almost all pediatricians try to educate parents about vaccines. In 2006 and 2013, they reported that about one-third of parents who initially refused a vaccine changed their mind after learning more.

In an effort to persuade the other two-thirds, the Academy of Pediatrics this week published a guide for pediatricians on how to have the vaccine talk.

It acknowledges that there are pitfalls; for example, a 2014 study found that for some parents who are hesitant to vaccinate, giving them more information actually increased their concerns and misperceptions about vaccines, and made them less inclined to immunize their kids.

While calling for more research on the question, the Academy recommends addressing each parent's concerns about vaccines, while also getting across the message that vaccines are safe and effective, and children are at risk if they're not vaccinated.

While these conversations can be difficult, they are important because pediatricians play a huge role in a family's decision to vaccinate, the Academy says.

"Most parents need and want education about the best way to provide care for their children, including vaccinations," the guidelines' authors write. "Dealing with vaccine hesitancy is a wonderful opportunity to continue to provide this information and education to families."

It says doctors can begin discussing vaccination as early as prenatal visits, but certainly before the family comes in for the child's first shots.