California will open 2020 with a new law that's expected to make it more difficult for parents to circumvent the state's vaccination requirements for children entering school.

The move is expected to shore up vaccination rates within a state that has been among the most effective over the past decade at bolstering immunizations among kindergartners.

SB276 will take effect Jan. 1 and is designed to make it more difficult for parents to obtain illegitimate medical exemptions that allow children to avoid vaccinations. Medical exemptions are allowed for children with compromised immune systems, and who would not be able to safely receive certain vaccines.

But California doctors in recent years have been able to grant exemptions without broader approval from the state's health department. And allegations have surfaced that some doctors have granted the exemptions illegitimately, in some cases allegedly selling exemptions to parents who didn't want their children to be immunized.

Under the new law, California's Department of Public Health will make the final call on which children are granted exemptions, closing a vaccination loophole and upsetting an anti-vaxxer community that believes immunizations may be detrimental to children's long-term health, despite scientific evidence to the contrary.

"It is my hope that parents whose vulnerable children could die from vaccine-preventable diseases will be reassured that we are protecting those communities that have been left vulnerable because a few unscrupulous doctors are undermining community immunity by selling inappropriate medical exemptions," Dr. Richard Pan, a pediatrician and state senator representing California's Sacramento area, said in a statement after Gov. Gavin Newsom signed the bill into law in September.

Despite the immunization concern, California's kindergartners boast one of the highest vaccination rates in the country. An estimated 96.9% of California kindergartners in 2018 had been vaccinated for measles, mumps and rubella, according to an analysis of Centers for Disease Control and Prevention data conducted by Health Testing Centers . The Golden State had the eighth-highest vaccination rate in the country for those diseases and the ninth-highest rate of polio immunization at 96.8%.

Mississippi, Maryland and West Virginia lead the nation in the percentage of their kindergartners with measles, mumps and rubella vaccinations. More than 98% of kindergartners in all three states have been immunized. The three states also lead in polio vaccinations.

Top 10 States for Measles, Mumps and Rubella Vaccination Rates



On the low end are Colorado, Kansas and Idaho, the three states in which fewer than 90% of kindergarteners have been vaccinated for measles, mumps and rubella. Colorado, at 88.7%, also has the lowest rate of polio vaccinations.

The Health Testing Centers report sets a national vaccination rate goal of 95% for all of the diseases it examines, which 23 states had met in 2018. Wyoming didn't report vaccination data to the CDC that year. Another 26 states fell short of that benchmark.