Potential Health Crisis Looms as Vaccine Rate Declines

Nearly five years ago California was ground zero for the largest concentrated measles outbreak in the United States since the disease was “eliminated” in 2000. Over 150 people contracted the disease over several weeks due to an extremely low vaccination rate in the State of California. During that time over a third of California counties had vaccination rates which were too low to trigger herd immunity.

Herd Immunity is the phenomenon of immunity existing amongst a whole population even if some of those in the community are unvaccinated. For a disease like measles a population must have a vaccination rate of about 95% to attain herd immunity. So, if 95% of the population in an area is vaccinated against measles, an outbreak is unlikely to occur even if the disease is introduced.

Following the critical outbreak, lawmakers jumped into action in 2015 to increase the vaccination rate by removing the controversial Personal Belief Exemption (PBE) with the passage of Senate Bill 277 in 2015. Since that law went into effect, nearly all counties boast a vaccination rate of over 90%. However, herd immunity is only effective when the vaccination rate is within the threshold among the people one encounters, and some schools and communities have dangerously low vaccine rates. School-level vaccination rates give us a good measure of the risk in communities and help public health officials determine the risk of potential contamination. While vaccination rates have been generally climbing since the passage of SB 277, according to the California Department of Public Health vaccination rates are in decline across school-aged children in the state.

One reason for this decline is the growing use of medical exemptions in place of the PBE. The number of kindergarten students with permanent medical exemptions has more than quadrupled since SB 277 passed in 2015, from 0.2 percent, or 931 total prior to the passage of SB 277 in 2015, to 0.9 percent this year, or 4,812 total medical exemptions among kindergarteners.  This year, California’s overall vaccination rates dipped below the herd immunity level to measles to 94.8%, a 0.3% decrease from the 2017-2018 school year.

Given the precarious nature of the Herd Immunity threshold a seemingly small decrease in vaccination rates could have immeasurable consequence for a school and community at large. Senator Richard Pan, a pediatrician and the author of SB 277, attributes the loss in herd immunity to the rise in medical exemptions.

Pan has taken note of the worrisome decline in vaccination rates with school children and has introduced SB 276 to require state oversight  of the medical exemption process. Less than 1 percent of children have qualifying conditions to exempt them from vaccinations, such as an allergy, but more than 100 schools throughout the state have medical exemption rates above 10% placing them outside of the immunity threshold and putting their entire communities at risk.

We are only six months into the year, and we have already seen the most recorded cases of measles since 1994. It is crucial that California once again takes leadership by ensuring the safety of all its residents. SB 276 protects those students that have a legitimate medical cause to receive a medical exemption and removes the loopholes which allow perfectly healthy children to risk the health of others.

SB 276 has already gained the support of the California Medical Association who is leading the effort and working closely with the Vaccinate California Coalition to protect all Californians from preventable diseases. It is crucial for elected officials, parents, and teachers to make a stand and join more than 75% of California residents who believe that everyone who can be vaccinated should be vaccinated  to keep our communities healthy.

Join Vaccinate California and Make a Stand for Health at vaccinatecalifornia.org.