PROVO, UTAH - OCTOBER 27: A nurse administers a shot of the H1N1 vaccine at the Utah County Health Department October 27, 2009 in Provo, Utah. After health department got a shipment of 4000 vaccines overnight, a large line formed with a wait of four to five hours. (Photo by George Frey/Getty Images)
More and more parents are choosing not to vaccinate their children. In fact, the number of parents opting out has nearly quadrupled in the last 20 years.
A report by the San Diego Watchdog Institute found parents are mainly choosing not to immunize their kids against the measles, mumps, and whooping cough.
Their decision takes on new scrutiny as California battles its worst whooping cough epidemic in 50 years.
Health officials are urging parents to get their children caught up on vaccines before students head back to school this year as the whooping cough epidemic approaches its peak in California.
State health officials say more than 3,000 cases of the illness have been confirmed as of Aug. 17 in California, a 7-fold increase from the number of cases reported in the same period last year.
Whooping cough, or pertussis, is a highly contagious respiratory illness. Eight infants in California have died from the illness this year, including a two-month old boy from San Diego County.
State department of public health spokesman Ken August says children who aren't vaccinated may be required to stay home under the authority of county health departments, in the event of an outbreak.