Gov. Jerry Brown has signed a bill to further strengthen California's mandatory vaccine laws by requiring that people who work or volunteer at day care centers be vaccinated against certain diseases.



The Democratic governor announced Sunday that he approved a bill requiring day care centers and homes to maintain immunization records proving their workers and volunteers have been vaccinated for the flu, pertussis and the measles.



Lawmakers approved SB792 by Democratic Sen. Tony Mendoza of Artesia this fall after an earlier debate over vaccinations in schools roiled the Capitol for months.



In June Brown signed a hotly contested bill imposing one of the strictest school vaccination laws in the country, following an outbreak of measles at Disneyland late last year.