The California Department of Public Health has reported that whooping cough incidents in the state in June is four times higher than last year and declared an epidemic.
Family doctors blamed the confirmed 910 cases to inadequate insurance reimbursement for vaccinations for adults and gaps in vaccination for schoolchildren.
The California Academy of Family Physicians (CAFP) also blamed doctors' practice of not storing vaccines and instead referring patients to community clinics, grocery and drugstores for their vaccines.
The CAFP is now throwing its support to a California legislation requiring insurers to reimburse doctors for the full cost of buying and administering vaccines.
The bill also prohibits dollar limits on childhood and adolescent immunizations.