In a five month long time period between September 2013 and January 2014, nearly 26 preschoolers, two staff members and 11 family members of the staff or students at the facility in Leon County suffered from whooping cough.

A new report has suggested that a whooping cough, or pertussis, outbreak at a Florida preschool, wherein almost all the students had received vaccination against the disease, has triggered concern regarding the effectiveness of the vaccine.

The Centers for Disease Control and Prevention (CDC) released a research article on Wednesday shedding light on the potential waning strength of the present vaccination recommended to prevent pertussis, or whooping cough.

As per a report published by the journal Emerging Infectious Diseases on January 13, five of 117 students, who went to the preschool, had not got all of the shots need by their age.

The two classrooms that reported the highest attack rate (AR) due to the disease included 3-year-olds. One of them had an AR of about 50% and also an infectious staff member.

The report mentioned that sustained pertussis transmission in a vaccinated group, including 1- to 5-year-old children, has been reported in the US.

Five epidemiologists, staff members at the Florida Department of Health in Tallahassee, said that this age group is usually thought to be safe from whooping cough through vaccination.

The first case of outbreak got confirmation in December 2013, when a 1-month-old infant tested positive for whopping cough. Soon, it was found that the older sibling and the mother of the infant also had same symptoms with the illness before the baby was diagnosed.

The report noted that as a whole no increased incidence of disease has been seen in the county.