2. You are analyzing data from a case-control study about risk factors for pertussis (also known as whooping cough). The investigators recruited 40 infants from hospitals in Northern California who presented with whooping cough symptoms and matched each to a neighborhood control. They examined whether or not mothers had received the Tdap vaccine during pregnancy as a way to curb pertussis infection in their infants. They found that 31 mothers received the Tdap vaccine during pregnancy, of whom 3 had infants who developed pertussis, and there was only 1 case-control pair where both mothers received the Tdap vaccine during pregnancy.

A. Calculate the unmatched odds ratio

B. Complete the table below and calculate the matched odds ratio Controls Received Did not receive Total Tdap Tdap Received Cases Tdap Did not receive Tdap Total