[News Terms] Essential for Newborn Families... 'Baekilhae' Vaccination

As the COVID-19 pandemic subsides and the flu season ends, whooping cough is now spreading mainly among infants and elementary school students. Reports from overseas indicate that whooping cough, which was prevalent during the Victorian era in the 19th century, is sweeping across Europe again after hundreds of years.

Whooping cough is a respiratory disease caused by infection and transmission of the Bordetella pertussis bacterium, a gram-negative bacterium. It is characterized by severe paroxysmal coughing lasting more than 14 days, accompanied by a "whooping" sound at the end of the cough, vomiting, conjunctivitis, and other symptoms. In Korea, it is called "Baekilhae" because it involves coughing for a hundred days.

Whooping cough is highly contagious and is classified as a second-class legally designated respiratory infectious disease. It is particularly threatening to infants; when newborns are infected, even with intensive treatment, the fatality rate reaches 4%, and most whooping cough-related deaths occur in infants under 3 months old. Additionally, infants under 6 months may suffer serious complications such as pneumonia, otitis media, pneumothorax, seizures, and encephalopathy. In the past, mortality rates were higher in younger age groups, with the highest mortality in those under 1 year old, but the incidence has significantly decreased since vaccination became mandatory.

According to the Korea Disease Control and Prevention Agency, whooping cough is prevented by the Tdap combination vaccine, which protects against diphtheria, tetanus, and pertussis. The vaccine is administered in three doses at 2, 4, and 6 months of age, with a fourth dose given between 15 and 18 months. The fifth dose is given at ages 4 to 6, and the sixth dose at ages 11 to 12, with booster shots recommended every 10 years thereafter.

The recent resurgence of whooping cough is believed to be due to the relaxation of strengthened quarantine measures during the COVID-19 pandemic and reinfections occurring through asymptomatic hidden carriers among adults with weakened immunity. A report on the surge of whooping cough published in the British Medical Journal (BMJ) cited a decline in vaccination rates caused by the spread of negative perceptions about vaccines, especially among COVID-19 vaccine opponents. In fact, in the UK, the vaccination rate for whooping cough among pregnant women dropped sharply from over 70% in September 2017 to 58% in September 2023.

Experts emphasize that not only newborns but also infants and elementary school students attending daycare or kindergarten, who live in group settings, are at high risk of contracting or transmitting whooping cough if incompletely vaccinated. Therefore, it is crucial to receive vaccines on schedule. The Korean Society of Obstetrics and Gynecology recommends Tdap vaccination for pregnant women between 27 and 36 weeks of pregnancy. Additionally, parents, adolescents, and grandparents in households with newborns who have not been vaccinated with Tdap should receive the vaccine at least two weeks before close contact with the baby.