Germany recorded its highest number of whooping cough cases since 2013, with infants under one year being the most affected group. Experts anticipate similar case numbers for 2025. Vaccination of expectant mothers against the pertussis bacterium, Bordetella pertussis, offers protection to infants in their first months of life.
Researchers from Charité – Universitätsmedizin Berlin and Radboud University have shown that maternal antibodies are present in both the blood and nasal mucosa of newborns. The international study was published in The Lancet Microbe.
Whooping cough can be fatal for newborns, who receive their first vaccine dose at two months. Protective antibodies develop after the second dose at around four months. To bridge this vulnerable period, pregnant women in Germany and most European countries are advised to get vaccinated, passing protective antibodies to their unborn child via the placenta. This method provides effective indirect immunization from birth.
A research team, led by Prof. Beate Kampmann, confirmed the presence of maternal antibodies not only in the blood but also in the nasal mucosa of newborns. The nasal mucosa is the primary entry point for the pathogen. Prof. Kampmann stated that the detection of antibodies in the nasal mucosa was a surprising finding that underscores the effectiveness of indirect vaccination.
The international study involved 343 pregnant women in The Gambia, West Africa, who received either a whooping cough or tetanus vaccine. Maternal antibodies against whooping cough were detected in both the blood and nasal mucosa of infants whose mothers had received the whooping cough vaccination.
The researchers also examined blood and nasal secretions from approximately 160 newborns before and after their routine pertussis vaccinations, which utilized different vaccine types.
The study indicated that babies who received a whole-cell pertussis vaccine at 8, 12, and 16 weeks of age developed a stronger immune response on average than those who received an acellular vaccine. Whole-cell vaccines contain the complete, inactivated pertussis bacterium, while acellular vaccines contain only purified components. Acellular vaccines generally cause fewer side effects but typically offer shorter-lasting protection.
Prof. Kampmann suggested that the whole-cell pertussis vaccine might provide longer-lasting protection. The research team highlighted the need for further investigation into the clinical implications and vaccination strategies.
Acellular vaccines have been used in Europe since 2005, while many low- and middle-income countries use whole-cell vaccines. Prof. Kampmann advised that countries currently using whole-cell vaccines for children should continue to do so. She emphasized that vaccinating pregnant women with the acellular vaccine remains crucial, regardless of the vaccine type given to children, as both types prevent whooping cough in newborns in over 90 percent of cases.
In Germany, the Standing Committee on Vaccination (STIKO) has recommended whooping cough vaccination for pregnant women since 2020, but the vaccination rate is approximately 50 percent, below the target. Prof. Kampmann noted that these results demonstrate that vaccination during pregnancy provides double protection for infants during their most vulnerable period, which is a strong argument for utilizing vaccination offerings given the rising case numbers.
Whooping cough remains a deadly disease globally, causing 200,000 to 300,000 deaths annually, primarily among young children in countries where effective vaccines are not always available. The research team plans further studies to improve existing pertussis vaccines and test new ones.