In recent weeks, a record number of whooping cough cases have been reported in Croatia and Serbia. In the latter country, four children have already died, while 70 cases have been recorded, half of whom are hospitalized, one in critical condition. Serbian experts stated in early January that the situation was concerning because the disease had nearly disappeared, a vaccine is available, yet parents are increasingly refusing vaccination.

The National Public Health Center has reassured the Hungarian public with a statement claiming there is no need to fear an epidemic domestically due to the vaccination rate being above 98 percent. The immediate experience during the COVID-19 pandemic highlighted the importance of establishing so-called herd immunity, but also taught us that pathogens find their way through any gap in our defenses.

The bacterium causing whooping cough is still present in Hungary.

What does whooping cough cause, and how can it spread "unnoticed" among us? What is the significance of the vaccine, and is there vaccine resistance in our country? How can we protect infants under two months who are not yet covered by the vaccine? We asked Dr. Zoltán Nyul, university lecturer and head physician of the Infectious Diseases Department at the PTE Clinical Center Children’s Clinic.

TORTUROUS BOUTS LIKE A DONKEY’S BRAY

The disease caused by the bacterium Bordetella pertussis is transmitted from person to person through droplets and is among the most contagious pathogens. The bacterium settles and multiplies on the respiratory mucosa, with inflammation and toxins produced by it causing symptoms. The classical clinical picture for children consists of three stages.

After a one-to-two-week incubation period, general respiratory symptoms such as coughing, runny nose, and malaise appear in the first 10-14 days, much like a mild cold, but usually without fever. The symptoms do not subside as they would with banal respiratory virus infections; instead, they gradually intensify, transitioning into the second stage characterized by severe coughing fits.

"Torturous, stubborn fits of dry cough occur in extended bouts. Coughing sequences often end in vomiting, the child can barely breathe, and hypoxia can develop. The coughing fit is typically followed by a deep "pulling" inhalation, which sounds like a donkey braying, hence the name of the disease" says Dr. Zoltán Nyul to 24.hu.

At the peak of infection, bouts can occur 10-30 times a day and this stage can last up to six weeks. The third phase is about relief; the fits gradually subside, but full recovery is still weeks away.

FOR ADULTS "NOTHING SERIOUS," BUT POTENTIALLY DEADLY FOR INFANTS

Good news: in Hungary, thanks to vaccines, the aforementioned frightening whooping cough symptoms in children have practically vanished. The infection has shifted to adults, where the vaccine's effect fades, but symptoms are often atypical and minimal: prolonged, stubborn dry cough that most people don’t even seek medical care for. Why? This might be due to partial immunity or because adult airways are proportionally wider, so respiratory constriction is less significant than in children.

Thus, the bacterium is continuously circulating among adults, with many transient respiratory infections being misattributed to Bordetella pertussis despite their mild or non-characteristic progression.

The greatest risk is to newborns and young infants, who have no immunity, since the maternal protection against pertussis is insufficient, and they don't receive their first vaccination until two months old followed by three more until two years of age, then another one between ages 3 and 7. Stubborn cough may also occur in them, but respiratory pauses and apneas are more common, which can lead to hypoxic neurological damage, seizures, and pneumonia. Up to one percent of cases can be fatal.

To protect the youngest, the practice of vaccinating mothers during pregnancy is becoming increasingly common in the West, and this is supported by Dr. Zoltán Nyul. The antibodies produced in the mother’s body reach the fetus, who is thus born with some protection and is not completely vulnerable to the pathogen in the first two months. The local guideline recommends vaccination to those in the environment of the unborn child.

PROTECTION COMES THROUGH VACCINATION, NOT JUST FOR THE BABY

Widespread vaccination, through the creation of herd immunity, is one of the biggest advantages in epidemiology. A more detailed explanation of its "operation" can be found here with the help of Professor András Falus, an immunologist. Its essence is to protect the community from an epidemic, but not necessarily the individual from infection and its consequences. However, even with high vaccination rates in the Western world, the number of whooping cough cases is on the rise. Vaccine resistance, becoming more perceptible, is one, though not the only, reason for this trend:

"Where vaccination discipline has relaxed, the disease has re-emerged more frequently, affecting more children," emphasizes Dr. Nyul.

Vaccine resistance has been perceptible in Hungary for a long time. However, while many countries recommend vaccination, it is mandatory in Hungary. This means that regardless of the parents' opinions, the prescribed vaccinations including the one for whooping cough must be administered to the child. Failure to comply can result in public health and misdemeanor fines, and the absence of vaccination is generally classified as endangering the child by the authorities. In the most extreme cases, the child could even be removed from the family. The legal background of the issue can be read in a short and logically structured summary by TASZ here.

The whooping cough vaccine may have mild, transient side effects, but there is no doubt about the maximum safety of the vaccines used. The problem is that the protection is not for life; to avoid the disease, a booster is needed every ten years in adulthood, especially since over the age of 65, the infection becomes riskier again. Not to mention that even relatives carrying the bacterium without symptoms can inadvertently infect the newborns.