The new type of corona virus still poses many puzzles. For example, the question of why some people still remains unanswered – even if they are young and healthy – get very seriously ill with Covid-19 while others do not even feel symptoms.
In addition, the virus appears to be less dangerous for children. They are significantly less likely to get seriously ill with Covid-19 than adults and also have the lowest risk of dying of all age groups. So far, however, there have been quite contradicting studies about what role they play in the infection process.
The children of the parents suffering from Covid-19 were repeatedly tested negative for the virus
A case from Australia shows again that the immune system of children could react differently to the virus than in adults. In a family from Melbourne, both parents developed Covid-19 with clear symptoms after attending a wedding without their children.
This happened at the beginning of the pandemic in Australia and the family was selected for a Murdoch Children’s Research Institute (MCRI) case study, during which they were tested every two to three days. The study was recently published in the open access journal “Nature Communications”.
The couple’s three children, all of primary school age, were repeatedly tested negative for the coronavirus – although they were in close contact with their parents and one of them even slept with them in bed. In addition, they developed no or only mild symptoms. Nevertheless, the researchers later found antibodies against the Sars-Cov-2 virus in the blood of all family members.
The immune system of children can apparently prevent the virus from multiplying
“The youngest child who showed no symptoms at all had the strongest antibody response,” said Melanie Neeland, immunologist at MCRI and head of the laboratory-based aspect of the study. “Despite the active immune cell response in all children, the cytokine levels, molecular messenger substances in the blood that can trigger an inflammatory reaction, remained low. This was consistent with her mild or no symptoms. “
The family recovered from Covid-19 without needing medical attention. However, it is not yet clear whether and for how long she is actually immune to the coronavirus. According to Nigel Crawford, pediatrician and vaccine expert at MCRI, the case study shows that the immune system of children is apparently able to stop the virus from multiplying in the body despite chronic exposure.
A recent study from the USA came to a similar conclusion. According to this, children fight the virus very early – before it has the opportunity to multiply in the body. “Studying immune responses to Sars-Cov-2 in all age groups is key to understanding susceptibility to the disease, differences in severity, and vaccine candidates,” says Crawford.