[ad_1]
From the earliest days of the coronavirus pandemic, scientists observed that children appeared to be less susceptible to developing COVID-19, although the exact reasons remain unclear.
Now, an unusual case in Australia can provide a unique insight into the mystery, thanks to the experience of a young Melbourne family.
In this family of five, the two parents fell ill with COVID-19 after attending an interstate marriage without their children. However, the symptoms did not manifest until a few days after returning from the trip.
However, unbeknownst to them, they had brought SARS-CoV-2 into their home and exposed their children there.
The family with MCRI researchers. (MCRI)
Once both parents developed symptoms – including cough, congested nose, fever, and headache – the entire family was tested for the virus. Parental tests were positive. The children’s tests came back negative.
“It was astounding because they had spent a week and a half with us while we were COVID positive,” her mother, Leila Sawenko, told ABC News.
However, the truly surprising part was yet to come.
Healthcare professionals asked the family to retest, but once again the tests on the children came back negative for SARS-CoV-2, even though two of the boys in the family (aged 9 to 7) had mild symptoms .
The youngest daughter, a 5-year-old girl, remained asymptomatic throughout the episode, although she often slept in the same bed as her parents during the illness (physical removal precautions not feasible at home during quarantine).
Intrigued by the negative results of the children as they lived so close to the infected parents, the researchers asked the family to take part in a study, analyzing blood, saliva, stool and urine samples, and taking nasal and throat swabs every two for three days.
Oddly, despite repeated polymerase chain reaction (PCR) tests showing that the children were consistently negative on SARS-CoV-2 PCR, the researchers found SARS-CoV-2 specific antibodies in the saliva of all members of the family and in detailed serological tests.
In other words, the children never tested positive for the virus, but a certain level of exposure to the virus still triggered an immune response within them, apparently able to counteract the infection.
“The youngest child, who showed no symptoms, had the strongest antibody response,” says immunologist Melanie Neeland of the Murdoch Children’s Research Institute (MCRI).
“Despite the active immune cell response in all children, the levels of cytokines, molecular messengers in the blood that can trigger an inflammatory reaction, remained low. This was consistent with their mild or absent symptoms.”
Fortunately, all family members who fell ill were cured and did not need medical attention.
The mechanisms underlying children’s immune responses are still not fully understood, but understanding how and why their immune responses were activated (in the absence of confirmed cases of the virus) could shed more light on children’s susceptibility to COVID-19. roughly.
“This study is kind of our first step to really look into children’s immune systems and to see which components might respond to the virus,” said study first author, University of Melbourne pediatrician Shidan Tosif. The age.
“The fact that these children were able to stop the virus and not even show a positive test result suggests that they have a certain level of their immune system that is able to respond and effectively deal with the virus, without ever becoming much. sick people”.
Indeed, the researchers think that the children were indeed infected with the virus, but their immune systems were somehow able to activate an anti-virus response that was very effective in limiting the replication of the virus, unlike their parents.
That immune response was so effective, it could have brought the viral load so low, that it went under the sensitivity of the PCR test, which is another issue that requires further scrutiny, the team thinks.
“The discrepancy between virologic PCR results and clinical serological tests, despite an evident immune response, highlights the limits to the sensitivity of nasopharyngeal PCR and current diagnostic serology in children,” the researchers write.
For Leila Sawenko and her family, they are simply happy to have all the swabs and exams behind them, and excited to contribute in their own way to our better understanding of this pervasive virus and what it arouses within us.
“It was a ‘wow’ moment that despite the fact that the children tested negative, they had developed antibodies,” Sawenko said. ABC News.
“You could only see the look on the doctors’ faces. They were completely amazed and really excited to think there was this discovery.”
The results are reported in Nature Communications.
.
[ad_2]
Source link
