The largest study conducted so far on children with the new coronavirus provides very important evidence that males and infants may face an increased risk of infection or serious illness.
The CDC, U.S. Centers for Disease Control and Prevention, they published a very important study yesterday. The study looked at over 2.500 coronavirus cases among US children under the age of 18 between February 12 and April 2. It is the largest research sample of children with coronavirus to date.
Overall, the data suggest that children are less likely to develop coronavirus symptoms than adults.
Of all cases reported in the United States, only 1,7% were children, although they represent 22% of the population.
Among the children for whom complete information was available, 73% developed fever, cough or shortness of breath. A lower figure than 93% of adults reported in the same period of time, between 18 and 64 years.
The findings support previous research conducted by the Chinese CDC, according to which most infected children had mild or asymptomatic cases.
Serious cases even among children
Although in a very large minority, some children develop serious consequences from the coronavirus. 147 of the patients in the new CDC study were hospitalized, with 5 sent to ICU and 3 deaths.
The newborns observed had a much higher hospitalization rate than any other infant age group. Of the 95 infants in the study, 62% were hospitalized. The estimated percentage for children aged 1 to 17 was at most 14%.
"We know that children's immune responses evolve over time", Dr. Yvonne Maldonado, chair of the infectious disease committee of the American Academy of Pediatrics. "The first year of life, babies don't have the same robust immune response as older babies and adults."
Some biological factors could make males more sensitive to COVID-19
Increasing research has suggested that men die of COVID-19 at higher rates than women.
WHO reported that as of March 20, men represented approximately 70% of coronavirus deaths in Western Europe.
Data from five countries with some of the world's largest outbreaks suggest men they are 50% more likely to die of women after a coronavirus diagnosis, according to a March 20 analysis by CNN and the Global Health 50/50 academic research group.
Coronavirus in Italy
An analysis of more than 25.000 coronavirus cases from the Istituto Superiore di Sanità found that male coronavirus patients in Italy had a mortality of 8%, compared to 5% of Italian women. The same analysis found that men represented the majority of coronavirus cases in Italy: approximately 58%.
Some experts have pointed out that men have a higher rate of smokers, worse average hygiene and higher rates of pre-existing conditions such as diabetes than women.
In the CDC study, 57% of coronavirus-infected children were male. Infected infants were also predominantly male. This "Suggests that biological factors could play a role in any difference in susceptibility to sex", wrote the study authors.
Need even more insight
Despite being the largest research carried out so far, this too is preliminary. The authors are working with limited information. Among the 2.572 pediatric cases they analyzed, only the 9,4% it also included information on patient symptoms and only the 33% indicated whether or not they had been hospitalized.
"We have to be very cautious overall," Maldonado told Time. "We still don't know what we're dealing with here."