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A New Zealand doctor says the medical fraternity are trying to discover why children seem much less vulnerable to Covid-19 and that they may have a partial immunity to it.
A nurse Yang Liu receiving a painting as a gift from a child infected with novel coronavirus pneumonia at a ward in Wuhan Children's Hospital in Wuhan. Photo: AFP
Dr Michelle Dickinson told Nine to Noon statistics on those affected by the coronavirus show some groups more or less susceptible, according to age and even gender.
As the virus spreads around the world, facts are emerging and the nature of Covid-19 is becoming clearer to researchers and doctors treating it.
Dr Dickinson said figures released by the World Health Organisation showed some interesting trends in the distribution of the virus among the general population and the effects it was having on different groups.
"The data shows that people who are aged 30 and over are much more susceptible and data out of China shows 87 percent of people aged 30-to-79," she said.
"It definitely seems to be skewed to an adult disease, rather than one affecting children."
There have been no deaths in children under 9 and only 2.4 percent of cases of the virus have been identified in under-19 age bracket. Just 2.5 percent of these cases have been severe.
"What seems to be happening is children have less symptoms... We don't know why that is, but we do know that the immune system of children can actually be slightly different to adults," she said.
"We see that with chicken pox. If you get chicken pox as adults it's much more severe than when you had chicken pox as a children."
She said one theory being probed by medical researchers was that children had already been exposed to different types of coronavirus viruses in schools and kindies, so that they may be benefiting from a type of developed cross-over immunity.
"What is clear though is they are probably still big carriers and they're likely to be more 'super-spreaders', especially if they are still going out to play if they aren't very sick. It doesn't seem to affect their lungs as much as it does in adults."
Eighty percent of overall cases are mild-to-moderate, according to statistics by the World Health Association (WHO). Severe cases make up 13.8 percent of those with the illness, while 6.1 percent of cases are considered critical.
She said the statistics also pointed to a slight variance in susceptibility according to gender.
"For every 106 men who are affected there are only 100 women affected. That's only a 51 percent, but what's interesting is mortality rates. It's definitely more severe in men than women. Of the men affected, almost 2.8 percent of the men died, whereas only 1.7 percent of the women died," she said.
"However, the men tended to have more pre-existing conditions, so heart attacks and heart problems, hepatitis B."
Pregnant women do not seem to be at a higher risk.
There are now three confirmed cases of coronavirus here in New Zealand - while globally more than 90,000 people have been infected.
The cases here are in people who've travelled from overseas countries experiencing an outbreak.