We all know that kids seem protected against the coronavirus (SARS CoV-2) that causes COVID-19 disease. They rarely get ill, although there are reports of serious and deadly disease. A different issue, is whether children can be asymptomatic carriers of the virus and spread the disease to other age groups which are more likely to get seriously ill. It is a big issue since many communities are considering opening up the schools, especially for younger children, whose parents need to go back to work.
One question arose: might infected kids produce less virus than infected adults? This has now been addressed in an interesting paper from German/British Virology labs:
An analysis of SARS-CoV-2 viral load by patient age. By Terry C. Jones et al.
They examined viral load by real-time RT-PCR threshold cycle values (which is a relatively sophisticated method. And they looked at 3,712 COVID-19 patients of all ages.
They found no significant difference between any age categories including children: the viral loads in the very young did not differ significantly from those of adults:
This graph shows that patients (each represented by a single dot) spanned a spectrum of different viral loads (Y-axis) from log 104 to log 1012. That is a huge variation in viral load (which is expected) but importantly there is no statistical difference between any of the age groups (X-axis).
Note that the numbers of dots are less dense for kids up to 20 years-old and for 91-100 year-old persons. That is simply because there were fewer individuals in these age groups.
Patients were recruited From Jan.26 through April, 26, 2020: 59,831 patients in total, 3,712 (6.2%) had a positive RT PCR test.
Note that these individuals included all comers, both symptomatic and asymptomatic.