SARS-CoV-2 viral load distribution in different patient populations and age groups reveals that viral loads increase with age.
https://www.medrxiv.org/content/10.1101/2021.01.15.21249691v1
These data present reveal a clear relation between age and SARS-CoV-2 viral load, with especially children aged<12 years showing lower viral loads than shown in adults (β: -0.03, 95CI% -0.03 to -0.02, p<0.001), independent of sex and/or symptom duration. Interestingly, the median Cp values between the oldest (>79 years) and youngest (<12 years) population differed by over 4 PCR cycles, suggesting approximately a 16 fold difference in viral load
Conclusion: We observed that in patients tested by public health services, SARS-CoV2 viral load increases significantly with age. Previous studies suggest that young children (<12 years) play a limited role in SARS-CoV-2 transmission. Currently, the relation between viral load and infectivity is not yet well understood, and further studies should elucidate whether the lower viral load in children is indeed related to their suggested limited role in SARS-CoV-2 transmission. Moreover, as antigen tests are less sensitive than PCR, these results suggest that SARS-CoV-2 antigen tests could have lower sensitivity in children than in adults.
