Expert Reaction to Questions about COVID-19 and Viral Load | Science Media Centre
MARCH 24, 2020
The total amount of virus a person has inside them is referred to as their ‘viral load’.
The amount of virus that an infected individual is producing – sometimes referred to as the viral load – and potentially shedding, will also impact on transmission; the higher the viral load the more infectious someone is likely to be.
There have been questions from journalists about viral load ad the COVID-19 outbreak.
The virus load in patients infected with COVID-19 appears to be highest during the early stages of infection.
Doctors who have to get very close to patients to take samples from them or to intubate them are at higher risk so need to wear masks.
Dr Edward Parker, Research Fellow in Systems Biology at the London School of Hygiene and Tropical Medicine, said:
“After we are infected with a virus, it replicates in our body’s cells.
The total amount of virus a person has inside them is referred to as their ‘viral load’. For COVID-19, early reports from China suggest that the viral load is higher in patients with more severe disease, which is also the case for Sars and influenza.
Prof Jonathan Ball, Professor of Molecular Virology, University of Nottingham, said:
“We know that the likelihood of virus transmission increases with duration and frequency of exposure of an uninfected individual with someone infected with the virus. We also suspect that
the amount of virus that an infected individual is producing – sometimes referred to as the viral load – and potentially shedding, will also impact on transmission; the higher the viral load the more infectious someone is likely to be.
“It is also possible that individuals with pneumonia who have a higher viral load might develop more serious disease, but disease development is complex and no doubt many factors will have an impact.”
