Thread by @EmpireinWinter

Lancet:
'Breakthrough Delta variant infections following Oxford-AstraZeneca vaccination may cause asymptomatic or mild disease, but are associated with high viral loads, prolonged PCR positivity and low levels of vaccine-induced neutralizing antibodies.'
thelancet.com/journals/eclin…

'Epidemiological and sequence data suggested ongoing transmission had occurred between fully vaccinated individuals. '

'our study also showed no correlation between neutralizing antibody levels at diagnosis and the development of symptoms.'

'Collectively, while neutralizing antibodies might be a surrogate of protection, especially against severe diseases as a whole [[24]], they might not be good indicators of infection progression and infectiousness for breakthrough Delta variant infection. '

'we found viral loads of breakthrough Delta variant infection cases were 251 times higher than those of the infected cases detected during the early phase of the pandemic in 20207, with high viral loads recorded around 2-3 days before and after the development of symptoms.'

'Notably, a recent report from the US showed comparable viral loads between vaccinated and unvaccinated individuals infected with the Delta variant.[5]'

'Collectively, high viral loads might explain the current rapid expansion of the Delta variant, even in the countries with high vaccination coverage.'

'Additionally, previous reports showed short duration of PCR positivity or culturable viruses (2–7 days after diagnosis) among breakthrough infections [[26],[27]]. In contrast, we found prolonged PCR positivity was up to 33 days in our study participants.'

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