Ваксинираните предават много по-малък вирусен товар.
Веднъж заразени, в преобладаващия брой от случаите ваксината редуцира вирусния товар, най-общо казано.
Сега, за тази мантра дали има доказателства, чакам да си кажете. Сержантът поне стъпва леко и меко на пръсти, както виждам :)
Една статия в The Lancet Infectious Diseases отпреди няколко дни:
Community transmission and viral load kinetics of the SARS-CoV-2 delta (B.1.617.2) variant in vaccinated and unvaccinated individuals in the UK: a prospective, longitudinal, cohort study
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(21)00648-4/fulltext#back-bib17Изследвана е трансмисията на делта варианта във Великобритания. Правят се сравнения ваксинирани-неваксинирани, възрастови групи, как варира вирусния товар вкл. в семейна среда.
Нещо интересно от методиката, в сравнение с някои предишни изследвания:
However, we sampled contacts daily, regardless of symptomatology, to actively identify infection with high sensitivity. By contrast, symptom-based, single-timepoint surveillance testing probably underestimates the true secondary attack rates (SAR), and potentially also overestimates vaccine effectiveness against infection.
И някои резултати, касаещи специално трансмисията и вирусния товар:
- We identified similar secondary attack rates (SAR) (25%) in household contacts exposed to fully vaccinated index cases as in those exposed to unvaccinated index cases (23%). This finding indicates that breakthrough infections in fully vaccinated people can efficiently transmit infection in the household setting.
- We found no evidence of variation in peak viral load by variant or vaccination status, but we report some evidence of modest but significant (pp=0·95) increases in peak viral load with age.
- Vaccination reduces the risk of delta variant infection and accelerates viral clearance. Nonetheless, fully vaccinated individuals with breakthrough infections have peak viral load similar to unvaccinated cases and can efficiently transmit infection in household settings, including to fully vaccinated contacts. Host–virus interactions early in infection may shape the entire viral trajectory.
