Originally Posted by
5khours
“Even if you do get a breakthrough infection when you’re vaccinated, the chances of your transmitting it to someone else is exceedingly low….
To clarify "exceedingly low"
Background Rationale and Evidence for Public Health Recommendations for Fully Vaccinated People
- Data were added from studies published since the last update that further demonstrate people who are fully vaccinated with a currently authorized mRNA vaccine are protected against asymptomatic infection and, if infected, have a lower viral load than unvaccinated people.
But to also add variants might have higher viral load and mutations which might be stickier.
https://www.news-medical.net/news/20...iral-load.aspx
B.1.617.2 might also be dominating over the B.1.1.7 variant in the UK where it probably had more traction (aka "sticky variant", aka "Kent variant")
https://www.bbc.com/news/health-57157496
Could be the difference in AstraZeneca vaccine efficacy against B.1.1.7 1st dose 50% vs B.1.617.2 1st dose 33% (This may not be peer reviewed yet)
https://www.bbc.com/news/uk-57214596
https://www.bmj.com/content/373/bmj.n1346
2nd dose improves the odds greatly
A preprint paper released by Public Health England on 22 May showed that between 5 April and 16 May the Pfizer vaccine was 88% effective, two weeks after the second dose, against the B.1.617.2 variant and 93% against B.1.1.7, known as the UK or Kent variant.
1 The AstraZeneca vaccine was 60% effective against B.1.617.2 at two weeks after the second dose and 66% against the Kent variant.But both vaccines were only 33% effective against symptomatic disease from B.1.617.2 three weeks after the first dose, whereas they were 50% effective against B.1.1.7.
TL;DR - CDC is going by social science to hopefully encourage vaccinations and not quantified medical studies, yet. Still, the hospitalization and death counts have been better in U.K. and U.S. Different states also have different precautions (still) which are probably helping while vaccination seems to do the heavy lifting.