Thread by @sailorrooscout

A study out of Harvard shows while breakthrough infections with Delta have similar peak viral loads (Ct) to that of unvaccinated individuals, viral loads decrease faster in vaccinated individuals AND they are contagious for a SHORTER period of time, and harbor less virus overall.

Researchers quantified the course of viral proliferation and clearance for 173 individuals with acute SARS-CoV-2 infections using longitudinal quantitative RT-PCR tests conducted using anterior nares/oropharyngeal samples (n = 199,941) as part of the National Basketball

Association’s (NBA) occupational health program between November 28th, 2020, and August 11th, 2021. Researchers then measured the duration of viral proliferation and clearance and the peak viral concentration separately for individuals infected with Alpha (B.1.1.7), Delta

(B.1.617.2) and non-variants of interest/variants of concern (non-VOI/VOC), and for vaccinated and unvaccinated individuals. What they found was that mean viral trajectories of Alpha and Delta infections resembled those of non-VOI/VOC infections. Vaccine

breakthrough infections exhibited similar proliferation dynamics as infections in unvaccinated individuals (mean peak Ct: 20.5, vs. 20.7, and mean proliferation time 3.2 days vs. 3.5 days; HOWEVER vaccinated individuals exhibited faster clearance (mean clearance time: 5.5 days

vs. 7.5 days. REMEMBER: Ct values/concentrations ARE NOT a measure of INFECTIOUSNESS. In other words, vaccinated individuals ARE NOT as likely to spread the coronavirus as unvaccinated individuals.

So, let’s talk about that because there is a lot of misinformation circulating recently. “Vaccinated people are just as likely to spread the coronavirus. This misunderstanding, born out of confusing statements from public-health authorities and misleading media headlines,

is a shame. It is resulting in unnecessary fear among vaccinated people, all the while undermining the public’s understanding of the importance-and effectiveness-of getting vaccinated. So let me make one thing clear: Vaccinated people are NOT as likely to spread the coronavirus

as the unvaccinated. Even in the U.S. where more than half of the population is fully vaccinated, the unvaccinated are responsible for the overwhelming majority of transmission. Despite concerns about waning immunity, vaccines provide the best protection against infection.

And if someone isn’t infected, they can’t spread the coronavirus. It’s truly that simple. Additionally, for those instances of a vaccinated person getting a breakthrough case, yes, they can be as infectious as an unvaccinated person. But they are contagious for a shorter period

of time when compared with the unvaccinated, and they harbor less infectious virus overall. That’s why getting more people their shots is crucial for controlling the spread of the coronavirus. Every vaccinated person helps limit the virus’s ability to hide, replicate,

and propagate. Among the unvaccinated, the virus travels unhindered on a highway with multiple off-ramps and refueling stations. In the vaccinated, it gets lost in a maze of dead-end streets and cul-de-sacs. Every so often, it pieces together an escape route, but in most

scenarios, it finds itself cut off, and its journey ends. It can go no further. Everyone knows that the vaccines help protect each individual who gets their shots. But when more people get vaccinated, this helps keep everyone else safe as well.”

You can read all of this and more here: theatlantic.com/ideas/archive/… and find this study here: medrxiv.org/content/10.110…