Let’s talk about viral loads. Do unvaccinated people infected with the delta variant show higher loads than we see with other variants?https://www.colorado.edu/today/2021/08/05/7-common-questions-about-delta-variant-what-research-says
When it comes to COVID-19, a higher viral load seems to lead to a higher risk of transmitting the disease. Reports suggest that unvaccinated people infected with the delta variant have a roughly 1,000-fold higher viral load than with the original strain of SARS-CoV-2 (which now accounts for a minority of cases in the U.S). The delta variant also seems to generate about a five- to 20-fold higher viral load than alpha, a variant first identified in the United Kingdom.
What about vaccinated people? Do they also have higher viral loads?
There are also multiple sources that support this claim. One estimate indicates that vaccinated people infected with the delta variant have a viral load that’s five or six times higher than what we see in breakthrough infections from other variants. This makes sense because the mutations that gave rise to delta lead to higher viral loads in general.
Some news stories have gone beyond that—suggesting that the viral load in breakthrough cases of delta isn’t just high. It’s equal to the loads seen in cases among unvaccinated people. What does the evidence show?
This claim has caused a lot of concern in recent weeks because it suggests that the protection offered by COVID-19 vaccines is eroding. It’s primarily based on a CDC report that described an outbreak in Barnstable County, Massachusetts. In that case, researchers tested infected individuals for a parameter called CT, which indicates the presence of viral RNA and is often taken as a proxy for viral load. However, there are several issues that complicate the interpretation of those data, some of which are acknowledged in the report.
What are some of those issues?
Before vaccines, CT was a reasonable proxy for viral load. But it’s unclear if that’s the case for vaccinated individuals. When an individual mounts a successful immune response, infectious virus is destroyed, but RNA may remain. That explains why you may continue to test positive for COVID-19 months after you recover and are no longer a risk to others.
We don’t yet know whether vaccine breakthrough cases are truly shedding high levels of infectious virus. The Barnstable report clearly states that the test results could be “affected by factors other than viral load” and that “microbiological studies are required.”
Additionally, in a yet-to-be published report from Singapore, breakthrough infections in vaccinated individuals achieved similar CT values to unvaccinated cases, but only for a brief amount of time. Vaccinated people were able to clear the virus much faster than unvaccinated people. Another study out of Imperial College London in the United Kingdom examined nearly 100,000 people from England between June 24 and July 12, 2021 (when delta was the dominant variant). It found that vaccinated individuals had a lower viral load on average compared to unvaccinated individuals.
So is the jury still out?
We can’t rule out that vaccinated people can shed high levels of the delta variant, but the current evidence doesn’t allow us to make a firm conclusion.
How common are breakthrough cases among vaccinated people?
It’s important to consider vaccination rates when asking this question. Look at Boulder County, for example. Close to 100% of individuals over the age of 75 in Boulder County have received at least one dose of a COVID-19 vaccine. In this extreme scenario, nearly all cases that occur in people over the age of 75 will be breakthrough infections even though their occurrence is uncommon overall.
Have breakthrough cases become a major driver of the pandemic?
There is no available evidence to support this. We know that risk of infection is lower among vaccinated versus unvaccinated individuals. We still see that highly vaccinated communities tend to have low rates of transmission compared to under-vaccinated communities.
We need to do more work before we know how much risk relatively uncommon breakthrough infections pose for spreading the virus.
How long do vaccines work?
While booster shots may ultimately be necessary, data show that vaccines continue to offer excellent protection even six months after being vaccinated. There is some new evidence out of Israel that efficacy may wane over time in certain groups, such as immunocompromised people and the elderly.
Given the evolving science, should people wear masks, even if they’re vaccinated?
The effectiveness of universal masking depends on a lot of factors, including the level of immunity in a given community, compliance with mask adoption as well as the quality of masks used. What hasn’t changed is that the best protection against COVID-19 is to get vaccinated.
Remember that exposure matters—both in duration and intensity of exposure. If you are in a poorly ventilated, crowded indoor environment for a long period of time where the vaccination status of people around you is unknown, wearing a mask offers another layer of protection. Of course, avoiding such environments will eliminate that exposure entirely.
Novelty=severity is an overly reductive, glib argument that doesn’t even pass lay reasoning of flu getting worse with age
The difference including the age of immune system in elderly
Cov2 ages the immune system severely
This explanation should be readily accessible to wsj and Atlantic writers and readers
Some will dismiss out of contractual obligation
Cov2 will remain a ‘superflu’ ss chris murray put it in places without therapeutics like Iranhttps://twitter.com/fitterhappierAJ/status/1444210972013604864?s=20
He was attacked for saying that too
Even though the reported number of flu-related deaths in children during the 2019-20 flu season was 199, CDC estimates the actual number of flu-related deaths in children that season was 434 when accounting for rates of influenza testing among children and deaths outside of a hospital that may be even less likely to be recognized as flu.https://www.cdc.gov/flu/spotlights/2020-2021/pediatric-flu-deaths-reach-new-high.htm
Preprint with @aashishg_ on India's pandemic excess deaths (April 20-June 21):/.../
central estimate: 3.8M
optimistic estimate: 2.8M
pessimistic estimate: 5.2M
To make these estimates we need to assess levels/ trends in mortality and death registration.
(1/5)
https://medrxiv.org/content/10.1101/2021.09.30.21264376v1
There are limitations in the data, and uncertainties, and we will update the estimates as more data becomes available. But the uncertainties do not fundamentally change the story of this huge catastrophe, and millions of uncounted deaths. (5/5)https://twitter.com/muradbanaji/status/1444292212464947205?s=20
/.../We show that the surveillance of pandemic mortality in India has been extremely poor, with around 8-10 times as many excess deaths as officially recorded COVID-19 deaths. Our findings highlight the utility of all-cause mortality data, as well as the significant challenges in interpreting such data from LMICs. These data reveal that India is among the countries most severely impacted by the pandemic. It is likely that in absolute terms India has seen the highest number of pandemic excess deaths of any country in the world.https://www.medrxiv.org/content/10.1101/2021.09.30.21264376v1
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