Lunchtime pandemic reading.
Standard disclaimer: this is a roundup of informative pieces I've read that interest me on the severity of the crisis and how to manage it. I am not a qualified medical expert in ANY sense; at best I am reasonably well-read laity. ALWAYS prioritize advice from qualified healthcare experts over some person on Facebook.
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Relaxing restrictions raises herd immunity thresholds. "1) Good thread on the potential US pandemic endgame. Carl is stressing the importance of "overshooting"; that the wave does not miraculously collapse once Herd Immunity Threshold (HIT) is reached but still has enough steam to go above 60% infected. Below a more optimistic take.
2) Carl makes it very clear that he's using the basic SEIR model for his account, which features only one large wave along which the HIT is reached and the wave starts declining - entailing many more infections though. What changes if we have had multiple waves instead of one?
3) That's my crappy MSWord depiction. The US has had several waves (red) that together with vaccines have brought the level of immunity to maybe 50% now (the cumulative curve in black). So we're hopefully close to the HIT and current infections are low (for US standards).
4) So the next wave could reach the HIT without building up a lot of momentum (dashed blue curve) and decline from there on. There would still be overshooting but less than in the basic model. Would roughly fit historical pandemics but now with vaccines ...
5) ... that prevent many deaths. However, and that's what Carl is stressing, relaxing NPIs would almost certainly push up the HIT. Hence a bigger wave could follow (dashed red curve). So the point that reopening too early will likely make the endgame worse holds in any case.
6) What odds to asign to the "good" and the "bad" US endgame scenarios? There's no math behind my guess, but I would say 50/50. Which seems more optimistic than most guesses about how things will play out. Funny enough, this discussion from 11 months ago:
7) Clearly, nothing here has a lot of relevance for continental Europe because these countries are nowhere near the HIT; Both their infection and their vaccination rates have been lower than in the US, making the endgame longer and probably more risky. "
Source:
Commentary: What I'd personally like to see is mask wearing become the default, especially in the cooler seasons. COVID-19 will become endemic, just as influenza has, and will be something we need to live with as a species. If we pivot like many East Asian countries and just start wearing masks as a general rule, we'll not only keep COVID-19 suppressed, but also do a lot to diminish the impact of the flu and common colds. Certainly, once we've hit herd immunity, we can do things like eat in restaurants and go to events, etc. but casually? On mass transit? In airplanes? I see no reason to stop wearing a mask.
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Ventilation is everything. "An outbreak of severe acute respiratory syndrome coronavirus 2 infection occurred among church attendees after an infectious chorister sang at multiple services. We detected 12 secondary case-patients. Video recordings of the services showed that case-patients were seated in the same section, >15 m from the primary case-patient, without close physical contact, suggesting airborne transmission."
Source: https://wwwnc.cdc.gov/eid/article/27/6/21-0465_article
Commentary: For the Imperial-minded, 15 meters is 49 feet. COVID-19 was contagious in a church over 49 feet away from the spreader. Not only does this reinforce our knowledge of airborne transmission, but it emphasizes just how critical ventilation is.
49 feet - 16.3 yards, 15 meters - is the length of the penalty area and then some in a soccer field. It's the distance from the 15 yard line to the end zone in American football. That's a LOT of distance - far more than the 6 foot rule.
The new variants, in particular B.1.1.7, are much more contagious. Wear a mask, but also stay out of indoor spaces that aren't your home. Even after you've been vaccinated, keep your time indoors in places that aren't your home to a minimum.
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Kids transmit COVID-19 more than previously thought. (preprint) "RESULTS A total of 6,280 households had pediatric index cases, and 1,717 (27.3%) experienced secondary transmission. Children aged 0-3 years had the highest odds of household transmission compared to children aged 14-17 years (model adjusted for gender, month of disease onset, testing delay, and average family size: 1.43, 95% CI: 1.17-1.75). This association was similarly observed in sensitivity analyses defining secondary cases as 2-14 days or 4-14 days after the index case, and stratified analyses by presence of symptoms, association with a school/childcare outbreak, or school/childcare reopening. Children aged 4-8 years and 9-13 years also had increased odds of transmission (4-8: 1.40, 95% CI: 1.18-1.67; 9-13: 1.13, 95% CI: 0.97-1.32).
CONCLUSIONS This study suggests that younger children are more likely to transmit SARS-CoV-2 infection compared to older children, and the highest odds of transmission was observed for children aged 0-3 years. Differential infectivity of pediatric age groups has implications for infection prevention controls within households, as well as schools/childcare, to minimize risk of household secondary transmission."
Source: https://www.medrxiv.org/content/10.1101/2021.03.29.21254565v1
Commentary: Childcare settings might be responsible for the higher infectivity rates among young children, but schools are also part of the mix. Anyone who says schools aren't methods of transmission isn't paying attention to evidence and common sense.
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A reminder of the simple daily habits we should all be taking.
1. Always wear the best mask available to you when out of your home and you'll be around other people. Respirators are back in stock at online retailers, too. Wear an N95/FFP2/KN95 that's NIOSH-approved or better mask if you can obtain it. If you can't get an N95 mask, wear a surgical mask with a cloth mask over it.
2. Get vaccinated as soon as you're able to.
3. Wash/sanitize your hands every time you are in or out of your home for any reason.
4. Stay home as much as possible. Minimize your contact with others and maintain physical distance of at LEAST 6 feet / 2 meters, preferably more. Avoid indoor places as much as you can; indoor spaces spread the disease through aerosols and distance is less effective at mitigating your risks.
5. Get your personal finances in order now. Cut all unnecessary costs.
6. Replenish your supplies as you use them. Avoid reducing your stores to pre-pandemic levels in case an outbreak causes unexpected supply chain disruptions.
7. Ventilate your home as frequently as weather and circumstances permit, except when you share close airspaces with other residences (like a window less than a meter away from a neighboring window).
8. Masks must fit properly to work. Here's how to properly fit a mask:
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Common misinformation debunked!
There is no mercury or other heavy metals in the Pfizer mRNA vaccine. https://www.technologyreview.com/2020/12/09/1013538/what-are-the-ingredients-of-pfizers-covid-19-vaccine/
There is no genomic evidence at all that COVID-19 arrived before 2020 in the United States and therefore no hidden herd immunity:
Source:
There is no evidence SARS-CoV-2 was engineered, nor that it escaped a lab somewhere.
Source: https://www.washingtonpost.com/world/2020/01/29/experts-debunk-fringe-theory-linking-chinas-coronavirus-weapons-research/
Source: https://www.nature.com/articles/s41591-020-0820-9
Source: https://www.nationalgeographic.com/science/2020/05/anthony-fauci-no-scientific-evidence-the-coronavirus-was-made-in-a-chinese-lab-cvd/
There is no evidence a flu shot increases your COVID-19 risk.
Source: https://www.factcheck.org/2020/04/no-evidence-that-flu-shot-increases-risk-of-covid-19/
Source: https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa626/5842161
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A common request I'm asked is who I follow. Here's a public Twitter list of many of the sources I read.
https://twitter.com/i/lists/1260956929205112834
This list is biased by design. It is limited to authors who predominantly post in the English language. It is heavily biased towards individual researchers and away from institutions. It is biased towards those who publish or share research, data, papers, etc. I have made an attempt to follow researchers from different countries, and also to make the list reasonably gender-balanced, because multiple, diverse perspectives on research data are essential.
This is also available as an email newsletter at https://lunchtimepandemic.substack.com if you prefer the update in your inbox.