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Post-pandemic adjustments: Air exchange rates
#1
I was given tickets to a comedy show at Alameda Comedy Club and, with hesitation, went to the show.  There was a minimum purchase of food (or drink?), thus requiring people to have their masks off at some point.  I know that's a way for the venue to make money separately from tickets and tips.

Alameda (1.0% positivity, 2.9/100K 7 day) is in California's orange tier, which allows such venues to have indoor shows (it would have been uncomfortably brisk outdoors).  From what was said, I believe they were allowed to seat 40% of capacity.  People were at tables of 2 or 4, with about 6' between tables.   Masks were required at entry, with temperature checks.   AFAIK, there was no confirmation that guests were vaccinated.   It is unclear to me whether this venue would be considered a Live Event, a Restaurant, or a Private Event.  The requirements on each are different.  (Why not a restaurant?  Probably < 50% of the revenue is from food (separating out alcoholic beverages and ticket prices.)  Differently than a true restaurant, all their business is consolidated into a single time period, and the time spent by patrons is extended by the performance rather than just 15-30 minutes of eating.)  Judging from the room occupancy, they apparently were operating as a restaurant, at 50% of capacity (and, IMO, the riskiest of the alternatives as it encourages the removal of facemarks).

Before the show, there were maybe 12% of the tables without masks, before food or drink was served.  During the show, when people were not actively eating or drinking, maybe 12% of the tables had masks on.  While there was a sign up before entering the venue, I saw no attempt to enforce guidelines:  There were no reminders from wait staff and no announcement from the venue (by loudspeaker or those on stage). There was no verbal reminder at the door.

The venue gives notice that they improved their air handling to provide 4 air changes per hour.  Indeed, an exchange rate of 17 minutes (not quite 4 per hour) was brought up by one performer, who seemingly ridiculed it as "being a good idea when in the red [tier]".  This is the minimum per the state of California for rooms with marginal ventilation.  (I tried to find the building codes or standards for such commercial spaces but they all seemed to be behind a pay wall.  The "recommendations" at Wikipedia are not documented, but for reference, they are:  public auditoriums: 12-18 ACH;  restaurant dining area: 8-10 ACH)


(A reminder: The Governor of California founded a group of wineries, restaurants, and venues. His sister is now co-president of that group.)
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#2
I am not ready to go to these types of venues. Too many unknowns, especially vaccine status. I have had a small number of vaccinated friends over to our home, including one well known Stanford sports poster from another board. But it has been minimal.

On the other hand, if everyone in the facility is immunized, the risk of transmission is probably really low. In the real world the vaccines are working unbelievably well in stopping serious illness.

As news gets out to teenagers that they can see their friends if they get vaccinated, the number of kids I see who are resistant to getting the vaccine has dwindled to almost nothing. We're immunizing a ton of kids. I think we get to 70% coverage in California this fall. Once we can immunize younger kids hopefully 75%. Hard to imagine we will get much higher.
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#3
Encouraging that teens are getting vaccinated!   Given that so much disease transmission happens in schools and activities, this seems important to minimize cases this coming academic year
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#4
(06-05-2021, 04:09 AM)akiddoc Wrote: the number of kids I see who are resistant to getting the vaccine has dwindled to almost nothing. We're immunizing a ton of kids. I think we get to 70% coverage in California this fall. Once we can immunize younger kids hopefully 75%. Hard to imagine we will get much higher.

That's great news!  Right now I don't have any contact with teens or even young (20ish) adults so I had no idea how it might vaccination might be viewed.  Furthermore, since I know you do a lot (all?) of your work in disadvantaged areas, this is encouraging that we aren't having a "We don't trust the establishment" reaction.

Wow, Alameda County is doing a lot better in that age group than the US or California.  46.2% of 12-17yo have had at least one vaccination.   So, maybe what akiddoc is seeing doesn't yet apply to the rest of the state or country.

The CDC data indicate these percentages of US residents that have at least one dose:
June 5 data (May 29 data, delta in that week)
0-11:  0.3%  (0.2%)
12-15: 21.3% (18.3% +3.0%)
16-17: 37.5% (35.8% +1.7%)
18-24: 44.3% (42.9% +1.4%)
25-39: 50.1% (49.0% +1.1%)
40-49: 59.8% (58.7% +1.1%)
50-64: 70.5% (69.6% +0.9%)
65-74: 87.9% (87.4% +0.5%)
75+: 84.2%  (83.9% +0.3%)

California 
June 1 data (May 25 data)
12-17: 30.8% (27.8%  +3.0%)
18-49: 60.2% (58.7% +1.5%)  (Good!    L.A. Co. is 61.4%)
50-64: 75.9% (75.1% +0.8%)
65+: 77.3% (76.9% +0.4%)   (Not good!   L.A. Co. is 69.9%)

Interesting that California is doing much worse than the US in the 65+ age group (something like 1.5x unvaccinated rate)
but a lot better in the 18-49 age group.  (I wonder if that better coverage in 18-49 could be the reason that CA has the lowest infection rate among the US states, even though CA doesn't have the highest rate of 1+ vaccines over all ages.)

(This confused me for a bit.  The California stats page has a "Proportion of first vaccine doses by group" section.  For age for Alameda Co. (for instance), it shows 5.4% by 12-17yo.  That means the that age group represents 5.4% of all those with at least one vaccination. NOT that 5.4% of that age group has at least one vaccination.)

There's a page at the CDC
  https://covid.cdc.gov/covid-data-tracker...ccinations
that has a lot more than global vaccinations, and allows comparing the US to elsewhere.

P.S.  Darn, it seems CA didn't contact me as being a winner of the first round of the vaccination lottery.  Well, by getting the vaccine, I won anyway.
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#5
Quote:That's great news!  Right now I don't have any contact with teens or even young (20ish) adults so I had no idea how it might vaccination might be viewed.  Furthermore, since I know you do a lot (all?) of your work in disadvantaged areas, this is encouraging that we aren't having a "We don't trust the establishment" reaction.


Perhaps someone treats his clients with respect and has gained their trust?

I find it really offensive when people say things like "why are they so stupid?" I know that it is based in anger because the speaker feels that these people are putting them at risk. Being called stupid when you are not does not convince one to get a vaccination. Even the Washington Post seems to imply something is wrong if someone does not get vaccinated. If a person does not get the vaccine due to political affiliation, that is sad. If the person performs a risk assessment and decides to decline, we have to accept it. 

My favorite coronavirus podcast, Das Coronavirus Update, had a guest speaker. The podcast is remarkably apolitical and features very well respected experts. The EU (EMA) recently recommended authorization of an mRNA (Pfizer/Biontech, called "Comirnaty" over there) vaccine for 12+. The guest speaker works at the government agency that makes recommendations. He said that Germany would not recommend it for 12-15 year olds. His cited reasons include risks from the vaccine:
  • myocarditis and pericarditis,
  • cerebral venous sinus thrombosis,
  • lack of long term observations.
So this confused me. The first risk may come from one vaccine, the second from AZ or JJ which was not part of the recommendation. (The interview was conducted virtually and he had less than perfect enunciation and equipment. Perhaps they authorized AZ as well.) He also said that there was no safety study, just a study on the effectiveness of the vaccine. The numbers were so low, 1100 in each of the placebo and test group, that even relatively high incidence short term effects could go unnoticed. He noted that the observation period ranged from 1 to 2 months. He said that MIS-C was an important side effect from the disease, but was treatable and expected to lead to good outcomes.  He noted that Germany, a country of 83 million had 2 deaths of people in this age group. Both were at the end stage of a different, terminal disease. He noted that more kids in this group end up in ICU than expected, but there is a bias to put kids in ICU earlier due to emotional impact of kids that are sick. (Lots of paraphrasing here). I was disappointed that he did not mention the long covid risk. He did mention that doctors could still give vaccinations to this age group based upon individual circumstances (co-morbidities, the need to protect immunocomprimised family members, etc.)

I think it is refreshing to hear a health official state that "safe" means "safe from short term effects". Part of the calculus here is that the risks of covid are lower for this age group and using a vaccine with unknown risks may or may not help overall. Do no harm. I do not feel that the CDC messaging is honest about the unlikely possibility of long term effects and that this will degrade trust. The guest speaker said that they were looking at the situation from what is best for the kids, not general public health. That is a tough balance. The US is on the public health side, from what I gather. 

The interviewer asked, when the unvaccinated kid gets covid and gives it to their 40 year old parent, then what? His answer reflects the state of vaccination in Germany: You have to start to vaccinate the 40+ before thinking of vaccinating the kids with the exception of co-morbidities. 

In summary, if I had kids between 12 and 15 I would go obsessive trying to learn the pros and cons, make a list, and then go to the doctor. I would not walk up to a clinic with them today and just get a shot. Yes, there is a balance between individual health and public health with vaccines, but the risks remain unclear.
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#6
I found thinking through the comedy club scenario interesting with some unique considerations.

Comedy clubs are usually small, packed, with low ceilings and brick walls (so you’re breathing other people’s air) and poor spacing, even at 50% capacity, and people are drinking, often a lot.

On the one hand, unlike a call center or a choir, there’s only one person doing most of the talking — the comic. On the other hand, if the comic is funny, people are laughing. I don’t know of a study covering how much we expectorate when we laugh, but I’d “expect” it’s a lot.

We often consider factors like indoor/outdoor, masks, open walls/windows, air exchanges, ventilation, and spacing — which we should. But I think we also should regularly consider how many people are expectorating, how much they are expectorating, and the demographics of the people there.

For example, I’d feel safer at a high-ceiling conference hall with 2,000 masked sober people taking notes than with 200 laughing, drunk, young people in a comedy club dungeon. I plan to watch movies this summer and I suspect movies are safer than indoor restaurants. Even though there are more people in a theatre and the exposure is more prolonged (2 hours), even if people somtimes take of their masks to eat popcorn, at least they aren’t talking (or they shouldn’t be). I’d rather be in a high-ceiling movie theatre with spaced out luxury recliner chairs with 500 silent people for 2 hours than in a noisy indoor restaurant with 100 people for an hour. I suspect there’s so much spread at restaurants not just because people take off masks to eat (although that certainly sets the stage) — it’s because we often go to restaurants and bars to talk.

By this line of reasoning, if you are indoors and someone nearby is coughing persistently, you should move or exit.

When considering activities, although we talk about choirs and call centers, I haven’t seen us regularly factor how much people are expectorating (sneezing, coughing, talking, laughing, cheering or singing), and I think we need to.
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#7
at my workplace I am pushing hard for a firmer line if anyone is sneezing or coughing, work from home.  As remote work has advanced, this becomes much easier.
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#8
Snorlax, good thoughts, which I didn't consider. (I only knew about the tickets 2 days before the event. Frankly, I didn't know what the spacing would be, or the nature of the venue)

I've often thought about sporting events where there is cheering or yelling going on. Fortunately, most of those are either outdoor or have high ceilings. Still, I wonder if the Indianapolis area is having a bit of a surge from the outdoor & spaced Indianapolis 500. Restrooms & concessions likely are places where people will get close together. (Restrooms will have high exchange rates.)
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#9
(06-05-2021, 06:32 PM)M_T Wrote: The CDC data indicate these percentages of US residents that have at least one dose:
...
California 
June 1 data (May 25 data)
12-17: 30.8% (27.8%  +3.0%)
18-49: 60.2% (58.7% +1.5%)  (Good!    L.A. Co. is 61.4%)
50-64: 75.9% (75.1% +0.8%)
65+: 77.3% (76.9% +0.4%)   (Not good!   L.A. Co. is 69.9%)

Interesting that California is doing much worse than the US in the 65+ age group (something like 1.5x unvaccinated rate)
but a lot better in the 18-49 age group.  (I wonder if that better coverage in 18-49 could be the reason that CA has the lowest infection rate among the US states, even though CA doesn't have the highest rate of 1+ vaccines over all ages.)
Just after I wrote this, an article in the SJMN used a very different % for 65+ (91%).  I challenged the author who indicated he got it from the CDC.

I then found the data at the CDC.  The difference is that CA calculated their numbers with a state population of 65+ as about 6.6M while the CDC used 5.8M.  The total population numbers differed significantly for the 18-49 age group as well, with CA using 16.9M while the US Census shows about 19M.  

If the Census numbers are right, then that explains why 18-49 looks good and 65+ looks bad.

For 65+, CDC has
5,341,677 with one dose (91.5%)
4,274,315 fully vaccinated (73.2%)  That's a huge gap.
out of roughly 5,838,000

The state shows
5,155,340 with one dose (77.7%)  That's a more reasonable gap between partial & fully vaccinated.
4,395,179 fully vaccinated (66.2%)
out of 6,638,564

I've given feedback on the CA webpage to point out the difference in total population.
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#10
In addition to population differences, there also seem to be some vaccinations that don't show up in the California state numbers. The Contra Costa County vaccination dashboard has the following note:

Quote:May 17, 2021: We have made some changes to this dashboard to improve our data for vaccinations. Previously, we displayed demographic data solely from the California Immunization Registry (CAIR). In cases where Contra Costa Health Services has local immunization records and demographics not available in CAIR, we are using that local data to supplement what is in CAIR to provide more accurate information on the vaccine dashboard. As a result, there are now a higher number of vaccinations shown for several ethnicity and race categories, particularly among Whites and Asians. In addition, we have added about 18,000 vaccinations for which we have local records that are not in CAIR.  
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