Notices by Jeff Gilchrist (jeffgilchrist@mstdn.science)

Ottawa Public Health makes only the raw data available for All causes and respiratory-related emergency department visits to Ottawa hospitals by age group and week ( https://open.ottawa.ca/datasets/ottawa::all-causes-and-respiratory-related-emergency-department-visits-to-ottawa-hospitals-by-age-group-and-week/about ). 2/

If I take the data and plot all the ages together, you can at least see all of the age groups at the same time but it is just the raw numbers.

The graph shows that the # of visits for the age 0-3 group is similar to the 18-54 age group near the top of the graph, and the 80+ age group numbers are very low, similar to the age 12-17 group. 3/

But you aren't seeing the full picture, this is where population rate comes in. The next graph uses the same data but instead of raw numbers shows the rate per 100,000 population in each age group.

You can see with population rate the age 0-3 group is far and above the highest level of all groups while the 18-54 age group which had similar raw numbers is actually the lowest rate. 4/

Why? The 0-3 age group represents only 3.75% of the population in Ottawa but had the same # of visits as the 18-54 age group which represents 49.9% of the population so a much higher percentage of the 0-3 age group is being impacted by respiratory infections resulting in ED visits.

Now you can see the real impact on age, where age 0-3 have the highest ED visit rate followed by age 4-11, and then age 80+ which get hidden when you only look at the raw provided numbers from OPH. 5/

Just to make things a little simpler, the last graph shows the # per 100k population as a stacked percentage so you can easily see which age groups are impacted the most.

The youngest 0-3 age group throughout the year accounts for more than 50% of all respiratory related ED visits per 100K population despite being only 3.75% of the population. 6/

Particles in between those sizes (around 0.3 microns) don't travel in straight lines and also don't zigzag randomly but get carried along with the air as it flows around fibres and likely past fibres so can possibly sneak by respirators even with multiple layers. N95s use a final trick of capturing particles of all sizes using an electric field where even neutral particles will still be attracted (as you can see from neutrally charged styrofoam sticking to a cat with static charged fur). 14/

Some cool images of particles being captured by an N95 respirator. "The 'big'' crystals are about 1.5 microns. The smaller captured particles are as small viruses like COVID." ( https://threadreaderapp.com/thread/1865453640510824790.html ). 🧵 1/

#N95 #Respirator #Virus #Filter

Clean air including ventilation and filtration is the ward that can be implemented at an infrastructure level and people don't need to do anything different to get the benefits like we already benefit from clean water infrastructure. Governments and policy makers need to put the appropriate standards and monitoring in place and then mandate them. 17/

"Learning to live with COVID" means upgrading air quality, now ( https://www.thegauntlet.news/p/learning-to-live-with-covid-means ). 18/

It is estimated that currently 1 in 13 people are infected in Ontario which means there is a 55% chance at least one person in your group of 10 is infected. This jumps to a 70% chance in groups of 15, 86.5% chance with 25 people and 98% chance at that office Christmas party of 50 people.

Estimate from ( https://covid19resources.ca/covid-hazard-index/ ) and calculator available at ( https://docs.google.com/spreadsheets/d/1qokCvvi6oRYRCKtrZuyeUmb5mt4LC9o8nKHLKoAUVAY/edit?usp=sharing ). 🧵 1/

The EPA aerosolized non-pathogenic virus (bacteriophage MS2) and measured particle size (0.01 um to 0.6 um) and concentration during the testing in a 3000 square foot test chamber. They found the virus particle concentration was reduced by 40% after 15 minutes, 97% after 30 minutes, 99.4% after 60 minutes and 99.8% after 90 minutes.

More details about this EPA CR box testing project are described here ( https://twitter.com/MarinaC_Dyb/status/1719349909210472749 ).28/

Just like we expect to have access to clean drinking water, we should be demanding that our governments also provide access to clean air.

Recently 60-Minutes did an episode on The Air We Breathe which can be seen here ( https://www.cbsnews.com/video/indoor-air-systems-public-health-60-minutes-video-2023-10-29/ ). 29/

The most important factor is how well a respirator fits on your face so there is minimal leakage around gaps as some respirators fit people very well and others very poorly. You can learn about my fit testing adventure where I found one mask leaked 70x more than another on my face ( https://pingthread.com/thread/1655331142990528514 ). 24/

Many people have anecdotally discovered and reported that Novavax doses had much lower side effects than when they received an mRNA shot. Multiple studies have now shown this to be the case as well. One preprint study (supported by Novavax) that compares the reactogenicity (frequency of side effects) of Novavax and mRNA vaccines ( https://medrxiv.org/content/10.1101/2023.05.31.23290594v1.full ). H/T: @michaelzlin 10/

They found a notable difference in the percentage of reported side effect symptoms with Novavax being lower in each category:
* 30.8% lower muscle pain
* 30.4% lower injection site pain
* 25.7% lower fatigue
* 25.4% lower injection site tenderness
* 24.9% lower malaise
* 22.4% lower swelling
* 18.3% lower headache
* 17.5% lower joint pain
* 13% lower redness
* 12% lower fever
* 3.5% lower nausea/vomiting

11/

What about people who had mRNA doses previously but want to consider Novavax?

There have been several studies now that found mixing the two, getting mRNA and then Novavax actually gave better results than just mRNA on its own. 12/

ASHRAE Standard 241, Control of Infectious Aerosols ( https://www.ashrae.org/technical-resources/bookstore/ashrae-standard-241-control-of-infectious-aerosols ) was released in July 2023 so this should now be adopted and required by governments in air quality standards for buildings like they already require clean drinking water standards for these same buildings. 19/

One study found that getting Novavax as a booster after mRNA "may enhance the persistence and durability of vaccine-mediated immunity compared to mRNA options" with slower decay rate compared to an mRNA booster dose and less side effects than mRNA boosters ( https://www.tandfonline.com/doi/full/10.1080/14760584.2023.2232020 ). H/T: @daniel_e_park 13/

It is important to have good indoor air quality, not just from viruses but also for cognitive function and from other air pollutants (like wildfire smoke) which have been linked to various health problems ( https://mstdn.science/@jeffgilchrist/109580638330581137 ). 20/

A randomized controlled trial found that getting a Novavax dose after Pfizer mRNA elicited the highest humoral and peak cellular immune responses ( https://www.journalofinfection.com/article/S0163-4453(23)00330-4/fulltext ). H/T: @michaelzlin 14/