Five safety tips for the holidays

How to reduce your risk of an Omicron or respiratory virus infection when gathering with family and friends.

credit: CDC

First, know the real facts

Omicron is still infecting over 100,000 Canadians a day according to the Institute of Health Metrics and Evaluation.

Canada has already set a record for covid deaths this year.

Scientists estimate that about half of those infected do not know they are infectious.

Science tells us that Omicron is airborne.

The science also tells us you can get reinfected.

Vaccines are important for adults and children in reducing infection and hospitalization risk but they do not eliminate it. If they did, Omicron infections, hospitalizations, and deaths would not be setting new records in Canada.

Hospitals and doctors are also warning us about the surge of child hospitalizations.

1. Get your covid and flu shots

Year-end holidays have historically been a time of high infection spread with peaks in hospitalizations and deaths following in January. Encourage your friends and family to get their covid and flu shots. They are safe and they work to help keep everyone safe.

Vaccines for Omicron reduce your risk of infection and severe outcomes. To be most effective, you need to keep them current and to recognize that they are not a magic shield. The effectiveness of vaccines is not 100%, they may be approximately 60% protective against symptomatic infection (this is true for Flu shots as well), and vaccine shots will wane further over time against Omicron. Protection from previous infections will also wane. In most jurisdictions you are eligible for an updated Omicron booster between 3 and 6 months after your last shot or infection. At time of high risk, I do not encourage waiting the full 6 months but check with a medical professional to be sure.

Vaccines do work. In Ontario, the risk of covid hospitalization drops significantly for every age group with a booster shot compared to being unvaccinated:

2. Make RAT’s and symptom checks part of your plan

First of all, as a holiday host let people know that they need to take a covid rapid antigen test (RAT) before arrival. And if they have symptoms like coughing and sneezing, it’s best if they stay home this holiday season (sorry). If someone has driven a distance and has obvious symptoms at the front door hand them an N95 mask or equivalent, ask them to wash their hands often, and to keep the mask on and only unmask to eat and drink while keeping distance from other people.

On rapid tests: Yes, they do still work against Omicron variants but it’s important for guests and hosts to properly test before arrival and to recognize that it might be days after exposure before someone becomes infectious and tests positive on a RAT. Remember, RAT’s test for infectiousness, not if you clinically have covid and are not at an infectious level. Also keep in mind that RAT’s are just one of your layers of defence against Omicron. No one measure is perfect, so don’t rely on only one measure. Make RAT’s part of your holiday safety plan.

Credit Financial Post and Dr. Michael Mina et al

My second thread goes into more of the evidence and explanations.

Here’s a video demonstrating how to conduct a rapid test:

3. Ventilate to Celebrate

Most Omicron transmission is airborne and lingering aerosols can build up in a closed space and infect loved ones who aren’t even next to a family member. So you need to exchange more inside air with the outside. Keep your furnace fan on high, keep your bathroom and other fans going. Open some windows. I know it’s cold out but even a couple inches can make a big difference! Be crafty, tell everyone to wear an ugly sweater to your gathering (it will help keep them warm). If you have one, a CO2 monitor can tell you how well your room is ventilated. If it’s too high, up your ventilation. A portable fan can also help direct contaminated air out of the room. There’s more on ventilation, CO2 monitors and indoor air science in this thread.

This UK government video explains how ventilation can make your holiday gathering safer.

4. Filter out the virus particles - build a Corsi-Rosenthal box

Richard Corsi and Jim Rosenthal came up with a do-it-yourself room filter that is inexpensive and super-easy to build with a little duct tape, a few MERV filters, and a flat room fan. They work amazingly well in filtering out Omicron virus particles. CTV News tells the story. Here’s a video below explaining how to build one or you can go to this cleanaircrew.org link for instructions.

I have more in this thread on the science of filtration and DIY C-R boxes:

Bill Comeau 🇨🇦🇺🇦 @Billius27

🧵Indoor filtration: #CovidIsAirborne 1. When adequate ventilation cannot be achieved, HEPA filters offer a very good alternative. This recently published study provides clear evidence that HEPA filters can remove SARS-COV-2 from the air. #covid19 journals.asm.org/doi/10.1128/ms…

5. Spacing, Masking, and Hygiene

My last tip is for the host. While masking at a home gathering may be challenging given the current belief that Omicron risks are low and few are dying (untrue), you can still arrange spacing and utilize the four other tips. Consider arranging the dinner seating in an “Omicron smart” way. We know that many infections happen when people are unmasked and close to each other. You can space out the seats or have multiple tables or TV trays with chairs apart six feet. This demonstration by the Riken Center for Computational Science helps show how infectious particles spread at a table.

If family and friends are willing to mask when not eating because there is someone vulnerable at the gathering like an immunocompromised child or a grandparent, I’d recommend having N95 masks available to hand out. They are a major upgrade over cloth, as I explain in this article but even cloth masks will help much more than being unmasked near vulnerable loved ones.

It’s very difficult to find any evidence that you can catch Omicron by touching a surface. That’s because it is mostly an airborne virus. But I encourage the host to provide plenty of soap, hand towels, tissues, and encourage guests to wash their hands. That’s because flu, RSV, and many other respiratory viruses are very transmittable from surfaces and hands.

There are many reasons to play it smart this holiday season, including keeping our children out of hospital.

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Enjoy your holidays! 🎄🍾 🎁

Omicron is still here along with other seasonal viruses and still threatening to make us sick and burden our hospitals. But we can make Omicron and other respiratory viruses less welcome in our homes with this 5-step plan and reward ourselves with a festive and happy season. No one step is a magic shield but a multi-layered home plan can minimize our risk. Doing so can save our loved ones from illness or worse.

I wish you all the merriest and safest of holidays, whatever your faith or traditions!

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Who am I? I am a retired and independent Canadian statistician with a Master’s in Mathematics from the University of Waterloo. I have tracked and visualized covid-19 data and shared the emerging science since the beginning of the pandemic.