“Has Omicron peaked?” seems to be the number one news item.
If you look at overall case counts, it looks like the UK has peaked and is declining, following the pattern seen earlier in South Africa. In Canada and the U.S. people are hoping that the same pattern will follow, and soon.
Because of the shortage of Covid tests, many people who get Omicron do not get tested and so the number of reported cases is much lower than the true number of people with Covid. Here is the forecast for Canada that takes the unreported cases into account.
The January 4 blog predicted that Omicron would peak towards the end of January at about 125,000 cases and return to pre-Omicron levels at the end of February. The Canada forecast here is similar but with a sharper and more rapid peak and decline by the end of January.
If this forecast holds true, it does not mean the crisis will be over by the end of January. Hospitalizations and deaths lag the case counts by a few weeks. There has just been a sharp increase in ICU cases and deaths.
There was another informative email from Dr. Andrew Morris this week. If you haven’t read it, here are some of the key points.
– in previous waves we have seen “false peaks” where it looked like a peak was achieved, when really it was a temporary decline that preceded another increase in cases.
-people in Canada will unnecessarily suffer more from Covid because of a shortage of therapeutic agents (medicines that have been approved for treating people who are sick with Covid). We suffer from insufficient production, insufficient procurement, poor coordination, delayed approvals and mismanagement by some provincial officials.
– one reason Ontario hospitals are struggling is because it has very few hospital beds per capita.
Masks
Because Omicron is so much more transmissible than previous variants, it is highly recommended that people use an N95 or KN95 mask. These masks are almost twice as effective as the more widely used surgical masks or cloth masks.
However, a lot of K/N95 masks that are being sold, even from reputable sources, do not meet the standard of filtering 95% of particles. The following report shows the test results of many masks being sold.
The K/N95 masks generally make it harder to breathe and may be uncomfortable if you need to wear it for a long period of time. I initially used a N95 mask that had two ties that go over the head. I found this very awkward because it was difficult to undo enough of the mask to take a drink of water or wipe your nose. I switched to a KN95 mask that has ear loops which I found to be more flexible and also more comfortable.
Here is a good report on How to find the right Covid mask (and avoid counterfeits).
If you find that you just can’t wear a K/N95, you can improve the fit of a surgical mask by folding it according to these instructions.
How to Knot and Tuck Your Mask to Improve Fit
Is Covid becoming Endemic?
More and more people are talking about herd immunity or the pandemic becoming endemic after the Omicron wave. This is all conjecture. I haven’t seen any science. Here is a way to estimate this.
1. Using the basic epidemiological model with an estimate of R0 = 10.0 for Omicron, herd immunity is reached when immunity of the population is at least 90%.
2. Canada’s vaccination rate is currently 78% of the whole population. Not many of the remaining unvaccinated people are likely to get vaccinated. After numerous campaigns, vaccine mandates and various other incentives, most of the unvaccinated are pretty firm in their position.
Tracking the spread of the coronavirus in Canada
3. The number of people who have been infected with Covid and received natural immunity is currently about 3 million. Adding in an estimate for the uncounted cases during the Omicron wave will increase this to about 5 million, or 13% of Canada’s population.
4. The total immunity in Canada after the Omicron wave will be 78% + 13% = 91%. This is on the border for herd immunity.
However, because of increasing breakthrough infections in people who have been vaccinated, the effective level of immunity will be less than 91%.
It remains to be seen if Omicron is the last wave, but even if it is, many people will continue to get sick and die from Covid. This is an endemic state, similar to influenza. In 2018-2019, before the coronavirus pandemic, there were 10,000 cases of flu per week in Canada during the winter peak.
Nice review Ernie!