Welcome. My name is Alan Grace. I live in Titirangi (Auckland, New Zealand).

Welcome to My COVID Odyssey.

By definition we let:

  • r denote the effective Reproduction rate of COVID-19 for one day; r is the growth in the number of cases. We usually calculate r (for one day) using the rise in cases over the next 5 days.
  • Ro (R0; R-Zero; R-Nought) denote the Reproduction number for COVID-19 without any quarantine or isolation
  • Re denote the effective Reproduction number for COVID-19
    (Re assumes isolation/quarantine is happening)
  • case be defined as a person diagnosed as having COVID-19

Note that Ro and Re are numbers (not rates), the number of people one person with COVID-19 may infect on average without quarantine or isolation (Ro) and with quarantine or isolation (Re). Ro and Re both use this formula:


where n = 10 infectious days.

We assume that infectivity reduces by a factor of 1/r each day.

Below please find values for r (daily growth) and corresponding values for Re:


We also have this table:


This PDF may be easier to read:



COVID Odyssey: Worldwide Winter Windup 9 ~ Ro > Re ~ How much greater is Ro?

COVID Odyssey: Winter Windup 5 ~ Conclusions for NZ in 2020 ~ Back to the past: Re = 5.8 and Ro = 6

COVID Odyssey: Worldwide Winter Windup 6 ~ Ro ~ Estimates for the Alpha and Delta variants

Please obtain prior written permission from the author (Contact me) before publishing or copying anything from this site on any another site or anywhere else (Reblogs OK).

Please read the Disclaimer.

Please note: any ads are beyond my control 😦

Rather than take up screen real estate at the top of my Home page, I have put my Welcome page on this separate page so that you don’t need to scroll down past it all the time (this is one of my pet hates; having to scroll down when there are large images at the top of a page).

I like Escher’s work. Surreal. See more here.

View more in Google

View some more in Google

Go back to my home page.

My posts often change. I cannot resist tinkering and updating.
My posts (especially poems) seldom stay static. Come back to see the changes.

You may like to view: My ‘First’ post (formerly Alan Grace: Header Post)

Enjoy my Blog.

Alan Grace


Wordplay … Poetry in Progress.

The AAAmazing Phoenix



11 Comments Add yours

  1. Sorry! My schedule is nuts today so perhaps this is why the prompt rules are not clicking with me. Good luck!


    1. AlanGraceNZ says:

      To share your own post, just put the following line anywhere in your post:
      (Click on the same link to view posts)

      Liked by 1 person

    2. AlanGraceNZ says:

      You’re welcome Martha. The easiest think to do is just put the link into one of your existing posts and watch the magic happen 😉


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