The vaccine hesitant includes a range of people ranging from people fearful of getting a jab, those fearful of the consequences of getting a jab, to anti-vaxxers. ‘Herd immunity’, also known as ‘population immunity’, is the indirect protection from an infectious disease that happens when a population is immune either through vaccination or immunity developed…

# Search Results for: windup

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

We consider how much greater Ro is than Re. We look at the following table: For definitions see: Welcome In New Zealand both r = SQRT(2) and r = 1.429 provide good estimates for the total number of cases from 21 to 25 August 2021. See: COVID Odyssey: Winter Warning NZ 15 ~ Delta variant…

## COVID Odyssey: Worldwide Winter Windup 8 ~ Ro ~ Estimating Re & Ro by 3 straight lines

We have estimated Re and Ro for COVID-19 using the linear equation y = 17r – 18, where r is a daily growth rate of infections (estimated over the next 5 days). We now add in two extra lines to complete the approximations. The three lines are: y = 17r – 18 …

## COVID Odyssey: Worldwide Winter Windup 7 ~ Ro ~ Estimating Ro by a straight line

We estimate Re and Ro for COVID-19 using the linear equation y = 17r – 18, where r is a daily growth rate of infections (estimated over the next 5 days). i.e. We use the value calculated for y in the equation as an estimate for Re and Ro. Update: See: COVID Odyssey: Worldwide Winter…

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

We have already estimated Ro for the original COVID-19 Outbreak in 2020 and for the Delta variant. We have estimated Ro between 5 and 8 for the original COVID-19 Outbreak in 2020. We have estimated Ro between 9 and 12.7 for the original Delta COVID-19 Outbreak. We now estimate Ro for the 2020 Alpha variant. …

## COVID Odyssey: Worldwide Winter Windup 5 ~ Revised estimates for Re worldwide

We revise our estimates for Ro worldwide. Previously we had the ranking below (see r1 and Re1 columns) for the 2020 outbreak: The above was calculated using: Note that n = 10 days and r[d] is a daily rate of increase (growth factor) calculated over the next 5 days starting on day d for each…

## COVID Odyssey: Winter Windup 16 ~ Methods used to estimate Ro

Originally posted on COVID Odyssey by Alan Grace: My vir[tu]al COVID-19 journey:

In this post we shall look at ways experts analyse the spread of COVID-19. My own mathematical techniques are simple but have produced some surprising results. Analysis can quite often involve solving systems of differential equations (see below). How Ro is…

## COVID Odyssey: Winter Windup 15 ~ Executive summary ~ Our formula for Ro

Update for New Zealand Delta variant data and results see: COVID Odyssey: Winter Warning NZ 6 ~ Estimating the number of 2021 Cases ~ A simpler formula COVID Odyssey: Winter Warning NZ 2 ~ Delta variant ~ Lockdown 4 appears to be working For COVID-19 in the original 2020 outbreak, we have estimated Ro to…

## COVID Odyssey: Winter Windup 14 ~ COVID-19 ~ Simulations to develop our formula for Ro

We have used simulations to develop our formula for Ro which is based on the daily rate of increase, r, for cases. For simulations using r = 1.4 and r = SQRT(2), for each simulation we generate 40 outbreaks using Excel and calculate statistics. Sample runs are included in this post. Our formula for Ro…

## COVID Odyssey: Worldwide Winter Windup 4 ~ Is Ro 6 to 7.8 in early 2020?

For COVID-19 in early 2020, we have estimated Ro to be in the range 6 to 7.8. For the Delta variant we have estimated Ro to be in the range 9 to 12.7. Update. See: COVID Odyssey: Worldwide Winter Windup 5 ~ Revised estimates for Re worldwide We consider widening our range estimate for COVID-19…

## COVID Odyssey: Winter Windup 13 ~ Is the COVID-19 Delta variant as infectious as measles?

Experts think the COVID-19 Delta variant is much more contagious than the flu and chickenpox, and on par with the measles. See: https://www.healthline.com/health-news/cdc-says-delta-variant-as-infectious-as-chickenpox-what-to-know-now We have found that Ro for the Delta variant is between 9 and 12.7. See: COVID Odyssey: Winter Windup 9 ~ COVID- 19 Delta Variant 2021 ~ Is Ro in the range…

## COVID Odyssey: Worldwide Winter Windup 3 ~ COVID-19 in 2020 vs 2021 ~ Cases per million people

We look at cases per million people for the 31 countries with over one million cases on 6 August 2021 and compare the results estimated for the daily rate of increase, r, estimated a year earlier on 6 August 2020. We have looked at the spread of COVID-19 throughout the world early in 2020. We…

## COVID Odyssey: Worldwide Winter Windup 2~ Be afraid, be very afraid of the Lambda variant

Be afraid, be very afraid of the Lambda variant. Strong likelihood of more dangerous COVID-19 variants – WHO. The eighth meeting of the Emergency Committee convened by the WHO Director-General under the International Health Regulations (2005) (IHR) regarding the coronavirus disease (COVID-19) took place on Wednesday, 14 July 2021 from 11:30 to 16:00 Geneva time…

## COVID Odyssey: Worldwide Winter Windup ~ COVID-19 in 2020 vs 2021 ~ How many people may one person infect in your country?

We look again at the spread of COVID-19 throughout the world early in 2020. We look at case numbers up to 6 August 2020. As expected estimates for Re#2 (last column in the first table, calculated using our formula for Ro below), and hence Ro occurred very early in an outbreak in each country. Ro…

## COVID Odyssey: Winter Windup 12 ~ Conclusion~ Ro = 6 to 7.8 in early 2020?

We revisit data for the spread of COVID-19 in early 2020. We see in China that a daily increase close to r~ 1.5 fits the case data well from 23 Jan to 28 January 2020. We have seen in New Zealand that a daily increase close to r~ 1.4 fits the case data well from…

## COVID Odyssey: Winter Windup 11 ~ COVID-19 ~ Daily decline in infectivity

We have assumed that case numbers increase at a daily rate of r and infectivity decreases daily at a rate of 1/r. This simplifies the formula. However it is possible that infectivity decreases daily at a different rate. Below is a graph showing various rates: Below is data for the graph. Note: values have been…

## COVID Odyssey: Winter Windup 10 ~ COVID-19 Delta variant ~ Conclusions 2021

The Delta variant of COVID-19 appears to be twice as infectious as the original 2020 outbreak. We have found that Ro for the Delta variant is between 9 and 12.7. Ro is the average number of people once person may infect over a period of n = 10 days when there is no quarantine or…

## COVID Odyssey: Winter Windup 9 ~ COVID- 19 Delta Variant 2021 ~ Is Ro in the range 9 to 12.7?

The Delta variant of COVID-19 appears to be twice as infectious as the original 2020 outbreak. for the 2020 outbreak we estimated Ro = 6. In previous posts we simulated outbreaks using a value for Ro around 12.7 (actually Ro = SQRT(3)). In this post we consider also Ro = 9 (halfway between 6 and…

## COVID Odyssey: Winter Windup 8 ~ COVID- 19 Delta Variant 2021 ~ Graphs

We look at graphs of the number of people that may be infected by one person having the Delta variant of COVID-19. The graphs are produced from our simulations for 1778 cases for Day 12 starting with 10 cases on Day 1 and using a daily increase of r = SQRT(3) with an infectious period…

## COVID Odyssey: Winter Windup 7 ~ COVID-19 Delta Variant 2021 ~ Simulations

In the previous post we saw that for the Delta variant there could be a daily increase in the number of cases of r = SQRT(3). For background see: COVID Odyssey: Winter Windup 6 ~ COVID-19 Delta Variant 2021 ~ Does Ro = 12? This would give rise to the table below: We see from…

## COVID Odyssey: Winter Windup 6 ~ COVID-19 Delta Variant 2021 ~ Does Ro = 12?

We look at the how many people one person with the Delta variant of COVID-19 may infect on average in 2021. By definition we let: r denote the effective Reproduction rate of COVID-19 for one day 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…

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

In this post we conclude that we need to go back to our original results for estimating Ro. By definition we let: r denote the effective Reproduction rate of COVID-19 for one day 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) a case be defined…

## COVID Odyssey: Winter Windup 4 ~ The formula for calculating Ro

In this post we develop the formula we have used for calculating Ro, the number of people one person may infect on average over a 10-day symptomatic period (n = 10) given a daily increase r in the number of cases and a daily decrease of 1/r in infectivity. Note: The formula in this post…

## COVID Odyssey: Winter Windup 3 ~ Carpe diem 2020 ~ Estimating Ro by simulations

In early 2020 we calculated that there was a daily increase in cases of r = 1.4 and we assumed infectivity decreased by 1/r each day over n = 10 days. We created simulations to estimate Ro, the number of people a person with COVID-19 was likely to infect on average. How do we choose…

## COVID Odyssey: Winter Windup 2 ~ In early 2020 can one person infect 4 or 6 others on average?

Ro is the number of people that on average one person with COVID-19 may infect. Note: The formula in this post has been updated. See: COVID Odyssey: Winter Windup 5 ~ Conclusions for 2020 ~ Back to the past: Re = 5.8 and Ro = 6 Early in 2020 we arrived at the following table…

## COVID Odyssey: Winter Windup ~ 2020 simulations revisited

We revisit the simulations undertaken in early 2020 to estimate the number of people one person with COVID-19 may infect on average over an n-day infectious period. We developed a formula calculating the numbers Ro and Re (with and without isolation respectively) given a daily rate (r) of increase in cases. We also produced a…

## COVID Odyssey: Winter Warning NZ 15 ~ Delta variant outbreak 2021 ~ Estimating Ro and Re

We estimate under the current Lockdown Level 4 in Auckland one person may infect 6 to 6.3 other people in New Zealand in the current Delta variant outbreak of COVID-19. Without lockdown we have estimated one person with the Delta variant of COVID-19 may infect 9 to 12.75 other people. See: COVID Odyssey: Worldwide Winter…

## COVID Odyssey: Winter Warning NZ 11 ~ Delta variant ~ Will NZ Cases exceed last year?

The total number of cases in this outbreak in New Zealand is likely to exceed the the total in the outbreak early in 2020 if the midpoint is in September. Update. See: COVID Odyssey: Winter Warning NZ 12 ~ Estimating the number of 2021 Cases ~ What will the total be? Yesterday the number of…

## COVID Odyssey: Winter Warning NZ 10 ~ Delta variant ~ Analysis

We analyse the 2021 outbreak in New Zealand. We hope that the midpoint has been reached. By definition we let: r denote the effective Reproduction rate of COVID-19 for one day 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) a case be defined as a…

## COVID Odyssey: Winter Warning NZ 6 ~ Estimating the number of 2021 Cases ~ A simpler formula

We have developed a simpler formula for estimating the number of cases in New Zealand for the current COVID-19 Delta variant outbreak.. Our formula is: C = r^d where r = 1.429 and d = the number of days since 10 August 2021. Here is the PDF version: NZCases2021r The effective reproduction rate (Re) is…

## COVID Odyssey: Winter Warning NZ 4 ~ Delta variant 2021 ~ Case numbers appear exponential Dr Bloomfield

New Zealand COVID-19 (Delta variant) Case numbers are exponential. From today’s NZ Herald (26 August page A4): Case numbers can be estimated using the formula C = 1.16 x SQRT(2)^d where ^ means ‘to the power of’ and d is the number of days from 10 August 2021. We estimate the total number of cases…

## COVID Odyssey: Winter Warning NZ 3 ~ Estimating the number of 2020 Cases ~ Where is the midpoint?

We revisit the spread of COVID-19 in New Zealand in early 2020. The object is to apply the exercise below to the current 2021 Delta outbreak in New Zealand. To estimate the total number of cases, we first have to consider when we may have reached the midpoint. Even if the midpoint is assessed accurately,…

## COVID Odyssey: Winter Warning NZ 2 ~ Delta variant ~ Lockdown 4 appears to be working

Lockdown Level 4 appears now to be starting to bring down the daily rate of increase (r) of case numbers of COVID-19 in New Zealand. Update: See: COVID Odyssey: Winter Warning NZ 6 ~ Estimating the number of 2021 Cases ~ A simpler formula ee the last column in the table below where values for…

## COVID Odyssey: Winter Warning NZ ~ Delta variant ~ May one person infect 12 others?

Based on NZ current case numbers for the Delta variant, we estimate on average one person may infect at least 12 others (Ro > 12) without quarantine or isolation. Case numbers may close to triple over a two-day period (1.7 x 1.7 = 2.89). For the Delta variant worldwide, we have estimated Ro to be…

## COVID Odyssey: Get your jabs

Get your jabs There are those that would extinguish The light that God has made And interrupt our journey And all the plans we laid There are those that would take our spirit And make us feel such pain To wash away the progress And years of hopes and gain We must all stand united…

## COVID Odyssey: Winter warning ~ Summary 2020 revisited ~ Daily cases and how many people one person may infect on average?

In 2020, We found that in New Zealand given a a 10-day infectious period, and a daily increase in COVID-19 infections of r = 1.4, one person with COVID-19 may infect on average 4.14 other people and for a 15-day infectious period, one infected person may infect around 6 other people. We extend our previous…

## COVID Odyssey: Vir[tu]al World Tour ~ How many people can one person infect in your country?

Please read Updates:https://aaamazingphoenix.wordpress.com/?s=windupCOVID Odyssey Ro update: Occam’s Razor~ A close shave: In NZ is Ro ~ 3, 4, or 6? What are Ro values worldwide?COVIDWorldAvNewRanked4COVIDWorldAvNewAlpha4COVIDWorldAvNewRanked4rCOVIDWorldAvNewAlpha4r We estimate Ro (see below) by applying the analysis undertaken in New Zealand to the rest of the world. Note that data for the analysis below is for confirmed cases…

## COVID Odyssey by Alan Grace: New Year Fare ~ Contents

COVID Odyssey Contents (see below for Contents) You can come back to this page from the HOME/ CONTENTS menu from: COVID Odyssey by Alan Grace: New Year Fare ~ Contents (Hover over the HOME/ CONTENTS menu at the top of the screen) COVID Odyssey by Alan Grace Alan Grace’s journey exploring COVID-19. Findings (See #6 below)….

## COVID Odyssey. COVID-19 NZ: [In NZ Ro ~ 3, 4, or 6? See Update] Re~5.8 & Ro~6?

COVID Odyssey COVID-19 in New Zealand Findings Alan Neil Grace [Updates will be available soon only in an ebook; Contact Alan Grace for details about the ebook] Introduction [Ro ~ 3, 4 or 6? See Update] Re ~ 5.8 and Ro ~ 6? Please read update (accept original results): Search Results for “windup” – COVID…

## Welcome

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…