Coronavirus, Tracking Coronavirus, Cryptography, Value of Military Bases, Retirement Tool, Check your Retirement
Coronavirus
 Coronavirus (COVID – 19)
Test, Trace, Isolate and Treat  
This page was last updated on July 2, 2021. Refresh for the latest.
Next update will be on July 9, 2021.
Guide to COVID-19 Indicators V5.0 Guía de Indicadores de COVID-19 V4.5 US Forecast (Excel File) V2.0

Reproduction numbers, R, are epidemiological metrics used to estimate how many people a patient is likely to infect and, therefore, how fast an epidemic will spread or recede. R is not a biological constant for a pathogen, a rate over time, or a measure of disease severity.


In this web site, R is the Constant Daily Rate of Growth calculated over a period of 14 days. Download the paper “Guide to COVID-19 Indicators” for more information.

How is the US and Texas Doing?

The followings are the last five weeks of US Constant Daily Rate of Growth, (R), for Confirmed, Deaths, Recovered, and Active:

                    Limit =1                                            Limit = 1                                  Limit =1                                               Limit = 0

Jun 4:      R(Confirmed)   =1.0005           R(Deaths) = 1.0009          R(Recovered) = 1.0011             R(Active) = 0.9599

Jun 18:   R(Confirmed)   =1.0003           R(Deaths) = 1.0006          R(Recovered) = 1.0005             R(Active) = 0.9770

Jun 25:  R(Confirmed)   =1.0004           R(Deaths) = 1.0005          R(Recovered) = 1.0005             R(Active) = 0.9845

Jul 2:      R(Confirmed)    =1.0004           R(Deaths) = 1.0004          R(Recovered) = 1.0004             R(Active) = 0.9937

Week by week, the Constant Daily Rate of Growth of Confirmed, new cases, calculated over 14 days is above 1, but decreasing, which means that the epidemic is been controlled. In the last 28 days, R (Active) is now below 1, meaning that the number of Active cases is decreasing. On July 2, in the US, there were 21,069 daily new cases; previous week was 14,914. In Texas there were 1,878 daily new cases; previous week was 1,729. The highest daily new cases in the US was on January 6, 2021, 305,390 cases/day


Chart 1A

Doubling Time

 May 28, 2021  -  The number of Confirmed cases in the US will double to     34,444,920 in       900 days, November 14, 2023

Jun 18, 2021    -  The number of Confirmed cases in the US will double to     34,176,494 in    1,266 days, December    4, 2024

Jun 28, 2021    -  The number of Confirmed cases in the USA will double to  34,113,207 in    2,332 days, November 16, 2027

Jul 2, 2021         - The number of Confirmed cases in the USA will double to   34,595,550 in        824 days, October         3, 2023


Chart 1B

The number of days that it will take for a country to double the number of Confirmed cases is also an excellent indicator to determine if COVID-19 is receding or not. It is a good sign when the number of days to double increases; the epidemic is receding. If the number decreases, the epidemic is not receding.


Forecasting

For the forecasting calculations, the Constant Daily Rate of Growth, R, is multiplied by a factor m to reduce the differences between current and forecast values, kind of a smoothing spline. The new linear daily rate of growth r is equal to r = m * R. The m factors are calculated separately for Confirmed, Deaths, and Recovered values and therefore are different. 


If a country is controlling the epidemic, at some moment in time, the number of recovered and confirmed cases should be the same, no more new confirmed cases, and everyone recovered.


Chart 2 shows the forecast values of Confirmed, Deaths, Recovered, and Active. To forecast those values for the US and Texas, I use the Final Total Infected formulas developed by Dr. Fookfah Yap, an Associate Professor of Engineering at Nanyang Technological University, Singapore.  The Google Sheet he uses to estimate the COVID-19 reproduction number, doubling time, and final infection number for different countries can be viewed here. https://docs.google.com/spreadsheets/d/1rRwucxmdn5YqHVkelbEWaIuUdWauXyym39B8xr2aEHQ/edit?usp=sharing

The following is the link to his website, https://cv19.one/


Recovered is increasing faster than new confirmed cases, the gap is decreasing. It is an indication that US Forecast Recovered and Forecast Confirmed cases would be the same soon. These are good news.


See more information on how m is calculated at https://www.mmogollon.com/coronavirus-references


The forecasting coefficients of determination,  R², are shown in the charts below.


The forecast calculations use data from the University of Virginia, "COVID-19 Surveillance Dashboard," that uses a special algorithm to calculate Recovered values based on Confirmed values. https://nssac.bii.virginia.edu/covid-19/dashboard/

 

Chart 2

Chart 3

Vaccine Efficacy

Immunity is not instantaneous, it takes time to develop. Body immunity changes are not a step function, they change gradually. A person's vaccine efficacy increases according to the number of days after the first and second doses.

 

I decided to create a chart showing how Pfizer and Moderna immune efficacy change with time. The information may help you to understand the level of immunity you have while continuing to follow recommended safe practices.


Determine your immunity level by looking at the corresponding number of days after vaccination.


Based on a Pfizer article published on December 10, 2020, at NEJM.org, the first dose vaccination efficacy is 52.4% after 21 days. Seven days after the second dose, the efficacy is 90.4%.  Twenty-one days after the second dose, the efficacy is 94.8% and remains at that value from then on.


Based on a Moderna article published on December 17, 2020, by the FDA, fourteen days after the first dose, the vaccine efficacy is 50.8%. Fourteen days after the first dose and before the second dose, the efficacy is 92.1%. Fourteen days after the second dose, the efficacy is 94.1% and twenty-eight days after second dose is 95.6% and it remains at that value from then on.


Sinovac’s 51% efficacy only just exceeds the WHO’s 50% efficacy threshold for Covid-19 vaccines. More than 350 doctors and medical professionals have contracted Covid-19 in Indonesia despite the majority of healthcare workers having been immunized with Sinovac,

https://www.forbes.com/sites/roberthart/2021/06/17/chinas-sinovac-vaccine-under-scrutiny-as-covid-soars-in-highly-vaccinated-countries/?sh=175afe311444


Note: CDC website and Texas Websites show the number of people that have been vaccinated and the number of people who have received the second vaccine.

US and Texas Herd Immunity

Chart 3 shows US and Texas Herd Immunity forecast using a Ro = 3.27. The blue line is the percentage of the population needed for herd immunization over time. The grey line is the number of immune people (Recovered + Vaccinated * Vaccine Efficacy), as more and more people get vaccinated, and as the number of recovered people increases. The yellow line is the immune population percentage over time. As time passes, the percentage of the immune population increases, and the requirement and time t for herd immunity decreases. A country achieves herd immunization when Re(t) ≤ 1, not in the graph, when the percentage needed for herd immunization is zero or when the yellow line value equals the blue line's initial value. For the US, that date is September 3, 2021; in Texas, the vaccinated population is 44% and growing very slowly. There is not a forecast date for Texas herd immunity for the next three months.


Assumptions:

  1. The number of Recovered people will continue growing at the same daily rate of the last 14 days, 0.052% for the US
  2. The number of vaccinations will continue increasing at the same daily rate as in the last fourteen days, 0.267% for the US
  3. The number of first time vaccinations per day in the U.S. will top at 600,000. As of July 2, 2021, it was at  463,621 per day.

See more information on how Herd Immunity is calculated at https://www.mmogollon.com/coronavirus-references


Chart 4
Control measurements slow down the community's viral spread, and epidemiologists calculate the additional percentage reduction (μ). Data-driven compartmental models can make accurate short-term forecasts for exploring hypothetical control measurements. For example, according to German researchers, masks can reduce the growth rate of coronavirus infections by 40% (μ).

Chart 4 shows a simulation of how Active cases increase or decrease.

Note that when each of the curves starts decreasing, that is the day when the daily increase of Active cases is negative. In other words, it is the day when the US has flattened the epidemic. The situation in the US is controlled, but people should be wearing a mask and be getting vaccinated. 

The US population should continue taking measures to reduce the growing number of Confirmed cases, i.e., wear a mask when you are outside.

The number of daily new cases has been reducing week by week since April 15. 

As you can see in the chart below, the recent decline since April 15 is much gentler than the declines during most of January and February.  The reasons aren’t clear, but it’s another sign that the pandemic is ending in the near future. The average decrease between the weeks of May 28 and June 18, was 3%. In the last couple of weeks, the number of daily cases has been increasing.

Chart 4C - Nightingale Diagram of New Daily Coronavirus in the US per Day and Month


The Nightingale Diagram allows seeing, in an easy way, what is happening month by month. For example, during March and April, COVID 19 was ramping in the US, and during several days in January 2021, the number of new cases per day was 300,000.  April and May were much better than January. 


US and Texas COVID-19 Factors
When fewer people get infected per day, some people say that the curve is flattening. However, in the US, on several occasions, the number of daily new cases started to decrease, but the number of still infected people was still increasing. A better way to get a view of what is happening is to chart the COVID-19 indicators used in this web site. A country has flattened the curve when:
  • The R (Active), the green line, crossed the value of 1 and remained below 1.
  • The K1-Factor, the red line, is increasing to its limit of 1.
  • The K2-Factor, the blue line, is decreasing to its limit of 0.
Figure 1 shows three of the ratios described in the paper Guide to COVID-19 Indicators for the US. Around March 5, all the indicators were showing that the US was controlling the epidemic. After March 5, there was a surge, and only until the week of April 23, the US appeared to get control of the epidemic.

In Texas, see Figure 2, the curves in the chart are also moving in the correct receding directions. 
Figure 1 - US Factors
Figure 2 - Texas Factors
US States & Counties and Countries R Values Calculations 
Tables 1 through 4 show the COVID-19 ratios described in the paper Guide to COVID Ratios by Manuel Mogollón.  
All R values are essential because they tell us the average percentage increase or decrease of new deaths, recovered, or active cases for the previous 14 days. The threshold here is R = 1; if R > 1, then values are increasing, not good; if R <= 1, values decrease or remain the same, good. Values with R<=1 are highlighted in green. However, it is better to follow R (Active) because the Active value (people who are still infected) is not cumulative, so a good reference is when R (active is less than 1.
Normalized R Values for Selected States, Counties, and Countries
Charts 5, 6, 7, and 8 show the R Values for a group of States, TX Counties and Countries. Use R = 1 as a reference, if R >1, then values are increasing, no good; if R < 1,then values are decreasing, good. 
Chart 5 – State R Values 
Chart 5 shows the top fifteen states with the highest number of confirmed cases. The bar values indicate the rate of decrease in Active cases in the last 14 days. In California, Texas, and Georgia, Active cases are decreasing by around 1% (1-0.99)*100, 1.4%, and 1.3% daily. In Florida and in Arizona Active cases are increasing by 2.7% and 1%.

Chart 6 State R Values by New Cases

Chart 6 shows the top fifteen states with the highest rate of increase in new cases. The blue bar values indicate the rate of increase in new cases in the last 14 days.

 Chart 7 Texas County R Values
Chart 7 shows the top fifteen Texas Counties with the highest number of confirmed cases. The bar values indicate the rate of increase in Active cases in the last 14 days. With the exception of Bexar, All counties are controlling the COVID-19 epidemic.  
Chart 8 – Country R Values
Chart 8 shows the top fifteen countries with the highest number of confirmed cases. The figures indicate the rate of increase in Active cases in the last 14 days.
 Chart 9 – Summary of US by State
05/28/2021
May 28, US Totals: Confirmed: 33,240,637     Deaths: 593,480          Recovered (Est.): 32,163,492        Active (still infected):         483,665
Jun 4, US Totals:     Confirmed: 33,337,129      Deaths: 596,382          Recovered (Est.): 32,400,498        Active (still infected):         340,249
Jun 18, US Totals:  Confirmed: 33,481,347      Deaths: 601,113          Recovered (Est.): 32,634,690        Active (still infected):          245,544
Jun 28, US Totals:  Confirmed: 33,592,074      Deaths: 603,665          Recovered (Est.): 32,776,384        Active (still infected):           212,025

In less than one month, the number of current cases went up by only 0.97%; the previous week was 0.72%, and before, it was 2.06%. 
New cases are increasing at a lower rate.
The number to look at is Active (still infected); when the number is week-by-week lower, the US is controlling the pandemic. 
For the last two weeks, Active (Still infected) grew in six states. See red bars below.

US State data is from to the University of Virginia COVID-19 Surveillance Dashboard

https://nssac.bii.virginia.edu/covid-19/dashboard


 Chart 10 – Summary of Top Confirmed Countries 
05/28/202 1
 When will the US Active values be like when they were in 2020?  
We can use decreasing Active values and compare them to one, two, or three months from last year. The first problem is determining at what ratio the US Active values are decreasing; we will select the rates for the previous 14 days.

There is a moment when the tide turns around in each country, and Active numbers stop increasing and start decreasing. It is possible to use those dates and values to calculate the rate at which the number of still infected people decreases.

Active Cases has been decreasing, and it reached last year following milestones:
Date                                                    Active Cases                             Date Reached
December 1, 2020                         2,683,396                           February 5, 2021
November 1, 2020                        1,183,380                            March 10, 2021
October 1, 2020                                  793,902                           April 17, 2021 (Forecast)
   
Notice that the US Current Active (Still Sick) people, blue line, is decreasing. The US is controlling the pandemic. If the pandemic continues declining as in the last two weeks, it will take only 13 days, June 18, to go back to where we were on April 1st, 2020.

At the worst point, the number of Active Cases in the US was 4,099,450 on January 15, 2021.

Share by: