February 20, 2021

We are Reaching Half-A-Million COVID 19 Deaths in the United States.

By the end of Monday 22nd February 2021, we will pass through and above 500,000 deaths from COVID19 in the United States. I calculate and plot the doubling time in days averaged over a moving 7-day period. Doubling time, based on the previous seven days average, as of the end of 2020 had dropped below100 days. The doubling time for US deaths from COVID19 is increasing again early in 2021, as seen in the current graph below.

February 11, 2021

What are the Special Syringes for More Vaccine Doses?

You have heard about the idea of getting an extra dose out of a vaccine vial? It is on the news regularly. The Pfizer vaccine comes in a volume to get 5 doses, but there is some extra volume provided to allow for getting those 5 doses. Then, if you have a special syringe you could get a sixth dose.

How? 

A regular syringe will empty a few hundred microliters of liquid when the plunger is pushed. When the plunger reaches the end of the regular syringe there will still be some liquid in the small channel between the plunger and the start of the fitted needle and inside the needle itself. This is called dead space volume and it can be 70 to 90 microliters. After five uses that adds up to about 400 microliters, almost half of a 1 milliliter (1 cc)  syringe, or at least one extra sixth dose.

There are, however, syringes like special insulin syringes that come with an attached needle and have a very thin, and very short channel between the plunger and the needle. Some have a thin plunger extension that also pushes into the thin channel. As a result of this, these syringes have a very low dead space volume, from 2 to 5 microliters. So, if you have these low dead space syringes, you do not lose that 400 microliters after five injections, so several hundred microliters remain in the vial to give you one more shot. The six shooter!

Ken Mitton

February 6, 2021

New Covid19 Variants Can Infect Those Who Had Covid19 Before. Vaccination Protects Better.

It looks like the newly adapting Covid19 variants can reinfect persons who had the illness before. There is emerging evidence from the UK that this is a new concern. However, there is also emerging evidence that vaccinated persons are more resistant to illness and infection from the same new variants. The South African variant is one example of the newly evolving Covid19 strains. 

Some preliminary testing has been done using patient blood serum from persons vaccinated with various versions of the vaccines now in use. Here is what we know as of early February 2021.

  • The Pfizer two-dose vaccine (RNA type) seems to generate serum antibodies that react and bind well to the spike protein of the South African variant.  The paper reporting this is not yet peer-reviewed in a journal but it is pre-print public here: https://www.biorxiv.org/content/10.1101/2021.01.07.425740v1
  • Other vaccines in the process of approval review in the UK seem to offer some reactivity to protect against the new South African variant too, as reported in this BBC news post: https://www.bbc.com/news/uk-55850352
  • Oxford-AstraZeneca's vaccine offers limited protection against the new variant but the company is also now developing a second version of the vaccine to match the amino acid changes in some of the new variants that are evolving around the world.

So, for those persons who had Covid19, their immunity after a real infection may not be a justification for skipping vaccination. I am signed up and eagerly awaiting my turn. I will gladly get vaccinated and I suggest you get it too even if you have recovered from a covid19 infection. 

Ken Mitton
The Science Rant

November 11, 2020

November 2020: The Rule of 70 and Why Your Hospitals are Feeling the COVID Tsunami Second Wave

Math helps us understand disease spread in populations. A historical view of the rise in cases of COVID19 as the first wave hit in March 2020. The apparent and surprising rise in cases after a long period of just a few cases is typical of the exponential nature of pandemic disease spread in populations. US data seems to have an instant-looking start because there was no significant amount of patient testing, then testing is being increased. Back in March, the actual cases in a population spreading COVID19 were increasing at 12% a day, which the Rule of 70 tells us is a doubling every 6 days. (Graph by KPMitton from CSSEGIS COVID19 data )

1/11/2020 UPDATE: 

This is an update of a posting I wrote back in March 2020 in the first wave of COVID19 just rising mostly in states where COVID19 first arrived. We are in danger again of having local hot spot states now like North Dakota, South Dakota, Texas, where the percent daily increases in cases exceed 5% per day. Early in 2020, we were up to a national average of 12% per day in the first wave. Rates one month ago had dropped well below 1% but now the average US daily increase in cases over last week had risen to 1.5 % per day, but that is the average of all 50 states. In hot states now we are having community locations with over 5% daily increases, and the experience in March will now happen again in November and December 2020. When you have a constant percent daily increase in case number, this percentage factor leads to an acceleration in numbers that can easily and suddenly fill a hospital. Here is the reason, the simple math behind it all. The Rule of 70.

October 23, 2020

In search of reliable mobile fast tests for COVID-19 Antibodies.

 

While all research labs were shut down for a few months, late March to mid-June 2020, for all but COVID19 related research, I turned my biochemical skills to a project to help evaluate one version of a serum COVID-19 antibody test that can use a single droplet (10 microliters) of blood from a finger-poke and which gives a reliable result in 15 minutes. Also without using any powered equipment. Cheap, mobile reliable tests like this can be used in almost any location. The problem in January to March 2020 was that many unreliable kits for such tests were rolled out mostly by firms looking to cash in, even selling online to the public. The main problem with those test kits was that they either 1) fail to detect antibodies to COVID19 when people have them, or 2) they say you are positive for antibodies to COVID19 BUT you are not.

Using finger-tip blood for tests of this type is very possible, and in fact, there are FDA and European Union approved tests that use this format "lateral flow test" for AIDS and Legionnaires Disease. However, those tests have been around for some time and were of course tested to confirm their reliability. So I approached a particular manufacturer of antibody-based research reagents when I heard they were turning their expertise to making a reliable family of tests for COVID19 antibodies in blood. 

August 20, 2020

Interactive Graphs: COVID19 Cases, Deaths. (updated daily)

Here are graphs that you can adjust to look at different timelines for cases of illness and deaths for any country. I have embedded iFrame code in this posting to give you graphs that you can control. Table and MAP views are also available. You can return here as the data updates automatically.