Efficacy of Covid-19 vaccines
This Blog post might be a bit dull, but it contains information about the performance of the three new vaccines, which are about to be introduced.
First a reminder of Cacifediol
Calcifediol / vitamin D
We have seen that vitamin D in its rapid-acting part-activated form Calcifediol is remarkably effective the treatment of Covid-19 pneumonia. We have seen that its efficacy is 96%, and also how this is worked out.
Proportionate benefit = efficacy = 96%
Absolute benefit = 48%
NNT = 2, meaning that 2 treatment are necessary to prevent 1 ICU admission/death.
In the control group 2 deaths occurred among the 13 patients needing admission to the ICU.
We have also seen that the cost of preventing an ICU admission or death would be approximately £10.
We have also seen that a detailed report from Massachusetts Institute of Technology indicated that the Córdoba RCT of Calcifediol was conducted properly, and that the probability of the positive result being by chance is less than one in a million.
We have seen that the study was rubbished by NICE and as a result it has not been used in the UK. It is likely that since the trial's results were published on September 3rd, 25,500 UK citizens have died from Covid-19. This would have been a much smaller number if the results of the Córdoba study had been put into action, and hospital patients with Covid-19 pneumonia treated with Calcifediol.
Physical or immunological protection?
The government and its advisors have done a great deal in what can only be described as a futile attempt to conquer the air-borne respiratory virus by physical means. It was clear from the outset to people with a knowledge of biological science that the most important approach would be to protect our citizens by mechanisms of immunity.
There would be two approaches to this. One would be to develop a vaccine but that would obviously take time. The vaccines are becoming ready for use at the end of 2020, by when more than 65,000 deaths from Covid-19 will have occurred in the UK. There are still some concerns about vaccine safety.
The other approach would be to optimise innate defensive immunity, and this is best undertaken by correcting widespread vitamin D deficiency. Even before the pandemic developed, it was or should have been well-known in medical–scientific circles that vitamin D is the vital key that unlocks the enhancement of the defensive immune process.
On March 23rd 2020 there had been 285 deaths from Covid-19 in the UK. Lockdown was introduced, with huge social and economic cost. Vaccines were well in the distance, but vitamin D could have been and should have been used to help defend the people while waiting for a safe vaccine to be produced.
The vaccines are now available or are being tested. It is known that in the presence of vitamin D deficiency, vaccines are less likely to produce an immune response.
I have used prices of vaccines that I have seen. More accurate or dependable prices might become available, and can then be substituted.
The Pfizer trial, 1st release “90% effective”
Pfizer released this data to the press.
36,995 subjects recruited into the trial, divided into two equal sized groups 18,497 in each (forget the one extra for now as we were not told which group this person was in).
Placebo 85 cases, no deaths
Vaccine 9 cases, no deaths
This is all the data that we have been given.
What it means is this:
Reduction of cases in the vaccination group is 85 (control) minus 9 (vaccine), equals 76.
Expected number of deaths in vaccine group =
number of deaths in placebo group = 85
Observed number in vaccine group = 9
Cases prevented by vaccine = 85 - 9 = 76
76 prevented out of 85 = (76/85)x100 = 89.411 %
Proportionate reduction of cases = Efficacy = 90%
Control group : 85 cases out of 18477 = 0.46%
Vaccine group: 9 cases out of 18477 = 0.049%
Gain from vaccine = 0.46 - 0.049 = 0.41%
Absolute risk reduction of cases = 0.41%
Number needed to treat
18,497 vaccinations are necessary to prevent (85 - 9) = 76 “cases” (whatever a case might be).
18497 ÷ 76
= 243 vaccines are necessary to prevent one case
243 is the NNT, the number needed to treat to prevent one case.
From this we can calculate the cost of one case prevented, on the basis that the cost of one success must be the sum of the NNT.
We are told that the price of one vaccination (assume a pair of vaccinations in one person) is $20. We assume that this includes distribution and storage costs.
We are told that in the UK there will be a £12.85 ($17.19) doctor administration fee. I will ignore this in the calculations but it will almost double the costs of vaccination.
Cost = $20
NNT 243 x $20 =
$4,860 the cost per case prevented.
Some people would rather have the money.
Deaths prevented (prediction only)
World wide there are 50 times more cases than deaths, ratio of cases to deaths is 50:1.
This means that to prevent one death will require:
243 x 50 = 12,156 vaccinations.
This will result in a cost of
50 x $4,860
= $243,000 to prevent one death.
My family would perhaps rather have the money!
Remember that most deaths are after the age of 80, with life expectancy about ten years =
$24,300 per year gained (quality not considered).
In the UK the ratio of cases to deaths is 25:1
This means that cost per death prevented is half the worldwide average
243 x 25 = 6981 vaccinations to prevent one death = $139,620.
Pfizer trial, 2nd release “95% effective”
43,000 subjects, assumed equally divided.
21,500 placebo, 162 cases
21,500 vaccine, 8 cases
Expected cases = 162
Observed cases = 8
benefit: (162 - 8) = 154
Cases prevented = 154 out of 162
= (154 ÷ 162) x 100 = 95%
Efficacy = 95%
21,500 vaccinations prevented 154 cases
(21,500 ÷ 154) = 140 = vaccinations to prevent one case
140 x $20 per vaccination
= $ 2,800 per case prevented
= $ 140,000 per death prevented (world average)
Control group : 162 cases out of 21500 = 0.753%
Vaccine group: 8 cases out of 21500 = 0.037%
Gain from vaccine = 0.753 - 0.037 = 0.716%
Absolute risk reduction of cases = 0.72%
The publication process is very slow.
On November 12th a paper was published in the New England Journal of Medicine with he results of a phase 1 study involving 45 subjects receiving the mRNA-1273 Covid-19 vaccine. It had appeared as a pre-print on July 14th. The purpose was to define optimal dose.
The results of the clinical trial were released to the press in advance of peer-reviewed publication, and appeared in New Scientist on November 16th.
No conclusions, just observations.
Vitamin D and vaccines are complementary.
Giving vitamin D now would reduce the impact of the Covid-19 pandemic before the vaccines are widely used. Also vitamin D is necessary to activate the immune system so as to allow the vaccine to induce a good response.
Also vitamin D is available now and distribution costs are minimal. There are no costs of storage or administration. Safety is not a concern in the doses recommended (up to 4,000 units daily or equivalent).
Vaccines will not be of help to those who are ill from Covid-19. For this, Calcifediol the part-activated form of vitamin D is essential.