Clinical Trial and Vaccine Efficacy

One month after the second dose of Covid vaccine, my colleague from Railway Hospital, Jatni became Covid positive.
Admitted to Amri Hospital.

I’ve investigated the case.

 • 5 days before his symptoms, he has attended a marriage party without masks and exposed to a person who became Covid positive (later on).

 • He was admitted only because he was an aged doctor with Comorbidity and hospital didn’t want to take a chance.

 • His recovery was uneventful.

Two other colleagues from Vizag hospitals who became positive.
( one was partially vaccinated, the other has voluntarily not taken).
None from Bhubaneshwar, thank God.

So apparently the vaccine is not at fault. Then why such a confusion about efficacy.

Who is at fault then ?

Having said this, I must say that the design of the Clinical trial protocol for every Covid-19 vaccine (that has received EUA at present) is suspect.

EUAs ( Emergency Use Authorisation) of Covid vaccination is a political decision rather than based on solid science. There are many flaws in the design.

 • Vaccines typically require years of research and testing before reaching the clinic. But we have got a vaccine within 300 days of isolating the culprit. Believe me, it’s not a credit. We are confused because of this haste.

 • PRECLINICAL TESTING

Normally, Scientists test a new vaccine on cell culture and then give it to animals such as mice or monkeys to see if it produces an immune response. That is time taking but gives you a lot of elbow room to try different doses, different schedules. After all animals are expandable. But not the humans. No animal trial has been done in all the Vivid vaccine trials.

That is a blunder. Emergency can’t justify bypassing the beaten scientific method. If one maker was allowed the concession on emergency ground, rest of the vaccine makers have jumped the line. Regulators have to keep mum. You can’t allow one sheep to run and then try to block the rest of the flock.

Three phase trial was bypassed
 • Human Trials should have 3 phases. In many of the authorised vaccines, it is compressed to two.
Why ? Emergency . All the candidate vaccine makers have followed suit.

How do we assign efficacy figures?

Let us understand How the Vaccine Efficacy is calculated.

A simplified approach is

 • Vaccine protective efficacy VE= 1 – ARV/ARU.

where ARV is the _disease attack rate_ in the vaccinated group and ARU is the disease attack rate in the controls.

 • For Pfizer, Target end point was 170 cases.

ARV = 8 ; ARU = 162

VE= 1- 154/162= .95 ~95%

It seems quite accurate. Period.

There are a many caveats

In nearly 30000 sample size what should be the actual Attack rate. .170. Certainly much more than that.

A disease attack rate must account for all those who turned RTPCR positive starting from two weeks after administration of complete vaccination.

They should have a schedule of repeated RTPCR test of each and every member to reach the actual Disease attack rate before un-blinding the trial.

Peculiarly they have taken a figure of first 170 positive cases only if they became moderate to severely sick.

The definition is diabolical. What if we are missing asymptomatic cases. We know 85% or more Covid cases are asymptomatic. The effect of vaccine was never studied on asymptomatic infection. Again Emergency.

How many corners you can cut in the name of emergency.

The Clinical Trial was totally controlled by the giant vaccine makers. Regulators are controlled by their political bosses. Political parties are financed Giant MNCs. Vaccine efficacy was a casualty of this CARTEL. That is bad luck for the humanity at large.


What I feel- the regulators should have gone on doing RTPCR tests of each and every member enlisted for trial rather than selecting a random *170* number of mod to severe cases to assess Vaccine Efficacy.

The basic fault in my opinion is the high profile announcement: 95% efficacy That certainly is misunderstood. When positive cases turned out after full vaccination, it is downgraded to 95% against only hospitalisation and fatality. Which means you will get the infection but you will not die ? This is an unmeasurable quantity. There is no precedence till date of such diabolical definition of a vaccine efficacy. As it is, 95% of Covid infected do not die. Should we level it as efficacy of not getting vaccinated.?

Influenza vaccine confers only 60-70% protection. It also has to be be repeated annually. It still sells in the market with this bottom line . That’s fine for such viruses. People will accept this. It is unfortunate to rig the vaccine design to come out with an exaggerated figure.

But these are changing times. First a mortal fear was created. That pushed up ventilator sale. Now we know all those ventilators we’ve procured are money wasted. Then a vaccine with an aura ( 95% efficacy) was created. And now we know that even if you get the vaccine, you still can get the virus but you won’t die. No science to support this.

Only time will tell about such tall claims.