CME INDIA Presentation by Dr. Rajeev Jayadevan, MD, DNB, MRCP, ABIM (Med) ABIM (Gastro), NY. Vice Chairman, Kerala state IMA Research Cell. Member, National IMA Task Force on Corona Epidemic, Cochin.

A Case of Overstated Reporting?

Never Blindly Believe Author’s Conclusions

Has Israel’s 4th dose study been reported in an exaggerated manner?

  • Israel 4th dose study has been reported in an exaggerated manner by several media (and western ‘Twitter celebrities’).
  • To understand the truth, I spent a few hours studying the preprint: see my notes attached for the summary.

Has Israel’s 4th dose study been reported in an exaggerated manner?


  • Some studies from Israel had repeatedly “boosted” public opinion and perception of boosters.
  • Many media are already quoting the preprint authors conclusions, obviously without looking at the data.

What is the problem with the study?

  • In any study, the main data must be clearly laid out. When that does not happen, it is a red flag 🚩
  • Good studies will clearly lay out the most important data.
  • This one tries to hide it behind statistical jargon.

E.g., in a study that compared two groups of people who got 3 and 4 doses each, readers are interested in knowing some basic facts.

  1. How many got infected in each group? (This data is not available, see my notes for details)
  2. How many got severe disease?
  3. How many died?

Some data are there, but hidden deep inside tables in the appendix

  • One has to sit down with a pencil, paper and a calculator to dig out even these basic parameters. I have dissected and laid them out.

Has Israel’s 4th dose study been reported in an exaggerated manner?

Let me explain what the chief observations are (most of them I have already written on my notes posted)

  1. They studied people over average age of 70. This is important, as severe COVID outcomes are more likely to occur in this age segment. However, deaths were very very rare in both 3rd and 4th dose groups.
  2. The aim of vaccination is primarily to reduce the chance of severe disease & death. But when we look at raw numbers, it is clear there is no difference between the 3rd or 4th dose groups.
  3. There was a high rate of infection, even after three doses of vaccination. This to me is the most important finding, up to 22.9% of tests were positive. This shows that boosters, even 3 doses – were not protecting against infection adequately. This was Omicron wave. This crucial point is not even mentioned in the paper.

Has Israel’s 4th dose study been reported in an exaggerated manner?

  1. The infection rate in the 4-dose group was less than 3 dose. This makes sense- because in the initial 10 weeks following a vaccine dose, there is a protective window of neutralising antibodies.
  2. Unfortunately, with every additional dose, this window gets smaller. This is called the principle of diminishing returns.
  3. Authors report that the additional protective effect of 4th dose (against infection) dropped to 29% in only one and half months.

Has Israel’s 4th dose study been reported in an exaggerated manner?

If We Tortured Data Long Enough, It Will Confess to Anything We Want

  • Statisticians thrive on exaggerating tiny differences.
  • Let me give an example.
  • When we look at our right hand & our left hand, there will be a marginal difference in measurements between the two.
  • A statistician can exaggerate this on a graph, and make it seem as though the right hand is HUGE, while the left is TINY.
  • That’s the power of statistics.
  • Of course, when we look at both our hands 🖐 🖐, for all practical purposes they seem the same; the difference shown in the pretty graph does not make a real-life difference for us.

🚩Many studies do this trick to get attention

  • Many people look ONLY at the authors’ conclusions. Authors sometimes exaggerate what they actually found, while hiding more important things.
  • How not to be fooled while reading research studies? Read more here.

CME INDIA Tail Piece

Has Israel’s 4th dose study been reported in an exaggerated manner?


1. Relative Effectiveness of Four Doses Compared to Three Dose of the BNT162b2 Vaccine in IsraelSivan Gazit, Yaki Saciuk, Galit Perez, Asaf Peretz, Virginia E. Pitzer, Tal Patalon medRxiv 2022.03.24.22272835; doi:

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