Appendix A: Definitions for Israel Nationwide Pfizer Study
Variable
Definition
Outcomes
Documented SARSCoV-2 Infection
A PCR confirmed infection.
Asymptomatic SARSCoV-2 Infection 0
A PCR-confirmed infection with no report of symptoms during referral and during initial physician questioning.
COVID-19 (symptomatic SARSCoV-2 Infection)
A PCR-confirmed infection with report of symptoms during the PCR referral / during the followup in the community setting / COVID-19 related hospitalization / COVID-19 related death. Existing symptoms were considered when the physician or nurse checked the “symptomatic” option in the EMR, or when the following specific symptoms were recorded: fever or chills, cough, shortness of breath or difficulty breathing, sore throat, headache, weakness, congestion or runny nose, myalgia, nausea or vomiting, diarrhea, abdominal pain, loss of taste or smell, inability to eat or drink.
COVID-19 related hospitalization
A hospitalization that was reported to the Israeli MOH as a hospitalization of a SARS-CoV-2 infected individual.
COVID-19 related severe state
As defined by the hospitalizing institution per the Israeli MOH guidelines, consistent with the NIH criteria for severe illness or critical illness:
Individuals who have SpO2 <94% on room air at sea level, a ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) <300 mm Hg, respiratory frequency >30 breaths/min, or lung infiltrates >50%.
Critical Illness: Individuals who have respiratory failure, septic shock, and/or multiple organ dysfunction.
COVID-19 related death
A death of a SARS-CoV-2 infected individual reported to the Israeli MOH.
Vaccination Periods
Days 14-20
From the 14 days until 20 days after the first dose
Days 21-27
From 21 days and until 27 days after the first dose
Days 0-6 after the 2nd dose
From the 2nd dose and until 6 days later
Days 7+ after the 2nd dose
From day 7 after the 2nd dose and until the end of the follow-up
2021/5/13 I’ve now had a chance to look into variants. Based on: (1) the result from this large study from Qatar, (2) the current prevalences of variants in the US, and (3) the assumption that other variants of concern are no more vaccine-resistant than B.1.351, (4) the current prevalence of variants in the US as per outbreak.info, I conclude that vaccine effective I believe that vaccine effectiveness against getting Covid at all is reduced by a factor of 0.95; however, vaccine-effectiveness against severe disease and death is probably not reduced.
In conclusion, within the United States, I believe that the results of this overall still hold. Huzzah!
2021/4/24 I’ve now spent some time looking into variants and how they might affect vaccine effectiveness. Currently, it seems clear that: (1) certain variants are already pretty widespread and gaining in prevalence in quickly, (2) some of those variants have lab/in- vitro evidence of decreased effectiveness. What is unclear is the real-world clinical significance. I don’t know enough immunology and haven’t read enough to know.
In my current poor epistemic state of ignorance, I would currently guess that vaccines offer somewhat less than 99% effectiveness (for young people against symptomatic), but probably still pretty high, say upwards of 80% or even 90%. And effectiveness against more severe cases is probably still higher. But everything lower confidence than when I wrote this post.
If I can get the chance, I’ll look into this more and provide more updates. For those interested, outbreak.info is an utterly amazing source of data on variants and mutations–both dashboards and collections of relevant papers.
2021/4/22
I removed a short section discussing different false-positive rates among different levels of severity that I now think was confused, following the exchange in this thread.
2021/4/17
I added a subsection in the Objections section discussing how the vaccine and control groups in the big Israeli study might be different, and how this should widen confidence intervals.
APPENDICES & FOOTNOTES
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Appendix B: Breakdown of End Points by Vaccination Status and Time Period for Israel Mass Pfizer Study
Appendix A: Definitions for Israel Nationwide Pfizer Study
As defined by the hospitalizing institution per the Israeli MOH guidelines, consistent with the NIH criteria for severe illness or critical illness:
Individuals who have SpO2 <94% on room air at sea level, a ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) <300 mm Hg, respiratory frequency >30 breaths/min, or lung infiltrates >50%.
Critical Illness: Individuals who have respiratory failure, septic shock, and/or multiple organ dysfunction.
Updates / Changelog
2021/5/13
I’ve now had a chance to look into variants. Based on: (1) the result from this large study from Qatar, (2) the current prevalences of variants in the US, and (3) the assumption that other variants of concern are no more vaccine-resistant than B.1.351, (4) the current prevalence of variants in the US as per outbreak.info, I conclude that vaccine effective I believe that vaccine effectiveness against getting Covid at all is reduced by a factor of 0.95; however, vaccine-effectiveness against severe disease and death is probably not reduced.
In conclusion, within the United States, I believe that the results of this overall still hold. Huzzah!
2021/4/24
I’ve now spent some time looking into variants and how they might affect vaccine effectiveness. Currently, it seems clear that: (1) certain variants are already pretty widespread and gaining in prevalence in quickly, (2) some of those variants have lab/in- vitro evidence of decreased effectiveness. What is unclear is the real-world clinical significance. I don’t know enough immunology and haven’t read enough to know.
In my current poor epistemic state of ignorance, I would currently guess that vaccines offer somewhat less than 99% effectiveness (for young people against symptomatic), but probably still pretty high, say upwards of 80% or even 90%. And effectiveness against more severe cases is probably still higher. But everything lower confidence than when I wrote this post.
If I can get the chance, I’ll look into this more and provide more updates. For those interested, outbreak.info is an utterly amazing source of data on variants and mutations–both dashboards and collections of relevant papers.
2021/4/22
I removed a short section discussing different false-positive rates among different levels of severity that I now think was confused, following the exchange in this thread.
2021/4/17
I added a subsection in the Objections section discussing how the vaccine and control groups in the big Israeli study might be different, and how this should widen confidence intervals.