The “leaked” Pfizer documents are actually really boring
This post does not have a summary because I felt that I could not make this any shorter without sacrificing key points. I have done my best to keep this post as brief as possible. I made a twitter thread explaining the problems with the pervasive misinterpretations of the document takes and this post is basically a cleaned-up version of that.
About 3 months ago, some documents were released through a Freedom of Information Act (FOIA) request (from a group of individuals more or less overtly hostile to COVID-19 vaccines), describing pharmacovigilance data from Pfizer after their vaccine had been rolled out which has recently gotten a lot of attention with proclamations like “the vaccine has 9 pages of terrifying side effects!” and cries of vindication from those opposing its use. FOIA requests are frequently abused by anti-vaccine activists to make misleading claims about vaccines; FOIA requests tend to have very specific questions and thus if there isn’t something explicitly addressing them, the response is typically something like “We have no records responsive to your request,” which is then taken to represent that these apparently critical studies were not done. For example, not too long ago there was a FOIA request addressed to the CDC asking them for reinfection data that they did not collect, which was immediately spun to mean that reinfections were not occurring. There’s a similar thing happening here, although it’s not quite the same. Here, however, it is actually just a matter of understanding the specific jargon of clinical trials rather than any complex scientific reasoning- it’s really boring. The misconceptions spanning this document really run the gamut, so let’s get into it:
Who are these data about?
As part of the pharmacovigilance plan (i.e. safety monitoring) for the Pfizer/BioNTech COVID-19 vaccine (Bnt162b2), Pfizer is responsible for safety monitoring of the product in the real world (they are not the only entity responsible however), and it is expected to share these findings with regulators like the FDA and EMA. One key point of confusion I’ve observed with this document is the population it describes. It is NOT about the phase 2/3 clinical trial participants receiving the vaccine- it is about the use of the vaccine in the real world from its release on December 1, 2020 until February 28, 2021 and it contains spontaneous reporting data about the vaccine’s use in the real world, similar to VAERS (and therefore has limitations similar to it). Spontaneous reporting means that someone has to go and voluntarily report it, as opposed to active surveillance where people are followed and monitored. I think the reason for this misconception is the number of individuals for which there are adverse events being similar to that of the number enrolled in the aforementioned clinical trials. But if you read the document, it’s very clear that the data described are not from Pfizer’s clinical trial. Specifically:
Because it describes spontaneous reporting, it cannot be Pfizer’s own clinical trial because that is active surveillance:
Reports are submitted voluntarily, and the magnitude of underreporting is unknown. Some of the factors that may influence whether an event is reported include: length of time since marketing, market share of the drug, publicity about a drug or an AE, seriousness of the reaction, regulatory actions, awareness by health professionals and consumers of adverse drug event reporting, and litigation.
To clarify, active surveillance means that people are enrolled in advance and tracked for some period, like what is done with V-SAFE and its regular check-ins among those who register for the service. The goal of active surveillance is to track adverse events as completely as possible and it’s usually accomplished through the use of large linked medical databases that contain the medical records of millions of people.
It notes reporting from multiple sources, including public health authorities:
Pfizer’s safety database contains cases of AEs reported spontaneously to Pfizer, cases reported by the health authorities, cases published in the medical literature, cases from Pfizer-sponsored marketing programs, non-interventional studies, and cases of serious AEs reported from clinical studies regardless of causality assessment.
whereas in the clinical trials, the only source could be from the trial investigators and their teams.
So to state it explicitly, no, 3% of Pfizer’s trial participants didn’t die after enrollment over this 3 month period of surveillance. These data reflect spontaneous reporting across millions of doses of vaccine (it’s hard to estimate exactly how many because Pfizer redacts the number; I am not sure what the reason for it is but it’s honestly not that important anyway because these data can’t be used to reliably estimate the rates of the reported adverse events because they are the result of spontaneous reporting). Airfinity global estimates that 119 million doses were cumulatively produced during that time period and Our World in Data suggests about 68 million doses were given out across the US and EU which likely account for most of the doses at that point in the pandemic. If we take the worst-case scenario that everyone received 2 doses out of these 68 million, that’s 34 million people included in the analysis as the minimum number, though for at least some of these, there was only 1 dose given, so the actual number is bigger than that. Note additionally that this early on in the vaccine rollout, the main groups receiving the vaccines were high-risk and elderly patients, and healthcare workers. Of this sample, 42,086 individuals reported some kind of adverse event which Pfizer was able to access in their safety analysis. Note however that these adverse events do not have to be directly reported to Pfizer because, once more, as explicitly stated:
Pfizer’s safety database contains cases of AEs reported spontaneously to Pfizer, cases reported by the health authorities, cases published in the medical literature, cases from Pfizer-sponsored marketing programs, non-interventional studies, and cases of serious AEs reported from clinical studies regardless of causality assessment.
In other words, you do not have to go and physically contact Pfizer for the adverse event to be captured in this surveillance system, so comments that no one you know did that are not relevant.
From here things get dry because the rest of the misinterpretations are based on not understanding the specialized jargon of clinical trials, so now we have to run through some definitions.
The meaning of words
One of the major problems with the interpretations of this report is that people do not have a solid grasp of what an adverse event is. I think most people hear the term and they think that it’s a side effect- an unwanted but expected outcome of receiving some intervention (that’s not a formal definition but I expect that the people using that term are not referencing any formal definition so I think it’s fine). In reality, the term side effect appears nowhere in this entire report, and for good reason. As is described in this document from the EMA:
The old term "side effect" has been used in various ways in the past, usually to describe negative (unfavourable) effects, but also positive (favourable) effects. It is recommended that this term no longer be used and particularly should not be regarded as synonymous with adverse event or adverse reaction.
So what is a side effect as used commonly in the parlance of clinical trials? The WHO does have a definition for side effect here though, as above, the term is not generally appropriate for use in the context of safety monitoring of medications. The closest thing is probably an adverse drug reaction (ADR), or sometimes just adverse reaction for short (from that same EMA document):
A response to a drug which is noxious and unintended and which occurs at doses normally used in man for prophylaxis, diagnosis, or therapy of disease or for modification of physiological function.
So what then is an adverse event? The CIOMS has graciously assembled a glossary where it presents the definitions of commonly used terms in clinical trials (and even has a section on vaccine-specific ones) and also cites the source of those definitions (which are usually from the WHO, ICH, or regulators like the FDA or EMA). Because it typically gives multiple definitions from multiple sources, for simplicity, I will use the most comprehensive one for each term. Under adverse event (emphasis mine):
Adverse event (AE) (CIOMS VIII) Any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product which does not necessarily have a causal relationship with this treatment.
Note: An adverse event can therefore be any unfavourable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product.
Note that adverse events are tracked even for those who are in the placebo group, especially if the study is blinded (meaning that the participant or investigator or data analysts do not know who is receiving the placebo or active agent; the term “blinding” however is a bit of a can of worms because terms like double-blind are not consistently used in the literature and may mean different things so now it is considered best practice to state explicitly who is being blinded e.g. observer-blind).
Adverse events get graded based on their severity and also classified as serious, non-serious, or life-threatening. The grading system for vaccines used by the CBER (the division of the FDA that evaluates them) is a little bit different from that used by other divisions of the FDA that evaluate non-biologic medications, but in generally severity is graded on a 4-point scale:
Grade 1: Mild
Grade 2: Moderate
Grade 3: Severe
Grade 4: Potentially life-threatening
The exact meaning of each grading depends on the specific outcome e.g. pain vs fever cannot be defined in the same way because pain is a subjective finding whereas we can measure body temperature and define ranges for each of these. The term severe is often conflated with the term “serious” in this context. As per CIOMS:
Severe/Severity (CIOMS IV) The term severe is not synonymous with serious in this context. Severe is used to describe the intensity (severity) of a specific event (as in mild, moderate or severe myocardial infarction). Proposed by CIOMS Working Group IV.
In contrast, serious and life-threatening are described by CIOMS (emphasis mine):
Serious adverse event or reaction (CIOMS VII) Any untoward medical occurrence that at any dose:
- Results in death
- Is life-threatening*
- Requires in-patient hospitalisation or prolongation of existing hospitalisation
- Results in persistent or significant disability/incapacity, or
- Is a congenital anomaly/birth defect
Medical and scientific judgement should be exercised in deciding whether expedited reporting is appropriate in other situations, such as important medical events that may not be immediately life-threatening or result in death or hospitalisation but may jeopardise the patient or may require intervention to prevent one of the other outcomes listed in the definition above. These should usually be considered serious as well. Examples of such events are intensive treatment in an emergency room or at home for allergic bronchospasm; blood dyscrasias or convulsions that do not result in hospitalisation; or development of drug dependency or drug abuse.
*The term “life-threatening” refers to an event or reaction in which the patient was at risk of death at the time of the event or reaction; it does not refer to an event or reaction which hypothetically might have caused death if it were more severe.
Adopted from: ICH Guideline E2A: Definitions and Standards for Expedited Reporting and ICH Guideline E2D: Postapproval Safety Data Management – Note for Guidance on Definitions and Standards for Expedited Reporting. In the EU Directive 2001/20/EC on Clinical trials: “Serious Adverse Event or Serious Adverse Reaction” – any untoward medical occurrence or effect that at any dose results in death, is life-threatening, requires hospitalisation or prolongation of existing hospitalisation, results in persistent or significant disability or incapacity, or is a congenital anomaly or birth defect. Commentary: The ICH definition of a serious adverse event (AE) or adverse drug reaction (ADR) has been adopted for post marketing applications in ICH Guideline E2D. The EU definition given above is considered by the CIOMS Working Group as incomplete without the paragraph beginning with “Medical and scientific judgement…” in the ICH definition
When it comes to vaccines, the term adverse event following immunization (AEFI) is sometimes used:
Any untoward medical occurrence which follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine. The adverse event may be any unfavourable or unintended sign, abnormal laboratory finding, symptom or disease.
So why the distinction? In practice, especially when the medication is still new so not that many people have received it, it can be very hard to tease apart what events are coincidental vs. actual adverse reactions to the medication. Investigators in clinical trials are asked to make an assessment of causality for each adverse event based on their expertise about the medication and best judgment, and these get reviewed by the sponsor of the trial (in this case Pfizer) and by regulators like the FDA who also assess for causality (for a detailed discussion of how causality is assessed for vaccines, here is a discussion from the WHO). For example, in the Phase 2/3 trial for Bnt162b2 vaccine, one participant with a history of heart issues experienced a ventricular arrhythmia after vaccination which the investigator assessed as related, but the Sponsor assessed as unrelated, and FDA reassessed as being unrelated to the vaccine. Sometimes it’s a bit silly though. For example, as I’ve mentioned before on this blog, the package insert for Gardasil notes that there were 4 deaths related to gunshot wounds in its clinical trials (1 in the vaccine group and 3 in the placebo group), which we can say with a high degree of confidence, I think are unrelated to the vaccine. But, it’s important to track everything because sometimes adverse events that seem unrelated to the intervention turn out to actually be related to the intervention on further investigation. We never know everything about any given medication, and truthfully we don’t need to. We just need to know enough about it to know whether or not the benefits of its usage outweigh the risks. Furthermore, there are typically costs to learning these things. For instance, the only way to get information about whether or not a vaccine is protective against COVID-19 is a study that allows people to get COVID-19 and compares the rates among the vaccinated and unvaccinated- and this can be fatal or disabling for the participants who get COVID-19. For that reason, monitoring of any medication is continued long after the product is approved through a number of mechanisms.
In the context of spontaneous reporting, you are not attempting to test a hypothesis per se i.e. does this adverse event occur more frequently than the background rate among recipients of the vaccine? That kind of question requires active surveillance like what can be done with the Vaccine Safety Datalink. Instead you are trying to look for signals. “Signal” (or “safety signal”) is a bit complex to define, and the discussion from Hauben and Aronson is extremely thorough; the most informative definition of a signal I could find was from the FDA:
Pharmacovigilance principally involves the identification and evaluation of safety signals. In this guidance document, safety signal refers to a concern about an excess of adverse events compared to what would be expected to be associated with a product's use. Signals can arise from postmarketing data and other sources, such as preclinical data and events associated with other products in the same pharmacologic class. It is possible that even a single well-documented case report can be viewed as a signal, particularly if the report describes a positive rechallenge or if the event is extremely rare in the absence of drug use. Signals generally indicate the need for further investigation, which may or may not lead to the conclusion that the product caused the event. After a signal is identified, it should be further assessed to determine whether it represents a potential safety risk and whether other action should be taken.
In a practical sense, if there is a sudden spike in reports for a particular adverse event, i.e. more frequently than would be expected (like if the condition is very rare), then that’s a signal that should be investigated by active surveillance (what in the CIOMS glossary version 1.1 is described as “Active vaccine safety surveillance”). For example, there was an unusual spike in the incidence of thrombosis with thrombocytopenia syndrome in recipients of the JJJ vaccine, which was detected extremely rapidly through spontaneous reporting despite having an incidence less than 1 per 100,000 individuals.
The key type of adverse event to understand here though is an adverse event of special interest or AESI (alternatively called a TME, targeted medical event), which are what some people are extremely incorrectly calling the 9 pages of side effects (emphasis mine):
Adverse event of special interest (CIOMS VII) An adverse event of special interest (serious or non-serious) is one of scientific and medical concern specific to the sponsor’s product or programme, for which ongoing monitoring and rapid communication by the investigator to the sponsor may be appropriate. Such an event may require further investigation in order to characterize and understand it. Depending on the nature of the event, rapid communication by the trial sponsor to other parties may also be needed (e.g., regulators). Adopted from: CIOMS VI Working Group
Commentary: An adverse event of special interest is a noteworthy event for the particular product or class of products that a sponsor may wish to monitor carefully. It could be serious or non-serious (e.g., hair loss, loss of taste, impotence), and could include events that might be potential precursors or prodromes for more serious medical conditions in susceptible individuals. Such events should be described in protocols or protocol amendments, and instruction provided for investigators as to how and when they should be reported to the sponsor.
Whenever a clinical trial is conducted, there is a protocol written that describes in detail any information you would ever need to know about the trial, including a list of adverse events of special interest. These are typically written into protocols before the trial is ever conducted and new ones can be added with a protocol amendment. The 9-page long list in the end of this pharmacovigilance document is a list of things that Pfizer wanted to know about immediately if they occurred- not things that actually occurred to people. Beyond this, even if they were actual adverse events that happened to people, without information on whether or not they generated a signal and detailed information on the cases, that information in isolation would not be meaningful because any of the events could be coincidence. For example, the document reports 1223 fatal adverse events- but in a group of more than 34 million people, the bulk of which would be individuals who are at very high risk from COVID due to advanced age or comorbidities, you would expect far more than that to occur by random chance alone if you followed them for a 3-month period. To give a more concrete example to it, as pointed out by Dr. Bob Wachter, if we follow any random group of 10 million people in the US for 2 months and *do nothing,* we would expect to see about 4000 heart attacks and strokes, 9500 cancer diagnoses, 60 cases of multiple sclerosis, and 14,000 deaths. This happens whether or not they get vaccinated. Those numbers will be significantly higher (at least for heart attacks and strokes) if you examine a group of individuals who are in the first place at much higher risk due to advanced age, if the group is much larger than 10 million as is the case here, and if you examine them for 3 months instead of 2.
One more definition that is worth knowing is the Brighton Collaboration. One of their most important roles is to create standardized case definitions for adverse events so that they can be properly assessed epidemiologically in a consistent manner (you can go through their publications here) and to explain what criteria constitute what level of certainty for the case (ranked 1-5 which correspond to a definitive case down to a possible case respectively).
What does the document actually say about the safety of the vaccine in the real world?
The great irony of people sharing this document horrified about how dangerous the Bnt162b2 vaccine is because of the data contained within is that there are multiple instances where the document states explicitly that there are no significant safety concerns identified and that the risk-benefit ratio for the vaccine remains highly favorable. For instance, from the very end of the document (emphasis mine):
4. DISCUSSION Pfizer performs frequent and rigorous signal detection on BNT162b2 cases. The findings of these signal detection analyses are consistent with the known safety profile of the vaccine. This cumulative analysis to support the Biologics License Application for BNT162b2, is an integrated analysis of post-authorization safety data, from U.S. and foreign experience, focused on Important Identified Risks, Important Potential Risks, and areas of Important Missing Information identified in the Pharmacovigilance Plan, as well as adverse events of special interest and vaccine administration errors (whether or not associated with an adverse event). The data do not reveal any novel safety concerns or risks requiring label changes and support a favorable benefit risk profile of to the BNT162b2 vaccine.
5. SUMMARY AND CONCLUSION Review of the available data for this cumulative PM experience, confirms a favorable benefit: risk balance for BNT162b2. Pfizer will continue routine pharmacovigilance activities on behalf of BioNTech according to the Pharmacovigilance Agreement in place, in order to assure patient safety and will inform the Agency if an evaluation of the safety data yields significant new information for BNT162b2.
But, rather than just say that, let’s go through it table by table to show how they arrive at this conclusion. The first table of interest is Table 2, which describes adverse events experienced by at least 2% of the cases. None of them are serious (in the formal sense of the word), and nearly all of them describe reactogenicity symptoms- symptoms that occur from the inflammation caused by the vaccine that indicate the vaccine is initiating an immune response. Reactogenicity symptoms are in general short-lived and do not represent safety concerns, even if they are uncomfortable, and the absence of these symptoms does not indicate that the vaccine is not working. COVID-19 is mentioned because some people reported that they got COVID-19 after being vaccinated. This makes sense- the vaccine is not 100% effective.
Table 3 goes into identified safety concerns, potential risks, and missing information, which are further elaborated upon in Tables 4, 5, and 6. Of everything in the document this is the most outdated. Early on in the rollout of the Bnt162b2 vaccine, there were a few reports of anaphylaxis, which did not occur in the clinical trials. Anaphylaxis is a serious, potentially life-threatening allergic reaction that is fortunately very treatable and can occur after exposure to almost anything you can think of (e.g. alcohol, exercise, cold, UV radiation, etc.) and so it’s important to know if the vaccine is causing this at an unusually high rate. For commonly used vaccines, the rate has been estimated at about 3 per million doses; Today, the rate of anaphylaxis following the Bnt162b2 vaccine seems to be about 5 per million, similar to that of other routinely used vaccines. Because this report is generated via spontaneous reporting however, it is not able to estimate a rate. Without access to the primary data however, we can’t really contradict their conclusion about their data, which reads:
Conclusion: Evaluation of BC cases Level 1 - 4 did not reveal any significant new safety information. Anaphylaxis is appropriately described in the product labeling as are non-anaphylactic hypersensitivity events. Surveillance will continue.
In other words, no substantially elevated risk of anaphylaxis was observed in this 3-month period, consistent with later data on the matter.
Another matter was the potential risk of VAERD (vaccine-associated enhanced respiratory disease), which I discussed in the end of this post. VAERD refers to a phenomenon where the respiratory disease gets worse after vaccination rather than the vaccine being protective; principally it has been an issue with inactivated RSV vaccines, but it is something that is closely watched for any vaccine for a respiratory virus, hence its inclusion in this document. Among recipients of the inactivated RSV vaccine, there was a very clear trend to more severe disease among the vaccinated compared with the placebo group. Pfizer’s report writes:
Conclusion: VAED may present as severe or unusual clinical manifestations of COVID-19. Overall, there were 37 subjects with suspected COVID-19 and 101 subjects with confirmed COVID-19 following one or both doses of the vaccine; 75 of the 101 cases were severe, resulting in hospitalisation, disability, life-threatening consequences or death. None of the 75 cases could be definitively considered as VAED/VAERD. In this review of subjects with COVID-19 following vaccination, based on the current evidence, VAED/VAERD remains a theoretical risk for the vaccine. Surveillance will continue
In other words, no clear evidence of VAERD among recipients of the vaccine. This is consistent with the data from every vaccine effectiveness study on Bnt162b2 I have seen to date, which show that protection from severe COVID-19 is robust and durable in most individuals e.g. this study.
One piece of information in this section is about missing information e.g. the use of Bnt162b2 among pregnant and lactating individuals and its use in children. Regarding children, we have data from large randomized controlled trials showing safety and effectiveness down to age 5, and surveillance data therein also supporting both safety and effectiveness. The safety of the vaccine’s use in lactating individuals is summarized by the Lactmed entry which notes that the vaccine in general does not appear to end up in the breastmilk (even if it does, it’s meaningless because it will be destroyed by the baby’s digestive tract), and antibodies against the spike protein are passed to the baby. Personally, I am skeptical that this offers significant protection against COVID-19 (in contrast to transplacental antibodies), but I think it is plausible that it could be protective against MIS-C. Regarding the use in pregnant individuals, there are regulatory and bureaucratic hurdles to doing such a formal randomized controlled trial in these individuals but we have plenty of data showing both safety and effectiveness. For a sampling: this, this, this, this, and the studies linked in response to question 8 in this (which is a phenomenal resource and I am so grateful to Dr. Male for making it).
Table 7 has to do with an AESI evaluation of certain select events. Once more, the goal here is signal detection, rather than hypothesis testing. This report notes that Pfizer did not find any safety signals for COVID-19 AESIs, dermatological AESIs, hematological AESIs, hepatic AESIs, facial paralysis, Immune-Mediated/Autoimmune AESIs, Musculoskeletal AESIs, Neurological AESIs (including demyelination), Other AESIs, Pregnancy Related AESIs, Renal AESIs, Respiratory AESIs, Thromboembolic Events, Stroke, or Vasculitic Events. It’s true that spontaneous reporting can underreport issues, but usually for serious adverse events this is less of a problem. It is worth noting however that myocarditis was an AESI in their list and yet did not generate a signal. The most likely explanation for this is that myocarditis is an adverse event that occurs almost exclusively in younger males, and at this point in the vaccine rollout, almost none of them were getting the vaccine (rather than that Pfizer was just extremely careless in their data analysis and/or sought to minimize everything- that’s really not in their best interest because if they don’t detect these problems and then it shows up later through other investigations, it undermines trust in their product and their stock prices take a hit).
Following this section, there is a discussion of medication errors i.e. instances where the vaccine was given incorrectly. In general, these seemed to be rare occurrences, and were not associated with significant harms. The report does note that there were 7 deaths that occurred after a medication error, but Pfizer does not believe they are related to the product. Given the number of people observed in this dataset, it’s very much plausible that the deaths were coincidental but without detailed reports of each case, we can’t make firm judgments. This has an easy fix though: administer the vaccination correctly.
Finally, the much-dreaded appendix I. Now, it’s very lengthy and I have very little doubt that the people disseminating this as proof of Pfizer’s vaccine being extremely unsafe did not even attempt to read it (although maybe they did and just don’t care about lying) but the first clue that this isn’t a list of side effects is that the first term is a genetic condition you are born with, and it also includes things like:
Adverse event following immunisation… COVID-19 prophylaxis;COVID-19 treatment… Exposure to communicable disease;Exposure to SARS-CoV-2;
etc. If you actually read the document however, they explain:
The company’s AESI list takes into consideration the lists of AESIs from the following expert groups and regulatory authorities: Brighton Collaboration (SPEAC), ACCESS protocol, US CDC (preliminary list of AESI for VAERS surveillance), MHRA (unpublished guideline). The AESI terms are incorporated into a TME list and include events of interest due to their association with severe COVID-19 and events of interest for vaccines in general. The AESI list is comprised of MedDRA PTs, HLTs, HLGTs or MedDRA SMQs and can be changed as appropriate based on the evolving safety profile of the vaccine.
Meaning they are things that were recommended to be added for monitoring by authorities like the Brighton Collaboration, ACCESS protocol, CDC, and MHRA. In other words, pre-specified adverse events that Pfizer wanted to be notified about immediately if they occurred so they could track them.
But I hear you: why should we trust Pfizer to analyze their own product for safety? We don’t have to. For example, just recently a report of both passive and active surveillance was published by the CDC examining both passive surveillance (VAERS) and active surveillance (V-SAFE) to look at more than 298 million vaccine doses and it found… most adverse events were mild and transient and serious adverse events were very rare. Another report from a team in McMaster University in Canada found that the chance of a serious adverse event with a COVID-19 vaccine was significantly lower than that from a number of commonly used medications. We also have studies examining the safety of the vaccine in specific patients e.g. those with autoimmune and rheumatic diseases. The literature is more or less inundated with these but the conclusion is essentially universal: aside from the rare risk of myocarditis (which is generally mild as in comparison to classic cases of myocarditis and occurs almost exclusively in younger males), the vaccine does not demonstrate any substantial safety issues and shows excellent effectiveness against COVID-19. So you very well could choose to disregard everything in this report after now understanding it (I hope) on the basis that it was a report from Pfizer about Pfizer’s product, but if you honestly examine the literature, you will see that the conclusions from this report are broadly correct subject to the limitations it faced with its subject pool.
Why is it taking so long for Pfizer to release their clinical trial data?
Another misconception I’ve seen is that these documents explain why Pfizer was “so reluctant” to comply with the FOIA requests to see their raw clinical trial data on every single participant- because the data in this pharmacovigilance report are so damning (except, as we have at this point established, they are not). This is also really boring- the raw clinical trial data contains a lot of confidential medical information about the participants in the trials, potentially over 100 pages for each participant, which needs to be redacted to protect the privacy of the participants if it is to be released to the public by a FOIA request. With more than 40,000 participants in the trial, who are all being followed for at least 2 years, this would readily mean hundreds of thousands of pages (in fact the FDA estimated 329,000 pages) that have to be redacted to protect participant privacy. And that takes time to do and it’s not really a priority for officials in the FDA who have already evaluated all of this data before. For further details, I highly recommend Professor Dorit Reiss’s explanation here.
