Yellow CARD analysis

Data is a precious thing and will last longer than the systems themselves.

– Tim Berners-Lee


Our analysis of the Medical & Healthcare products Regulation Agency (MHRA) Yellow Card Scheme for COVID-19 vaccines uses the publicly available reports that are released by the MHRA – initially weekly and then monthly.  Regrettably, the MHRA overwrites the report each time, so the only download available to the general public at any given time is the summary at that particular point.  Without access to preceding reports, the snapshot their document provides allows for little analysis.

Fortunately, we have downloaded and kept a copy of every report going back to the start of the COVID-19 vaccine rollout and have therefore been able to build a more detailed picture of how adverse reactions have developed over time.

The MHRA does a monthly “cut off” of data but then takes several days to make the summary report available on its website.  So at times we can be looking at information that is over a month out of date.  Given that millions were receiving vaccines each week, we are concerned that this time lag introduces additional risk as well as restricting the ability of an individual to make a truly informed decision about having the vaccine based on up to date risk information.

We are also hampered by incomplete data so have deliberately held back from drawing conclusions based on the data we have.  Instead, we aim to provide insights into what we do know so that we, and you, can ask more meaningful questions of the MHRA, the government, vaccine manufacturers – and your own healthcare providers.   

What We Do Know

What We Don't Know

* From November 2022, MHRA is issuing the data in a new format and we will be exploring whether we can glean any new insights

** From January 2023, MHRA is changing its reporting to only report on boosters administered from Autumn 2022. We will explore whether this new report will allow us to better analyse the boosters – if not historically, then at least going forward. 

Cause for Concern

As we began our first look at the week by week data, it came to our attention that Dr Tess Lawrie (MBBCh, PhD), of the Evidence-based Medicine Consultancy, was about to undertake a similar task.  We therefore reached out and agreed that we would pool our technical skills and her medical expertise to better understand and analyse the data.

An important discovery was that similar conditions had been classified in many different ways.  Dr Lawrie’s medical knowledge helped us to better group similar conditions together.  Once we did that, it became clear that there were far higher incidences of some reactions than a cursory glance of the MHRA report would suggest.

Dr Lawrie was so concerned about what she saw that she immediately presented the findings in an open letter to Dr June Raine, Chief Executive of the MHRA.  As well as presenting the findings, the letter also called for an immediate halt of the COVID-19 vaccine rollout until more detailed analysis of the Yellow Card data can be carried out. 

With the rollout continuing, Dr Lawrie sent a follow up letter in September 2021 highlighting even more concerns, particularly that the suspected deaths per million doses was 28 times higher than for the flu vaccines.   

Alas, as at January 2023, the mRNA vaccines are still being rolled out – and actively recommended by healthcare providers, government and the mainstream media – and the number of reactions and deaths attributed to them continue to rise.

Yellow Card Summary to 28th December 2022

In early January 2023, MHRA reissued the data to 23/11/22 in a new format, claiming it was the same data, however we have compared the two datasets and found an additional 83,056 reactions and 2 deaths in the reissued reports. We have made the assumption that the reissued dataset is the more accurate and therefore all charts reflect these figures going forward.
Pfizer/ BioNTech AstraZeneca Moderna Novavax Unspecified Totals
Rollout Start Date 08/12/20 04/01/21 07/04/21 03/02/22 n/a n/a
First Doses Administered 27.2 million 24.9 million 1.7 million unknown n/a 53.8 million
Second Doses Administered 25.0 million 24.2 million 1.6 million unknown n/a 50.8 million
Boosters Administered 40.6 million 40.6 million
Adverse Reactions 540,860 926,064 160,554 111 6,712 1,634,632
Deaths 872 1,348 117 2 67 2,406

New reactions this report = 6,646

New deaths this report = 42

Data Source: MHRA

(as at 23/01/23 Novavax data from 23/11/22 to 28/12/22 is not included due to technical problems at MHRA)

How The Brands Compare

Due to the small quantities currently associated with the Novavax brand, they do not show up on the pie charts


Adverse Reactions


Due to the way MHRA has been reporting booster doses without a breakdown between the brands used, there is a growing disconnect between brand dosage numbers and adverse reactions. While booster doses are shown under "Unspecified", the likelihood is that people reporting a reaction are specifying which brand they received. It is therefore increasingly difficult to draw any meaningful conclusions. We still await an explanation as to why MHRA have not been reporting booster doses by brand in the same way they report first and second doses.
We understand that from January 2023, only third and subsequent dose volumes will be reported and these will be by brand, but until we have sight of that report some time in February we will not know whether the brand totals will include doses given historically. We will update this page once we know.

Top 20 Adverse Reactions

wdt_ID Condition No of Reactions No of Deaths
1 Headache 130,211 1
2 Fatigue 93,195 1
3 Pyrexia 91,619 1
4 Chills 63,960 0
5 Nausea 57,692 0
6 Pain in extremity 46,027 2
7 Myalgia 45,585 0
8 Dizziness 43,270 0
9 Arthralgia 40,934 0
10 Pain 32,860 0

Top 20 Causes of Death

wdt_ID Condition No of Deaths
1 Death (no further information available) 620
2 Pulmonary embolism 174
3 Myocardial infarction 133
4 Cardiac arrest 109
5 Cerebrovascular accident 83
6 Cerebral haemorrhage 81
7 Sudden death 81
8 COVID-19 75
9 Thrombosis 58
10 Pneumonia 57


wdt_ID Type of Reaction (System of Care) Reactions Deaths
1 Blood disorders 29,851 26
2 Cardiac disorders 33,275 446
3 Congenital disorders 272 5
4 Ear disorders 21,316 1
5 Endocrine disorders 1,020 0
6 Eye disorders 26,570 0
7 Gastrointestinal disorders 146,908 36
8 General disorders 459,458 775
9 Hepatic disorders 951 11
10 Immune system disorders 7,196 7

Vaccine Rollout by Week

Weeks with negative doses are not our error but are where the totals contained in the MHRA reports are lower than the preceding week. We do not know if this is due to a clerical error in the preparation of the current weekly report, a correction of clerical errors made in previous reports or a correction due to errors in the past reporting of doses to the MHRA.

Further analysis coming soon

In the meantime, if you'd like to find out more about COVID-19 vaccines, the Public Health England weekly surveillance reports may prove useful:

If you'd like to find out about adverse reactions recorded in other countries, here are some useful links: