Batch-dependent safety of the BNT162b2 mRNA COVID-19 vaccine
71% of the suspected adverse reactions occurred in 4.2% of the vaccine batches
Numbers of suspected adverse events (SAEs),
after BNT612b2 mRNA vaccination in Denmark.
27 December 2020–11 January 2022, (population 5.8 million)
(According to the number of doses per vaccine batch)
Each dot represents a single vaccine batch.
By 11 November 2022 (European area)
701 million doses of Pfizer given
971,021 reports of suspected adverse effects (SAEs)
Clinical data on individual vaccine batch levels have not been reported
(batch-dependent variation in the clinical efficacy and safety of authorized vaccines would appear to be highly unlikely)
We therefore examined rates of SAEs between different BNT162b2 vaccine batches administered in Denmark
Data on all SAE cases, Danish Medical Agency (DKMA)
SAE seriousness was classified as non-serious, serious
(hospitalization or prolongation of existing hospitalization, life-threatening illness, permanent disability or congenital malformation) or SAE-related d****
Anonymized data
SAEs were counted on a batch level by linking individual SAEs to the batch label(s) of BNT162b dose(s)
10,793,766 doses administered
4,026,575 persons
52 different BNT162b2 vaccine batches
(2,340–814,320 doses per batch)
43,496 SAEs were registered in 13,635 persons
61,847 batch-identifiable SAEs,
of which 14,509 (23.5%) were classified as severe,
579 (0.9%) were SAE-related d*****
Unexpectedly
Rates of SAEs per 1000 doses varied considerably between vaccine batches
From 1 SAE per 20 doses given to I in many thousands to zero
Variabilities
Vaccine manufacturing
Storage
Transportation
Clinical handling and control
Administration technique