Batch-dependent safety of Pfizer batches

Some batches had many more adverse reactions reported than others

I have now recorded two videos on this interesting and concerning paper from Danish research.

Batch-dependent safety of the BNT162b2 mRNA COVID-19 vaccine

https://onlinelibrary.wiley.com/doi/10.1111/eci.13998

This is my video discussing the paper directly.

This second video is a detailed discussion with the lead author, Dr.Vibeke Manniche.

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.

F I G U R E 1 Numbers of suspected adverse events (SAEs) after BNT612b2 mRNA vaccination in Denmark (27 December 2020–11 January 2022) according to the number of doses per vaccine batch.

The top blue dot represents an adverse reaction rate of 1 for every 20 vaccines given.

The top green dot represents an adverse reaction rate of 1 for every 1,000 does of vaccine given.

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 (hospitalisation or prolongation of existing hospitalisation, life-threatening illness, permanent disability or congenital malformation) or SAE-related deaths respectively.

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 deaths

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