ntroduction

A chronic post-vaccination syndrome (PVS) after covid-19 vaccination has been reported but has yet to be well characterized.

A chronic syndrome with symptoms that begin soon after vaccination

Methods

People who joined, May 2022 to July 2023

N = 241 individuals, (211 from the US)

aged 18 and older,

who self-reported PVS after covid-19 vaccination,

Deep immune profiling is used for some individuals

Results

Median age of participants, 46 years

Among participants with PVS

127 (55%) had received BNT162b2 [Pfizer-BioNTech]

86 (37%) received the mRNA-1273 [Moderna]

Time from index vaccination to symptom onset

Median time, 3 days (IQR: 1 day to 8 days).

Time from vaccination to symptom survey completion

595 days (IQR: 417 to 661 days)

Median Euro-QoL visual analogue scale score was 50 (IQR: 39 to 70).

The five most common symptoms

Exercise intolerance (71%)

Excessive fatigue (69%)

Numbness (63%)

Brain fog (63...