Some of the most common chronic symptoms of PVS include exercise intolerance, excessive fatigue, brain fog, insomnia, and dizziness. They develop shortly after vaccination, within a day or two, can become more severe in the days that follow, and persist over time. More studies are needed to understand the prevalence of PVS.
“It’s clear that some individuals are experiencing significant challenges after vaccination. Our responsibility as scientists and clinicians is to listen to their experiences, rigorously investigate the underlying causes, and seek ways to help,” said Harlan Krumholz, the Harold H. Hines, Jr. Professor of Medicine (Cardiology) at YSM and co-senior author of the study.
Data for the study came from Yale’s Listen to Immune, Symptom, and Treatment Experiences Now (LISTEN) Study, through which researchers aim to better understand long COVID and PVS. For the new study, researchers included data from 42 LISTEN participants who reported symptoms of PVS and 22 individuals who did not report any PVS symptoms after receiving a COVID-19 vaccination.
From participants’ blood samples, the researchers looked for immune features that were different between the two groups. They found several differences in immune cell populations; those with PVS had lower levels of effector CD4+ T cells and higher levels of TNF-alpha+ CD8 T cells — both are types of white blood cells — among other differences.
There were also differences in the levels of antibodies that the body uses to target SARS-CoV-2. Participants with PVS who had never contracted COVID-19 had lower levels of antibodies against the SARS-CoV-2 spike protein than control participants, likely because they tended to have fewer vaccine doses than individuals without PVS. Fewer vaccine doses and no viral infection means the body’s immune system has had little opportunity to develop a defense to the virus, said the researchers.