A tweet on August 7 claimed that immunity function decreases after COVID-19 vaccination, resulting in various autoimmune diseases developing within two weeks.
The post lists more than a handful of illnesses such as shingles, also known as herpes zoster (HZ) (帶狀皰疹), vitiligo (白癜風), hypothyroidism (甲狀腺功能減退), sarcoidosis (肺部結節), lung cancer (肺癌), and early-stage cervical cancer (宮頸原位癌), although only vitiligo is actually an autoimmune disease.
The tweet came with two screenshots of Zhihu, a Chinese question-and-answer discussion forum, in which a number of users stated they had suffered from shingles after taking the COVID-19 vaccine. It was retweeted more than 180 times and liked over 300 times.
But the claim is not scientifically supported in any way.
Autoimmune diseases occur when the body’s defense system fails to distinguish between the body’s cells and foreign cells, according to Johns Hopkins Medicine. Medical experts say there is no scientific evidence that COVID-19 vaccination causes them, however.
Clinical virologist Siddharth Sridhar at the Department of Microbiology at the University of Hong Kong (HKU), told Annie Lab that COVID-19 vaccination causes none of the diseases mentioned in the tweet.
Dr. Vera Chan, an assistant professor at HKU’s Faculty of Medicine said, “Vaccination in general is to activate our immune system to boost immunity against pathogens. Currently, there is no scientific evidence to suggest COVID-19 vaccine behaves differently in most vaccinated individuals.”
Among the diseases listed in the claim, Chan said only vitiligo is an autoimmune disease.
“The cause of sarcoidosis is not completely known but it shares some common features with some autoimmune diseases; hypothyroidism may or may not be caused by autoimmune response; others are not autoimmune diseases,” Chan said.
Shingles is caused by the same virus that causes chickenpox. Chan said the re-emergence of shingles can be triggered by many factors.
“The appearance of [shingles] is more related to the underlying health problems and not directly caused by COVID-19 vaccination,” Chan explained, referring to the findings of a study published by the Oxford University Press on April 13, 2021.
The study looked into the safety of COVID-19 vaccines for patients with autoimmune inflammatory rheumatic diseases (AIIRD). It reported six patients out of 491 (1.2%) had shingles after the vaccinations, as opposed to none among the control group.
The study, however, stated specifically that it was not designed to determine the link between vaccination and shingles, but to “raise awareness to a potential causal link between COVID-19 vaccination as a trigger of HZ reactivation in relatively young patients with stable AIIRD.”
Sridhar said shingles is a common viral infection caused by the reactivation of varicella zoster virus.
“Although there are reports of zoster emergence after COVID-19 vaccination, there is no convincing evidence to suggest the two are linked,” he said.
He stressed that it is possible that the two events are coincidentally occurring together.
A similar claim that falsely states herpes and shingles can be caused by COVID-19 vaccination has been debunked by the Associated Press.