Neurological adverse events are very rare after COVID-19 vaccination and less frequent than after SARS-CoV-2 infection

REVIEW

On 10 May 2023, a tweet from an account called Leading Report claimed that “COVID vaccines could be causing ‘long-term brain damage’”. The claim was based on a review published by Hosseini and Askari in the European Journal of Medical Research on 25 February 2023 that evaluated the potential effects of COVID-19 vaccines on the nervous system.

Although the tweet was deleted a few days later, it still gathered more than 2.4 million views and 2,800 retweets, including a particularly viral retweet by Twitter user Catturd2, who has 1.7 million followers. This retweet alone accumulated 1.8 million additional views and 9,000 retweets, spreading on Instagram as well.

Catturd2 became popular thanks to its frequent interactions with Twitter owner Elon Musk and former U.S. president Donald Trump and has propagated political and COVID-19 misinformation on multiple occasions. In addition, Catturd2 also participated in a networked harassment campaign targeting U.S. Representative Alexandria Ocasio-Cortez, according to an investigation by the digital research platform Media Manipulation Casebook.

The same review that the tweet cited was also picked up in a Substack article by Colleen Huber, a naturopath who promotes unproven cancer cures and regularly spreads COVID-19 misinformation. Huber’s article claimed that there were ways in which COVID-19 vaccines supposedly enter the brain and damage neurons, presenting Hosseini and Askari’s review as evidence of post-vaccination “neurological injuries”.

However, the review doesn’t provide such evidence, and the claim that COVID-19 vaccines cause or increase the risk of neurological problems based solely on this review is unsupported, as we will explain below.

The review by Hosseini and Askari didn’t show that COVID-19 caused neurological problems

In their review, Hosseini and Askari evaluated neurological events described in the scientific literature following vaccination with an mRNA (Moderna and Pfizer-BioNTech), viral vector (AstraZeneca, Johnson & Johnson, and Sputnik), or inactivated virus (Sinovac, Sinopharm, and Covaxin) vaccine between 2020 and February 2022.

Based on the results from these studies, the review concluded that the most common neurological adverse events reported following COVID-19 vaccination were mild and transient, such as headache, fatigue, and joint pain. Less common symptoms included tremors, tinnitus, and a reactivation of the virus that causes chickenpox in a person who had the disease, and that can cause nerve pain and a broad range of neurological complications. Finally, serious neurological adverse events included venous sinus thrombosis—a