Rare Side Effects of COVID-19 Vaccination

 The World Health Organization (WHO) declared the novel human coronavirus COVID-19 a global pandemic on the 11th of March 2020. The disease came like a whirlwind and took the world by an unimaginable surprise. The cry for a cure or vaccine seemed farfetched. However, hope came on the horizon with the development and approval of the Pfizer, Moderna, and AstraZeneca vaccines. Research has proven that there are some rare but serious post-vaccination events that need serious attention, such as Vaccine-Induced Thrombocytopenia and Thrombosis (VITT). 

Thrombosis occurs when a blood clot forms either in an artery or vein. The blood clot if not treated can lead to damage to a portion(s) of the brain. On the other hand, Thrombocytopenia is a condition that occurs when the platelet count in the blood becomes too low. Platelets are tiny blood cells that are made in the bone marrow from larger cells. Platelets stick together when one is injured to form a plug (blood clot) to prevent further bleeding. When platelets are very low, a person can bleed to death. Bilotta et al., (2021), carried out a systematic review and exploratory analysis of articles on Covid-19 vaccine-related thrombosis. They selected 10 out of 50 articles on the topic from February 1 to May 5, 2021, and performed a descriptive analysis of adverse events caused by the Pfizer, Moderna, and AstraZeneca vaccines. They reported that, generally, symptoms appeared around the third day for the Pfizer and Moderna vaccines, while for AstraZeneca, symptoms appeared around the ninth day, and headache was the most common symptom. The platelet count was below the lower limit of the normal range. 

Furthermore, all patients except one were positive for PF4 antibodies (a test performed to detect antibodies that develop in some people who have been treated with heparin). The research found that the cerebral venous sinus of the brain was the most affected site. Death was the most common outcome in all studies, except for one study in which most of the patients survived.

Similarly, in a case report and narrative review by Ali et al., (2023), a case of VITT in a young female who presented with persistent headaches and fevers followed by unequal pupil sizes and right-sided paralysis. Radiological and laboratory investigations revealed a blood clot in the left transverse and superior sagittal sinuses of the brain, and she was diagnosed with VITT. The study concluded that “although the risk of VITT following the COVID-19 vaccine appears to be low, early diagnosis and management can be lifesaving”. 

In conclusion, the common takeaway from these studies is that headaches and fevers following COVID-19 vaccination within the first two weeks of vaccination should be taken seriously to rule out VITT. There is sufficient evidence to show that COVID-19 vaccination brings along with it, some adverse events that are worthy of note as they can be very life-threatening and fatal. There is a need for further studies or improved vaccines that would eliminate these deadly but rare adverse events. 

Dr Stella Nneoma Nwosu is a Medical Doctor and a Public Health expert at Emory University, Atlanta Georgia