A team of researchers at BHU in a one-year follow-up study found out that nearly one-third of 926 individuals who received Bharat Biotech's anti-Covid vaccine Covaxin reported 'adverse events of special interest,' or AESI. An AESI is an event that occurs in some people post immunisation that has the potential to be causally associated with a vaccine product.

Serious AESI, including stroke and Guillain-Barre syndrome, was reported in around one per cent of individuals as per the study. New-onset skin and subcutaneous disorders, general disorders, and nervous system disorders were the three most common disorders observed in adolescents after receiving the vaccine. Guillain-Barre syndrome is an autoimmune disorder that causes weakness in nerves in the arms and legs. An ischemic stroke occurs when the blood supply to part of the brain is blocked or reduced.

The study published in the Journal of Springer Nature looked at the long-term safety of the BBV152 (Covaxin) vaccine in adolescents and adults.

The study that was conducted from January 2022 to August 2023 mentioned that nearly 50 per cent of the sample size complained of infections during the follow-up period, predominated by viral upper respiratory tract infections.

However, Bharat Biotech in a statement in response to the study, said, "several studies have been executed on the safety of Covaxin, and published in peer-reviewed journals, demonstrating an excellent safety track record". The study involved 635 adolescents and 291 adults, who received the BBV152 vaccine.

Common AESIs reported in adults and adolescents

• New-onset skin and subcutaneous disorders (10.5 per cent), general disorders (10.2 per cent), and nervous system disorders (4.7 per cent) were the common AESIs in adolescents.
• General disorders (8.9), musculoskeletal disorders (5.8 per cent), and nervous system disorders (5.5 per cent) were the common AESIs in adults.
• Menstrual abnormalities were noticed in 4.6 per cent of female participants.
• Ocular abnormalities and hypothyroidism were observed in 2.7 per cent and 0.6 per cent of participants.

Long-term side effects of Covaxin: Should people be concerned?

"The creation of Covid-19 vaccines, such as Bharat Biotech's Covaxin, was essential to contain the pandemic. To guarantee patient safety and successfully address issues, it is crucial to monitor and comprehend the long-term adverse effects, just as with any medical operation," says Dr Vanita Arora, Senior Consultant Cardiac Electrophysiologist & Interventional Cardiologist at Apollo Hospital, Delhi.

Unfavourable events of particular interest (AESI)

Research from Banaras Hindu University and other recent studies have shown that approximately one-third of subjects experienced AESI a year after using Covaxin. The most frequent of these occurrences, which varied in severity, were viral upper respiratory tract infections. Reports of severe AESI, like stroke and Guillain-Barré syndrome, were more worrisome.

Possible side effects of Covaxin

Dr Arora shares the possible side effects of Covaxin and whether those who got jabbed needed to worry:

Stroke

Significant concerns are raised by strokes described as AESI, particularly in patients with cardiovascular risk factors. Although the exact pathophysiological processes relating vaccinations to stroke remain unclear, it is possible that they entail an immune-mediated process that aggravates underlying vascular problems. Patients should be especially careful if they have a history of atrial fibrillation, diabetes, or hypertension. It is advised to keep cardiovascular risk factors under control and to undergo routine follow-ups. It is crucial to consider the danger in its proper context, though, as the risk of severe consequences from Covid-19 alone is still much higher than the rate of stroke following immunisation.

GBS, or Guillain-Barré Syndrome

Although the incidence rate of GBS post-Covaxin is minimal, it is worth emphasising that its prevalence is alarming. It is important to educate patients about the early signs of GBS, which include tingling feelings and weakness in the muscles so that they can seek medical assistance as soon as they appear.

Effects on patients who already have health issues

"Following Covaxin treatment, adults with pre-existing medical issues seem to be more vulnerable to AESI. Patients suffering from long-term conditions like diabetes, heart disease, and autoimmune disorders should pay special attention to this. These people should keep up their routine health monitoring and notify their healthcare professional right if they experience any unexpected symptoms," says Dr Arora.

Benefits vs side effects

"While these adverse effects are important to consider, it's also important to weigh them against the advantages of vaccination. Hospitalisations, fatalities, and a reduction in the severity of Covid-19 infections have all been successfully avoided with the use of Covaxin. Significant Covid-19 consequences, such as chronic heart problems, are frequently more likely to occur than significant AESI, which is a relatively low risk," adds the expert.

"Ideally a vaccine should not have any side effects, but unfortunately we don’t have an ideal vaccine to date. Vaccine-related adverse events usually happen rarely and get better with paracetamol and taking fluids. Nonetheless, the advantages of vaccination far surpass the risks by shielding us from severe health complications. AESIs, known as Adverse Events of Special Interest have been raised with certain patients who had Covaxin. If we analyse the effect of Covaxin on fight against COVID and compare them to certain adverse events in few patients, benefits clearly outweigh risk. It's therefore important not to fret or lose hope about these occurrences," says Dr Arunesh Kumar Head & Senior Consultant - Pulmonology and Respiratory Medicine, Paras Health.

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