Nearly one-third of the individuals who received Bharat Biotech's anti-Covid vaccine Covaxin reported 'adverse events of special interest,' or AESI, according to a one-year follow up study conducted by a team of researchers at BHU.

Nearly 50 per cent of 926 study participants in the study complained of infections during the follow-up period, predominated by viral upper respiratory tract infections.

Serious AESI, which included stroke and Guillain-Barre syndrome, were reported in one per cent of individuals, the study, which looked at long-term safety of the BBV152 vaccine in adolescents and adults, claimed.

Published in the journal Springer Nature, the study comes in the wake of UK pharmaceutical giant AstraZeneca admitting its Covid vaccine can cause rare side-effects of blood clotting and lowering of platelet count in UK court.

"Close to one third of the individuals developed AESIs. 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," the study, conducted from January 2022 to August 2023, said.

The study involved 635 adolescents and 291 adults, who received the BBV152 vaccine. The participants were interviewed telephonically about long-term adverse events of special interest after 1 year of vaccination.

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 Four deaths (three female individuals, one male individual) were reported in adults, the study added.

All four had diabetes, while hypertension in three, and a history of pre-vaccination COVID-19 was present in two of them.

Stroke was the main contributor in two deaths and one fatality was due to post-COVID-19 rhinocerebral mucormycosis, which supposedly disseminated after vaccination as reported by the caregivers.

The fourth death happened in a woman with multiple episodes of unconsciousness post-vaccination, the etiology of which remained unidentified till death. In the absence of a definite causality association, no conclusions can be drawn from these events.

With the majority of AESIs persisting for a significant period, extended surveillance of COVID-19-vaccinated individuals is warranted to understand the course and outcomes of late-onset AESIs, the study underlined.

Serious AESIs might not be uncommon and necessitate enhanced awareness and larger studies to understand the incidence of immunemediated phenomena post-COVID-19 vaccination .

Female individuals, adolescents with pre-vaccination COVID-19, those with co-morbidities, and those with post-vaccination typhoid had respectively 1.6, 2, 2.7, and 3.2 times higher odds of persistent AESIs.

Adults with co-morbidities had more than two times higher odds of AESIs and persistent AESIs, the study stated.

Adults receiving three doses and those receiving one dose of BBV152 were respectively at four and two times higher risk of AESIs compared with adults receiving two doses of the Covaxin, the study said.

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