Nearly a third of participants who took Covaxin, the COVID-19 vaccine made by Bharat Biotech Ltd, reported adverse events of special interest (AESI), with women and those with allergies at higher risk, says a
new study published on SpringerLink. The study conducted by Sankha Shubhra Chakrabarti and his team at Banaras Hindu University found that women, adolescents and those with pre-vaccination COVID-19 or comorbidities had higher odds of AESIs.
The majority of AESIs persisted at the one-year follow-up, the study says, adding, "Common AESIs included viral upper respiratory tract infections, skin disorders, and nervous system issues. Serious AESIs like stroke and Guillain-Barre Syndrome were rare but reported."
The observational study was conducted from January 2022 to August 2023. Adolescents and adults receiving the BBV152 vaccine (Covaxin) were interviewed telephonically about long-term AESIs after a year of vaccination. The study also identified risk factors of AESIs and AESIs that were persistent for at least one month.
Out of 1,024 individuals enrolled, the research team contacted 635 adolescents and 291 adults during the one-year follow-up. It says 304 (47.9%) adolescents and 124 (42.6%) adults reported viral upper respiratory tract infections during this period.
It says, "New-onset skin and subcutaneous disorders (10.5%), general disorders (10.2%), and nervous system disorders (4.7%) were the common AESIs in adolescents. General disorders (8.9%), musculoskeletal disorders (5.8%), and nervous system disorders (5.5%) were the common AESIs in adults. Menstrual abnormalities were noticed in 4.6% of female participants. Ocular abnormalities and hypothyroidism were observed in 2.7% and 0.6% of participants, respectively. Among serious AESIs (1%), stroke and Guillain-Barre syndrome were identified in 0.3% and 0.1% of participants, respectively."
"Among adolescents, female individuals, those with a history of allergy and post-vaccination typhoid were respectively at 1.6, 2.8, and 2.8 times higher risk of AESIs. The majority of the AESIs persisted at the one-year follow-up. Female individuals, adolescents with pre-vaccination COVID-19, those with comorbidities, and those with post-vaccination typhoid had respectively 1.6, 2, 2.7, and 3.2 times higher odds of persistent AESIs. Adults with comorbidities had more than two times higher odds of AESIs and persistent AESIs," the study shows.
According to the research note, the patterns of AESIs developing after BBV152 (Covaxin) differed from those reported with other COVID-19 vaccines, as well as between adolescents and adults.
It says, "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. Serious AESIs might not be uncommon and necessitate enhanced awareness and larger studies to understand the incidence of immune-mediated phenomena post-COVID-19 vaccination. The relationship of AESIs with sex, comorbidities, pre-vaccination Covid-19, and non-Covid illnesses should be explored in future studies."
Bharat Biotech, however, says for such a study in safety to be effective and informative and to avoid investigator bias, the AESI safety profile of the subjects prior to participation in the study has to be kept in mind.
“Comparison of the safety profile of non-vaccinated subjects during the course of the study, comparison of the safety profile of subjects who received other vaccines during the course of the study, and all study participants should be followed during the course of the study, instead of only a subset,” it added.
Covaxin, India's indigenous COVID-19 vaccine by Bharat Biotech, is developed in collaboration with the Indian Council of Medical Research (ICMR) and the National Institute of Virology (NIV). "The vaccine is developed using whole-virion inactivated vero cell-derived platform technology. Inactivated vaccines do not replicate and are, therefore, unlikely to revert and cause pathological effects. They contain dead virus, incapable of infecting people but still able to instruct the immune system to mount a defensive reaction against an infection,"
Bharat Biotech says.
The company claims that Covaxin demonstrated 77.8% vaccine efficacy against symptomatic COVID-19 disease through the evaluation of 130 confirmed cases, with 24 observed in the vaccine group versus 106 in the placebo group. "The efficacy against severe symptomatic COVID-19 disease is shown to be 93.4%. The efficacy data demonstrates 63.6% protection against asymptomatic COVID-19."
