New Delhi: The administration of COVAXIN booster dose will enhance the vaccine effectiveness against the Delta variant infection and give protection against the Omicron variants BA.1.1 and BA.2, said the Indian Council of Medical Research (ICMR)-NIV.
The National Institute of Virology conducted a study on hamsters to arrive at the conclusion.
The researchers compared the efficacy of Covaxin after the second and third doses against the Delta variant that hit India during the second wave, and also studied its efficacy against the Omicron variants in a Syrian hamster model.
According to the paper, researchers studied the antibody response, clinical observations, viral load reduction and lung disease severity.
“Protective response in terms of the reduction in lung viral load and lung lesions were observed in both the second as well as third dose of Covaxin immunised group when compared to placebo group following the Delta variant challenge. In spite of the comparable neutralising antibody response against the homologous vaccine strain in both the Dose 2 and Dose 3, considerable reduction in the lung disease severity was observed in the third dose immunised group post Delta variant challenge, indicating the involvement of cell mediated immune response also in protection,” the paper stated.
“In the vaccine efficacy study against the Omicron variants BA.1 and BA.2, lesser virus shedding, lung viral load and lung disease severity were observed in the immunised groups in comparison to the placebo groups,” it further said.
