Covishield and Covaxin combo provides greater immunity: ICMR study

New Delhi: Combination of two different vaccines Covishield and Covaxin jab lift up immunity better than same dose plan, reported a new ICMR study. The study has been published in the latest issue of the Journal of Travel Medicine.

The said study further stated that the reactogenicity profile of the participants who received the two different vaccines (heterologous) showed that a combination of the two vaccines derived from different platforms turned out to be safe as well.

The researchers carried out the study with an aim of assessing the safety and immunogenicity of the heterologous prime-boost COVID-19 vaccination.

For this, the study enrolled 98 vaccine recipients from Uttar Pradesh who had completed two weeks or more after the second dose of vaccine during May to June 2021. Out of 98 participants, 18 of them received two different vaccines at an interval of six weeks. The median age of the participant is 62 years. Apart from this, two other groups, one consisting of homologous Covishield recipients at six weeks intervals and Covaxin recipients at four weeks intervals with 40 participants in each of the groups were included in the study. 

Key highlights of the study include:

• Humoral immune response and Neutralizing Antibody in the heterologous vaccination group were significantly high in neutralizing variants of concerns such as Alpha, Beta, and Delta variants.

• Local adverse event following immunization was not reported among the heterologous (Covishield and Covaxin recipients) group.

• Pyrexia and malaise with the frequency of pyrexia were the most commonly reported systemic adverse event following immunization.

• The heterologous group (Covishield and Covaxin recipients) had ~ 3-fold higher titre in comparison to the homologous group with Covishield and Covaxin groups.

• The frequency of adverse events following immunization in the heterologous group was similar to the participants in the CS/CV groups

The paper further expressed that heterologous immunization will make its way for the enlistment of improved and better protection against the variation of concern and to defeat the difficulties of shortage of a specific vaccine. It will likewise eliminate hesitancy about the vaccines to individuals that could have begun in programmatic errors.

The overall frequency of adverse events in the three different groups also established the safety of heterologous vaccination.

Regardless, multicentre randomized clinical trials should be done to decisively induce upon the likely benefits of the heterologous prime-boost immunization approach as contemplated in the current study.

Reference:

Rajni Kant, Ph.D, Gaurav Dwivedi, Ph.D, Kamran Zaman, MD, Rima R Sahay, MD, Gajanan Sapkal, Ph.D, Himanshu Kaushal, Ph.D, Dimpal A Nyayanit, Ph.D, Pragya D Yadav, Ph.D, Gururaj Deshpande, Ph.D, Rajeev Singh, Ph.D, Sandeep Chaowdhary, Ph.D, Nivedita Gupta, Ph.D, Sanjay Kumar, MCh, Priya Abraham, Ph.D, Samiran Panda, MD, DTM&H, Balram Bhargava, DM, Immunogenicity and safety of a heterologous prime-boost COVID-19 vaccine schedule: ChAdOx1 vaccine Covishield followed by BBV152 Covaxin, Journal of Travel Medicine, Volume 28, Issue 8, December 2021, taab166, https://doi.org/10.1093/jtm/taab166