A new study has come to the fore regarding the Kovishield vaccine to be used to protect against the Corona Pandemic. This Lancet study states that the protection provided by Covishield against the delta variant decreases after 3 months. This vaccine has been developed by AstraZeneca while it is produced by the Serum Institute of India. Covaxin as well as the Covishield vaccine have been used extensively in India.
However, the Lancet had claimed in its previous study that Covishield is very effective against the delta variant. It provides 63 percent protection against fully vaccinated people, while its effectiveness against moderate to severe disease is 81 percent.
Lancet’s new study
In the new study, researchers analyzed the association between exposure to two doses of the Covishield vaccine in severe COVID-19 cases in Scotland and Brazil. In a paper published in the journal about this study, the researcher said that we found that the protection of the ChAdOx1 nCoV-19 vaccine against Covid-19 was reduced in both Scotland and Brazil with respect to hospitalization and death, the second of the vaccine. This became apparent within 3 months of taking the dosage. He said that those who have taken the Kovishield vaccine should think about taking the third dose as a booster dose.
Professor Srinivas Katikireddy of the University of Glasgow said that in this study 19,72,454 people took both doses of the vaccine in Scotland, while 4,25,58,839 people who got the vaccine in Brazil were included. This study was started in Scotland on 19 May 2021 and started in Brazil on 18 January 2021 and lasted till 25 October 2021.
In countries where the level of vaccine coverage was high, the rate of infection and severe cases of Covid-19 increased. However, this could be due to new variants which notably include Delta (B.1.617.2) and Gamma. It is also possible that the effectiveness of the vaccine is decreasing over time. At the same time, researchers have not said anything in this study regarding the Omicron variant that surfaced in November.
The Covishield vaccine has been used in large numbers in India. Apart from this, this vaccine has also been used in other countries of the world. Because of the economic rate and ease of storage, the Kovidhield vaccine has been widely used, especially in low-income countries and middle-income countries.
