According to the study undertaken by renowned medical institutions, the individuals who have earlier been infected and have received their first dose of the vaccine have higher protection against the Delta Variant of the COVID-19 infection.
The study was conducted by the Indian Council of Medical Research (ICMR) Department of Neurosurgery, National Institute of Virology and Command Hospital (Southern Command) and Pune’s Armed Forces Medical College.
“Prior vaccination results in less severe disease against subsequent infection provide evidence that both humoral and cellular immune response plays an important role in protection,” the study said.
The study was evaluated based on the immune system of 5 different categories of individuals –
1. Person who received one shot of the vaccine
2. Person who received two shots of the vaccine
3. Covid recovered patients who have got only one jab
4. Covid recovered patients who got both the jabs
5. Breakthrough cases, which mean infection after one or two doses of vaccination
As per the study, “the lineage further mutated to generate sub-lineages B.1.617.1 (Kappa), B.1.617.2 (Delta) and B.1.617.3. Apparently, the Delta variant has slowly dominated the other variants. With this, the World Health Organisation has described this sub-lineage as a variant of concern”. The covid-19 vaccine was initially designed to fight against the first variant of the virus. However, the virus has now mutated itself and it can bring down the efficacy rate of the vaccine.
“The worldwide endeavour of scientists to create a safe and effective COVID19 vaccine has resulted in the availability of 18 vaccines, which have received Emergency Use Authorization. The vaccines available against SARS-CoV-2, have shown efficacy ranging from 51 per cent to 94 per cent against the original strain D614G in phase 3 clinical trials,” the study claimed.
“Immune response to SARS-CoV-2 infection involves innate immune activation and antigen-specific responses of B and T cells. Particularly, the questions about the immune escape of, newly emerging VOCs in vaccinated individuals are still being explored. For example, the efficacy of AZD1222, which was reported to be 70 per cent in the UK and Brazil, only reached 22 per cent in South Africa,” it added.