HYDERABAD: Researchers, including those from Kurnool medical college, have said that the novel coronavirus variant, N440K, can cause reinfection.
According to them, this variant can escape the immune system and can cause reinfection in patients already recovered from Covid-19.
The researchers studied a case in Kurnool, which they said was the second case of Covid-19 reinfection in India caused by the variant N440K, one of the most rogue mutants of the pandemic virus. The study was published on pre-print research server OSF.
Earlier, researchers from CCMB and Apollo hospitals in Hyderabad recorded two cases of Covid-19 reinfection in the city, but these were not related to N440K. The city scientists had said their work had shown that Covid-19 can cause reinfection irrespective of the virus undergoing mutation in the spike protein or not.
Researchers from Kurnool Medical College, Kurnool, Institute of Genomics and Integrative Biology, Delhi, and Academy of Scientific and Innovative Research, Ghaziabad, have found that N440K has a high prevalence of over 33% in Andhra Pradesh.
A 44-year-old public service employee was diagnosed positive for Covid-19 on July 25, 2020. He tested negative on August 2, 2020. However, he tested positive again on September 10, 2020, during routine surveillance. He showed symptoms like fever, cough, and malaise.
The research team comprising Pallavali Roja Rani, Mohammed Imran, Juturu Vijaya Lakshmi, Bani Jolly, Abhinav Jain, Avileli Surekha, Vigneshwar Senthivel, Pulala Chandrasekhar, Mohit Kumar Divakar, Damam Srinivasulu, Rahul C Bhoyar, PR Vanaja, Vinod Scaria, and Sridhar Sivasubbu found 15 and 17 genetic variants in the genomes from the two episodes of infection in the public service employee, respectively. Of them 14 variants were common between the two episodes.
“A close comparison of the genetic variants with a compendium of immune escape variants revealed a Spike N440K variant in the genomes isolated from both episodes of infection,” the study revealed. Incidentally, this variant was also found in a case of reinfection previously reported by the team in a healthcare worker from North India.
Analysis shows that genomes isolated from the two episodes fell under two distinct clusters of genomes, closely related with other genomes from Andhra Pradesh. The close resemblance of the genome isolates from the two episodes of infection yet the presence of distinct variants in the two genomes suggests that the patient acquired both infections from the same location in Andhra Pradesh at two different time points.
Recent studies exploring the role of novel coronavirus genetic variations in escaping immune response has shed light on the possible mechanisms of the pathogen to evade antibody response and immune reactions. The N440K variant has been reported to be resistant, the researchers reported.
The high prevalence of N440K in India along with the findings presented in the study highlight the importance of analysing the potential impact of the variant and additional host factors on reinfections and immune evasion, the researchers added.