New York, June 20: While Alpha and Beta COVID variants are associated with higher transmission, patients with these variants show no evidence of higher viral loads in their upper respiratory tracts compared to the control group, a study led by Johns Hopkins School of Medicine study found on Sunday.
The emergence and higher transmission of the evolving variants of SARS-CoV-2, the virus that causes Covid-19, has been concerning. The researchers investigated Alpa (B117), the variant first identified in the UK, and Beta (B1351), first identified in South Africa, to evaluate if patients showed higher viral loads, and consequently increased shedding and transmissibility.
“The reason why these variants show higher transmissibility is not yet clear,” said Adannaya Amadi, lead author.
“However, our findings did show that the patients infected with these variants are less likely to be asymptomatic compared to the control group. Although those infected with the variants were not at higher risk for death or intensive care admission, they were more likely to be hospitalised,” Amadi added. The research will be presented at the World Microbe Forum, taking place online from June 20 to 24.
Variants were identified using whole genome sequencing. Researchers used a large cohort of samples to show that the UK variant constituted 75 per cent of the circulating viruses by April 2021.
The researchers compared 134 variant samples to 126 control samples and with access to the patients’ clinical information, were able to correlate the genomics data with the clinical disease and outcomes.
All samples underwent additional testing to determine their viral load. The information was associated with the stage of the disease by looking at the days after the start of symptoms which added clarity in comparing viral shedding between groups.
Immune response following a coronavirus infection can vary between individuals and may not be enough to fight Alpha, and Beta variant of Covid-19, finds another study reinforcing the need for vaccination.
The study found that people who produced a weak immune response signature, obtained at one and six months post infection, failed to show any neutralising antibodies against the Alpha variant, with none mounting a neutralising antibody response against the Beta variant.
The preprint study was led by University of Oxford, in collaboration with the Universities of Liverpool, Sheffield, Newcastle and Birmingham, suggests that whether it is symptomatic or asymptomatic infection, it does not necessarily protect people long-term from Covid-19, particularly against new Variants of Concern.
“Our study is one of the most comprehensive accounts of the immune response following Covid-19 in both symptomatic and asymptomatic individuals. It is very important that we all get the Covid vaccine when offered even if you think you may have previously had Covid-19,” said Christina Dold, from the University of Oxford. (IANS)
