Research surrounding COVID-19 variants, treatments, and aftereffects continued for over three years after the first case was reported. Researchers and medical professionals continue to learn about SARS-CoV-2, using their findings to increase prevention of and protection against COVID-19 and its aftereffects.
Most people who become infected with COVID-19 experience symptoms. However, approximately 20% of people who are diagnosed remain asymptomatic.1 Researchers hypothesized that a human leukocyte antigen (HLA) loci variant may be responsible for asymptomatic COVID-19 cases. A cohort of unvaccinated people with a genetic variant, HLA-B*15:01, with positive COVID-19 diagnoses participated in the study. The researchers studied to see if there was an association between five HLA loci and asymptomatic infection. The results found an association between HLA-B*15:01 and people with two copies of the genetic variant – passed down by their mother and father – being asymptomatic.
The findings suggest a connection between pre-existing T-cell immunity. The researchers discovered that T-cells from pre-COVID-19 containing HLA-B*15:01 were sensitive to the “immunodominant SARS-CoV-2-S- derived peptide NQKLIANQF.”1 The T-cell findings showed that people with HLA-B*15:01 had pre-existing immunity.
Researchers used the participants’ data to assess whether nongenetic factors changed the participants’ likelihood of having asymptomatic symptoms. They found that nongenetic factors did not affect whether a person would be asymptomatic.
COVID-19 continues to create subvariants. Each subvariant carries with it the risk of increasing infection and side effect rates. The Centers for Disease Control and Prevention (CDC) updates their COVID-19 variant projection every two weeks. The three prevalent variants2 are EG.5 (nicknamed Eris), FL.1.5.1 (nicknamed Fornax), and BA.2.86 (nicknamed Pirola).
Two of the prevalent COVID-19 variants descend from Omicron’s subvariant XBB.
The World Health Organization (WHO) declared EG.5 a variant of interest. According to the CDC’s variant projection, EG.5 is the dominant COVID-19 variant in the United States. The variant is estimated to be 20.6% of new infections.
Following behind EG.5, FL.1.5.1 comprises 13.3% of newly reported COVID-19 cases.2 The rates of reported cases nearly doubled from the previous week.
EG.5 and FL.1.5.1 derive from XBB variant descendants with a mutation. The mutation, F456L, may be why the variants quickly spread.
The difference between BA.2.86, EG.5, and FL.1.5.1 is its variant ancestor, BA.2. BA.2.863 is a highly mutated strain of COVID-19. While still small, the CDC continues to track it.
The symptoms of the variants remain like previous COVID-19 strains.