Over four years have passed since the first SARS-CoV-2 outbreak occurred, and scientific advancements have reshaped our understanding of immunity and virus dynamics. Initially, the rapid development and deployment of vaccines were hailed as groundbreaking achievements, with mRNA technology leading the charge in eliciting robust antibody responses. However, the emergence of variants like Delta and Omicron presented new challenges, revealing the need for continuous monitoring and adaptation of vaccines. Recent innovations have focused on improving the durability and breadth of antibody responses, with updated booster formulations designed to tackle evolving viral mutations.
Research
Earlier this month, Movsisyan et al. tracked the evolution of anti-SARS-CoV-2 antibodies and long-term humoral immunity within 2 years after COVID-19 infection in convalescent patients. Their findings revealed sustained seropositivity rates for both anti-SARS-CoV-2 (N) and (S), as well as distinct dynamics in the long-term antibody responses, with anti-SARS-CoV-2 (N) levels displayed remarkable persistence and anti-SARS-CoV-2 (S) antibodies exhibited a progressive incline. In addition, demographic and clinical characteristics like Rh status, age, gender, and disease severity, were found to be significant predictors of antibody production and kinetics.
DOI:10.1038/s41598-024-64414-9
Long COVID occurs when patients whose acute viral infection became a long-term condition with various symptoms, including fatigue, shortness of breath, and memory or cognitive dysfunction. There is still debate in the cause, with suggestions including:
Persistence of SARS-CoV-2 in the body
Tiny blood clots that block blood vessels and limit oxygen exchange in a person’s body
The autoantibody hypothesis
Chen et al. tested this autoantibody hypothesis by passively transferring total IgG from Long COVID patients to mice, and discovered that it induced symptomology in mice. This replication of disease symptoms underscores IgG’s causative role in Long COVID pathogenesis. Therefore, their study proposes a murine model which could be used as a tool for screening and developing targeted therapeutics.
IgG from Long COVID patients induces sensory hypersensitivity in mice. DOI:10.1101/2024.05.30.596590
Therapeutics
Recently, researchers developed a recombinant human monoclonal antibody from a convalescent individual after SARS-CoV-2 Omicron infection. The antibody is named 1301B7 and demonstrated broad specificity for SARS-CoV-2 JN.1 and other variants. As a receptor binding domain antibody, it targets part of the spike protein responsible for enabling the virus to bind and enter a cell. As of now, a provisional invention patent for 1301B7 has been filed and is currently in the process of licensing for commercialization.
RBD-ACE2 stabilized fusion protein for isolation of B cells. DOI:10.1101/2024.04.27.591446
Diagnostics
Meanwhile, many studies on public health responses are also shedding light on real-world consequences. A paper by Ngomtcho et al. took a look at SARS-CoV-2 infection and antibodies amongst health personnel during the outbreak in Cameroon. Their results showed that active infections were within the range of pandemic control (<10%), but two-fifths of participants have had contact with the virus. Thus, there is need of vaccine to achieve protectiveness, and optimal response also requires capacity building to improve the health system when challenged by a future pandemic.
