This study shows some very promising results of new antibody therapies against SARS-CoV2 infection. Here, we will break down this study so it’s a little easier to digest. Let’s start with antibodies:
– Antibodies are pivotal components of the immune system, playing a crucial role in neutralizing pathogens and preventing infections. In the context of SARS-CoV2, antibodies have emerged as a promising therapeutic strategy to combat COVID-19. Let’s go over the basic types of antibodies used against SARS-CoV2, their mechanisms, development processes, real-world applications, challenges, and future directions.
Types of Antibodies
1. Monoclonal Antibodies (mAbs)
– mAbs are produced by a single clone of B cells, targeting specific viral antigens. While effective against specific variants, they may be less effective if the virus mutates, as observed during the COVID-19 pandemic.
2. Polyclonal Antibodies
– These antibodies originate from multiple clones, offering broader coverage across different viral variants. They can enhance immunity by targeting various components of the virus.
3. Bispecific Antibodies
– Combining two antigen-specificities in a single antibody enhances neutralization and reduces mutational escape. Studies show that bispecific cocktails improve efficacy against multiple variants.
4. Antibody Cocktails
– Combinations of mAbs, polyclonal antibodies, or bispecific antibodies can provide potent and broad-spectrum protection, as demonstrated by real-world case studies in countries like South Africa.
Development Through High-Throughput Methods
High-throughput methods, such as single-cell sequencing (as opposed to bulk sequencing, where smaller deviations can be missed) of convalescent patients’ B cells, are crucial for identifying a wide range of antibody targets. This approach ensures that no promising leads are missed, accelerating the development of effective therapies.
Memory B Cells and Longitudinal Immunity
What are B cells (B lymphocytes)?
B cells are a type of white blood cell that makes infection-fighting proteins called antibodies. B cells are an important part of your immune system, your body’s defense against harmful pathogens (viruses, bacteria and parasites) that enter your body and make you sick.
B cells and T cells are a specific type of white blood cell called lymphocytes. Lymphocytes fight harmful invaders and abnormal cells, like cancer cells. T cells protect you by destroying pathogens and sending signals that help coordinate your immune system’s response to threats. B cells make antibodies in response to antigens (antibody generators). Antigens are markers that allow your immune system to identify substances in your body, including harmful ones like viruses and bacteria.
B cells are also called B lymphocytes.
What are the different types of B cells?
There are two main types of B cells: plasma cells and memory cells. Both types help protect you from infection and disease.
- Plasma cells: Plasma cells release antibodies in response to antigens. Once a B cell becomes a mature plasma cell, it can release up to 2,000 antibodies per second. Plasma cells are also called plasmacytes or effector cells. They have a shorter lifespan than memory cells.
- Memory cells: Memory cells remember particular antigens so, if they appear in your body in the future, your immune system can mount a defense quickly. While plasma cells fight bodily invaders by producing antibodies, memory cells help your immune system fight in the future. For example, most vaccines work because they expose your immune system to antigens that your memory cells remember. If an invader appears, your body can mount an attack quickly.
Memory B cells provide sustained immunity by quickly responding to future infections. Understanding their development and persistence is key to creating vaccines or therapies with longer-lasting effects.
Challenges in Production and Distribution
– Production Costs: High costs associated with producing monoclonal and bispecific antibodies may limit widespread use. Monoclonal antibodies used for COVID-19 treatment include brands like Bamlanumab, Casirivimab, Bebtacs, and others. Each has its own pricing structure.
Example:
- Bamlanumab: Approximately $2,000 per dose.
- Casirivimab: Around $1,100 per dose.
– Equity Issues: Ensuring equitable distribution is vital to prevent disparities in treatment outcomes, as seen during the initial phases of COVID-19. Getting vaccines into the hands of the most vulnerable as quickly as possible should be prioritized, regardless of socioeconomic standing, etc. This needs to be a government priority.
As you can see, antibodies hold significant potential as a therapeutic tool against SARS-CoV2. Their types, development processes, and real-world applications highlight their effectiveness when used promptly and equitably. Addressing production costs, delivery methods, and equity remains crucial for maximizing global health impact. As research evolves, so too should efforts to enhance antibody therapies, ensuring they become a cornerstone in the fight against COVID-19 and future viral threats.
Sources:
https://www.science.org/doi/10.1126/scitranslmed.adq5720
https://my.clevelandclinic.org/health/body/24669-b-cells
https://pmc.ncbi.nlm.nih.gov/articles/PMC8709896/