Final answer:
A polysaccharide-based vaccine typically induces a weaker and less durable immune response compared to a protein-based vaccine. Polysaccharides only stimulate humoral immunity, hence they often require booster shots for effective immunity. Conjugate vaccines combine polysaccharides with proteins to enhance immune responses.
Step-by-step explanation:
Vaccine Responses to Protein Vs. Polysaccharide Antigens
When a vaccine is comprised of polysaccharides instead of proteins, the immune response is typically weaker than that seen with protein antigens. Proteins are more complex in structure and can stimulate both humoral and cellular immunity, whereas polysaccharides are less complex and generally only stimulate humoral immunity. This means that a polysaccharide-based vaccine may not provide as strong or as long-lasting an immune response as a protein-based vaccine. Instead of generating a potent response with long-term memory, polysaccharide vaccines often require booster shots to achieve the desired level of immunity. A common strategy to enhance the immunogenicity of polysaccharides is to conjugate them to proteins, forming a conjugate vaccine, which enhances the immune response to the polysaccharide.
In this context, if a vaccine is comprised of polysaccharides, the likely resulting immune response is a mixture of (A) and (C) - there might be a short-lived response, and memory may not be as robust unless the vaccine is given multiple times, or it is a conjugate vaccine that includes a protein to enhance the immune response.