Methods
What method was used to measure antibody diversity before and after measles infection?
VirScan epitope profiling assay.
What is shown on the X and Y axes, and what does the figure measure overall?
X-axis: study groups (control A, control B, MV negative, MV mild, MV severe). Y-axis: proportion of antibody repertoire retained at time 2 compared with time 1. The figure measures how much of each child’s antibody repertoire was preserved after measles infection versus controls.
What is shown on the X- and Y-axis, and what does the figure measure overall?
X-axis: study groups (Control A, Control B, MV mild, MV severe).
Y-axis: fold-change geometric mean of Epitope Binding Signal (EBS) at time 2 versus time 1.
The figure measures how strongly antibodies bind to viral and bacterial epitopes after measles infection compared with before infection.
What is immune amnesia, and how is it caused by measles infection?
Immune amnesia is the loss of pre-existing immune memory caused when measles virus infects and destroys memory B and T cells, erasing antibodies built from past infections or vaccinations.
What does VirScan measure?
The diversity of antibodies recognizing and binding to epitopes.
What does each dot in the figure represent?
Each dot represents one child’s measured antibody repertoire retention after measles infection or in control groups.
What does each point in Figure 3A represent?
Each point represents the fold change in geometric mean epitope binding signal (EBS) for one pathogen species in a child before and after measles infection.
How does immune amnesia affect a person’s risk for other infectious diseases after measles?
After measles, people become more vulnerable to other infections for months or even years because their protective antibodies against many pathogens are lost.
How are bacteriophages used in the VirScan technique?
Each bacteriophage was “tagged” with an epitope on its surface, which allowed us to see which peptides the person’s antibodies bound to.
How does measles infection affect antibody repertoire retention compared to controls?
Children infected with measles retained a much smaller fraction of their preexisting antibody repertoire than controls, showing significant immune memory loss (****P < 0.0001)
How does measles infection affect the epitope binding signal compared to the control groups?
Children with mild or severe measles showed a major reduction in epitope binding signal (EBS) compared with both control groups, indicating less antibody binding after infection (***P< 0.001 to ****P< 0.0001).
How does the MMR vaccine differ from natural measles infection in terms of immune memory?
The MMR vaccine safely stimulates immune memory without destroying existing antibodies, strengthening long-term immunity and preventing immune amnesia.
What is epitope binding signal (EBS), and how does it quantify a change in immune amnesia?
EBS measures antibody titre for each epitope. A lower EBS after infection indicates that antibodies recognizing an epitope have been lost, resulting in decreased immune memory.
What is the key takeaway from Figure 2A about measles and immune memory?
Measles infection erases a large proportion of preexisting antibodies, demonstrating “immune amnesia,” whereas uninfected children retain their antibody repertoires.
What key conclusion can be drawn from Figure 3A about immune function after measles infection?
Measles infection significantly diminishes the number of antibody-antigen binding across multiple pathogens, confirming that measles not only decreases the diversity of immune memory but also the quantity of antibody secretion.
What do the findings from Figures 2A and 3A suggest about the global impact of measles on public health?
Measles infection erases much of the immune system's memory, weakening protection against many other pathogens for months to years. This immune amnesia increases secondary infection rates and child mortality worldwide, while MMR vaccination prevents both measles and this immune suppression.