1 Summary

This report investigate the abundance of plasmablast (and other B cell subsets) over time after vaccination with Pneumovax, Fluzone, or no vaccination (saline control group).

It can be seen on the three figures below that the plasmablast subset peaks at day 7 in both vaccine groups, with a stronger and more durable response with Pneumovax.

As expected, there is no clear peak in the saline group. These results are similar to those reported in Figure 6B of Obermoser et al. (2013) published as part of the original study.

2 Load ImmuneSpaceR and other libraries

library(ImmuneSpaceR)
library(ggplot2)
library(data.table)

3 Connect to the study and get the flow cytometry results

study <- CreateConnection(c("SDY180"))
dt_fcs <- study$getDataset("fcs_analyzed_result")

4 Subset the population of interest

dt_fcs19 <- dt_fcs[population_name_reported %like% "Plasma"]
dt_fcs19 <- dt_fcs19[, cohort := gsub("Study g", "G", cohort), ]

5 Compute the median

dt_fcs19_median <- dt_fcs19[, .(median_cell_reported = median(as.double(population_cell_number) + 1,
                   na.rm = TRUE)), by = .(cohort,study_time_collected, population_name_reported)]

6 Flow cytometry vs. ELISPOT

ggplot(dt_fcs19, aes(x = as.factor(study_time_collected), y = as.double(population_cell_number) + 1)) +
  geom_boxplot() + 
  geom_jitter() + 
  scale_y_log10() + 
  facet_grid(cohort~population_name_reported, scale = "free") + 
  xlab("Time") + 
  ylab(expression(paste("Number of cells/", mu, "l"))) + 
  geom_line(data = dt_fcs19_median, aes(x = as.factor(study_time_collected), y = as.double(median_cell_reported),
  group = 1), color = "black", size = 1.2) + 
  labs(title = "Plasma cell abundance after vaccination") + 
  theme_IS()