Pneumococcal Conjugate Vaccine

What Factors Predict PCV Responsiveness?

Various factors such as older age at first vaccine dose and a shorter time between vaccination and antibody measurement can affect immune responses in children who receive the 7-valent (PCV7) and 13-valent (PCV13) pneumococcal vaccines, a recent study found.

For their study, the researchers evaluated immunogenicity data from a trial that had compared the PCV7 and PCV13 vaccines. Associations between serotype-specific immunoglobulin G (IgG) levels were determined. Demographic predictors of response were assessed via multiple regressions.

PCV13 Is Effective in Middle-Aged Adults
PCV13 Vaccination Still Low Among Older Adults, Despite Recommendations

Results demonstrated a moderately positive correlation between vaccine-induced IgG levels (pairwise correlation coefficients 0.40 to 0.70). According to principle component analysis of vaccine-serotype responses, 1 principal component showed general immune responsiveness, and another showed responses to serotype 14, which was the least correlated with the other responses.

The researchers noted that demographic variables only accounted for 17.0% of mean PCV7 responses and 20.4% of mean PCV13 responses. They also found that older age at first dose and shorter time between vaccination and antibody measurement were independently associated with stronger geometric mean responses.

“Improved understanding of the nature and causes of variation in immune response may aid in optimizing vaccination schedules and identifying robust correlates of protection,” the researchers concluded.

—Christina Vogt


Lipsitch M, Li LM, Patterson S, et al. Serotype-specific immune responses to pneumococcal conjugate vaccine among children are significantly correlated by individual: analysis of randomized controlled trial data. Vaccine. 2018;36(4):473-478.