A toddler PCV booster dose following 3 infancy priming doses increases circulating serotype-specific IGG levels but does not increase protection against carriage

作者：Dagan Ron; Ben Shimol Shalom; Simell Birgit; Greenberg David; Porat Nurith; Kayhty Helena; Givon Lavi Noga

来源：Vaccine, 2018, 36(20): 2774-2782.

DOI：10.1016/j.vaccine.2018.04.007

• Pneumococcal conjugate vaccines
• PCV
• Carriage
• Serologic response
• Booster
• Vaccine schedule
• Infants
• Toddlers

Background: We compared PCV7 serological response and protection against carriage in infants receiving 3 doses (2, 4, 6 months; 3+0 schedule) to those receiving a booster (12 months; 3+1).
Methods: A prospective, randomized controlled study, conducted between 2005 and 2008, before PCVs were implemented in Israel. Healthy infants were randomized 1:1:1 to receive 3+1, 3+0 and 0+2 (control group; 12, 18 months doses). Nasopharyngeal/oropharyngeal swabs were obtained at all visits. Serum serotype-specific IgG concentrations and opsonic activities (OPA) were measured at 2, 7, 13 and 19 months. This study was registered with Current Controlled Trials, Ltd. ISRCTN28445844.
Results: Overall, 544 infants were enrolled: 3+1 (n = 178), 3+0 (n = 178) and 0+2 (n = 188).
Post-priming (7 months), antibody concentrations were similar in both groups, except for serotype 18C (higher in 3+0).
Post-booster (13, 19 months), ELISA and OPA levels were significantly higher in 3+1 than in 3+0 group.
Nasopharyngeal/oropharyngeal cultures were positive for Streptococcus pneumoniae in 2673 (543%) visits. Acquisition rates (vaccine and non-vaccine serotypes) were similar for 3+1 and 3+0 groups at 7-30 months and for 0+2 group at 19-30 months.
Conclusions: PCV7 booster after 3 priming doses increased substantially IgG concentrations but did not further reduced vaccine-serotype nasopharyngeal acquisition, suggesting that protection from pneumococcal carriage does not depend primarily on serum IgG.

• 出版日期2018-5-11