The immunogenicity of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) was assessed and compared with the 7-valent pneumococcal conjugate vaccine (7vCRM).
Healthy subjects (1650) were randomized to be vaccinated with 3 doses of PHiD-CV or 7vCRM (Prevenar/Prevnar) at 2-3-4 months of age and a fourth booster dose at 12-18 months. Serotype-specific pneumococcal responses (GlaxoSmithKline's ELISA with 22F-inhibition) and opsonophagocytic activity (OPA) were measured 1 month after primary and booster vaccinations.
The primary objective to demonstrate noninferiority of PHiD-CV versus 7vCRM (in terms of percentage of subjects with antibody concentration >or=0.2 microg/mL) for at least 7 of the 10 vaccine serotypes was reached as noninferiority was demonstrated for 8 serotypes. Although, noninferiority could not be demonstrated for ELISA responses against serotypes 6B and 23F, a post-hoc analysis of the percentage of subjects with OPA titers >or=8 suggested noninferiority for the 7 serotypes common to both vaccines including 6B and 23F.Priming of the immune system against all vaccine serotypes was confirmed by robust increases in ELISA antibody levels ( approximately 6.0-17 fold) and OPA titers ( approximately 8-93 fold) after a fourth consecutive dose of PHiD-CV.
PHiD-CV induces ELISA and functional OPA antibodies for all vaccine serotypes after primary vaccination and is noninferior to 7vCRM in terms of ELISA and/or OPA threshold responses. Effective priming is further indicated by robust booster responses.
"PCV13 covers an additional three—3, 6A and 19A (i.e., six more than PCV7) . Evidence shows that their safety and immunogenicity profiles of these higher valences vaccines are similar to that of PCV7 and they do not interference with other vaccines in young children  . "
"Schedules using all PCV7 doses and those starting with PCV7 and finishing with PCV13 (products made by the same manufacturer, Pfizer, and using the same carrier protein, CRM197) result in comparable antibody levels for the 7 serotypes in common between the 2 vaccines, but somewhat lower antibody levels for the 6 additional serotypes in PCV13.4 In the 1 study in which children received 3 primary doses with PCV7 and were then boosted with either PCV7 or PCV10 (a product made by a different manufacturer using a different carrier protein), antibody levels were higher for children receiving all PCV7 doses, especially for serotypes 6B and 23F, although functional activities measured by opsonophagocytic assays were similar.69 In practice, programs that were using PCV7 often simply have children receive PCV13 or PCV10 at their next scheduled dose. "
[Show abstract][Hide abstract] ABSTRACT: Since second generation pneumococcal conjugate vaccines (PCVs) targeting 10 and 13 serotypes became available in 2010, the number of national policy makers considering these vaccines has steadily increased. An important consideration for a national immunization program is the timing and number of doses-the schedule-that will best prevent disease in the population. Data on disease epidemiology and the efficacy or effectiveness of PCV schedules are typically considered when choosing a schedule. Practical concerns, such as the existing vaccine schedule, and vaccine program performance are also important. In low-income countries, pneumococcal disease and deaths typically peak well before the end of the first year of life, making a schedule that provides PCV doses early in life (eg, a 6-, 10- and 14-week schedule) potentially the best option. In other settings, a schedule including a booster dose may address disease that peaks in the second year of life or may be seen to enhance a schedule already in place. A large and growing body of evidence from immunogenicity studies, as well as clinical trials and observational studies of carriage, pneumonia and invasive disease, has been systematically reviewed; these data indicate that schedules of 3 or 4 doses all work well, and that the differences between these regimens are subtle, especially in a mature program in which coverage is high and indirect (herd) effects help enhance protection provided directly by a vaccine schedule. The recent World Health Organization policy statement on PCVs endorsed a schedule of 3 primary doses without a booster or, as a new alternative, 2 primary doses with a booster dose. While 1 schedule may be preferred in a particular setting based on local epidemiology or practical considerations, achieving high coverage with 3 doses is likely more important than the specific timing of doses.
The Pediatric Infectious Disease Journal 01/2014; 33 Suppl 2(Suppl 2 Optimum Dosing of Pneumococcal Conjugate Vaccine For Infants 0 A Landscape Analysis of Evidence Supportin g Different Schedules):S172-81. DOI:10.1097/INF.0000000000000076 · 2.72 Impact Factor
"Quantitative serotype-specific anticapsular polysaccharide IgG antibody levels ≥0.35 g/ml after the primary series are considered to correlate with protection and have been used for licensure of PCV7 and PCV13 . For licensure of PCV10 IgG antibody levels after the primary series of ≥0.20 g/ml, measured in an ELISA with 22F inhibition, was used  . Besides the amount of antibodies after vaccination also the quality of these antibodies is important. "
[Show abstract][Hide abstract] ABSTRACT: The seven-valent pneumococcal conjugate vaccine (PCV7) has been introduced in most high-income countries, although with differences in age, timing and number of primary doses before 6 months of age and presence and timing of a booster vaccination. The objective was to determine and compare the IgG antibody levels and functionality of IgG responses (avidity and opsonophagocytoses) at 1 and 2 years of age following 2 primary doses with a booster at 11 or 24 months of age. Children received PCV7 at 2 and 4 months (2-dose group), or at 2, 4 and 11 months (2+1-dose group), or no PCV7 (controls) before 1 year of age. All children received a PCV7 dose at 24 months of age. At the age of 12 months, the 2+1-dose group had higher IgG levels and functional antibody levels, compared to the 2-dose group for all serotypes, but at 25 months the difference between the 2-dose and 2+1 dose groups had disappeared for most serotypes. The kinetics of opsonophagocytic antibodies were in line with the specific IgG antibody levels for most serotypes, although differences between the 2-dose and the 2+1-dose group were more pronounced in OPA activity as compared to the IgG levels especially at the age of 24 months. Delaying the booster dose from 11 months to 24 months after 2 primary series doses resulted in significantly higher OPA GMTs one month after the booster dose. This must, however, be balanced against the risk of leaving children unboosted between the age of 11 and 24 months at a time when disease risk is still high. Local decisions about the timing of a booster dose should also take into account vaccine coverage and the indirect herd effect in a well vaccinated population. Trial registration clinicaltrials.gov Identifier: NCT00189020.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.