Update on the Use of Conjugate Pneumococcal Vaccines in Childhood

The National Advisory Committee on Immunization (NACI)† provides the Public Health Agency of Canada (PHAC) with ongoing and timely medical, scientific, and public health advice relating to immunization. PHAC acknowledges that the advice and recommendations set out in this statement are based upon the best current available scientific knowledge and is disseminating this document for information purposes. People administering the vaccine should also be aware of the contents of the relevant product monograph(s). Recommendations for use and other information set out herein may differ from that set out in the product monograph(s) of the Canadian manufacturer(s) of the vaccine(s). Manufacturer(s) have sought approval of the vaccine(s) and provided evidence as to its safety and efficacy only when it is used in accordance with the product monographs. NACI members and liaison members conduct themselves within the context of the PHAC’s Policy on Conflict of Interest, including yearly declaration of potential conflict of interest.


Introduction
This statement will supplement previous conjugate pneumococcal statements (1)(2)(3) and provide information regarding a newly authorized conjugate vaccine against pneumococcal disease, Prevnar ® 13 (PNEU-C-13).It is anticipated that adult pneumococcal immunization programs will be changing over the next few years, as other vaccines are in development and as new data on Synflorix ™ (PNEU-C-10) and PNEU-C-13 is published.These vaccines and new indications for already authorized products will be reviewed in one or more additional statements once they are authorized or further indications are authorized for use in Canada.The 23-valent polysaccharide vaccine will not be discussed in this statement.Recommendations for its use remain unchanged.This statement will: • review existing NACI recommendations on the use of conjugate pneumococcal vaccines; • update the epidemiology of pneumococcal disease in Canada relevant to the introduction of PNEU-C-13; • provide an update on the conjugate pneumococcal vaccination schedules used in Canada; • provide a literature review on the use of 3 doses (2 infant doses +1 booster) versus 4 doses (3 infant doses +1 booster) of conjugate pneumococcal vaccines; • provide information on a newly licensed 13-valent vaccine against pneumococcal disease; and • provide recommendations for the use of the 13-valent conjugate vaccine (PNEU-C-13).

Overview of past NACI recommendations for conjugate pneumococcal vaccine
A conjugate seven-valent formulation, Prevnar ™ , (Pneu-C-7) was authorized for use in Canada in infants in 2002.NACI issued a statement (1) recommending the addition of this vaccine to the routine infant immunization schedule.Addenda to this (7)(8)(9) Between 2004 and 2009, a widespread community-based outbreak of serotype 5 disease occurred, principally in adults in western Canada. (10)(13)(14)(15) The proportion of IPD caused by serotype 19A has been increasing steadily from 2000 to 2007 in children admitted to IMPACT centers.In 2000-2001, 19A caused 2% of all IPD but increased to 14% by 2006-2007.Amongst non-PNEU-C-7 cases, 19A rose from 8% of all such cases in 2000-2001 to 19% in 2006-2007.Of all IPD caused by vaccine-preventable serotypes, the proportion of IPD caused by serotype 19A rose from 25 to 39% of the additional serotypes in PNEU-C-13 over PNEU-C-7 but represented 62% of cases caused by additional serotypes in PNEU-C-13 over PNEU-C-10. (5)ble 1 provides data on the incidence of IPD in various regions of Canada in 2007 and 2008 (after implementation of routine PNEU-C-7 vaccination programs).Table 2 provides information from the same regions on the number of cases in infants less than 5 months of age.These cases are less likely to be directly vaccine preventable, although they may be prevented indirectly by herd immunity.Figure 1 shows, for 2007 and 2008 (that is, 2 or more years after the implementation of routine PNEU-C-7 vaccination programs in all provinces), the proportion of cases in children aged 6 months to 5 years due to serotypes included in different conjugate vaccines authorized for use in Canada.These relative proportions are similar for children aged 6 to 12 months, and children aged 1 to 4 years.

Three-dose versus four-dose schedule using PNEU-C-7
At the time of publication of the May 2006 NACI statement, two published studies (16,17) reported on immunogenicity associated with three-dose immunization schedules (2+1) for PNEU-C-7(  (18) Since that time, four publications have assessed the clinical efficacy of three-dose schedules of PNEU-C-7 for routine infant immunization (Table 5).Whitney et al. (19) used a case control study to determine PNEU-C-7 vaccine effectiveness during the US vaccine shortage (2001-2004).From this data, two doses given prior to 7 months of age with an additional booster at 12 to 16 months provided 96% (95% CI 75-100%) vaccine effectiveness against IPD.Vestrheim et al. (20) described the effectiveness of a three-dose schedule using PNEU-C-7 in Norwegian children.The program was introduced into the routine infant schedule in July 2006 with doses at 3, 5 and 12 months of age.National surveillance data was used to determine the incidence of IPD and the causative serotypes in children less than 2 years of age.In the two years prior to the introduction of PNEU-C-7, the incidence of vaccine serotype IPD was 47.1 per 100 000 population.One year after the introduction of PNEU-C-7, the incidence of vaccine serotype IPD decreased to 13.7 per 100 000, a reduction in IPD incidence of 74% (95% CI 57-85%), similar to reductions achieved in jurisdictions with four-dose schedules.Canadian data are provided by a Quebec case control study using PNEU-C-7. (21)Cases were children between the ages of 2 months and 59 months who had an episode of IPD between 2005 and 2007.Controls were identified from the provincial health registry to include five randomly selected controls per case.In children who received two doses prior to 7 months of age with an additional booster at 12-16 months of age, the estimated vaccine effectiveness was 100% (95% CI 15-100%).Similarly, a study from the Netherlands, presented in abstract form, reported a 98% reduction in the incidence of IPD caused by PNEU-C-7 serotypes in vaccine eligible children two years after implementation of routine infant vaccination with a three-dose schedule. (22)espite inferior immunogenicity of serotype 6B after two (at 2, 4 months) as compared to three (at 2, 4, 6 months) infant doses, the estimated efficacy of three doses of vaccine against serotype 6B was 94% (95% CI 77-98%) in the US case-control study (19) , and, in the Quebec study, the efficacy of one or more doses of PNEU-C-7 against serotype 6B IPD was 90% (95% CI 49-98%). (21)o studies have reported data on nasopharyngeal (NP) colonization with the use of a three-dose infant immunization schedule.A study from Israel documented no difference in the rate of nasopharyngeal colonization with PNEU-C-7 serotypes in children vaccinated with three-dose versus four-dose schedules. (23)In a study from the Netherlands, children were randomized to receive no vaccine (controls), two infant doses (2 and 4 months) or two infant doses with one booster dose (2, 4 months and 11 months of age).Children and their parents were tested for NP carriage of S. pneumoniae at 12 months, 18 months and 24 months of age.In the two vaccinated groups, fewer children and their parents were colonized with S. pneumoniae (24) compared to controls suggesting that herd immunity can be maintained with two or three doses of PNEU-C-7.
Two jurisdictions in Canada currently recommend a three-dose schedule for PNEU-C-7 in healthy children.(http://www.phacaspc.gc.ca/im/ptimprog-progimpt/table-1-eng.php)During a shortage of PNEU-C-7 between August 2001 and September 2004, the Advisory Committee on Immunization Practices (ACIP) approved a three-dose schedule in the US; however, in October 2004, the ACIP once again recommended a fourdose routine infant schedule. (25)Within the European Union, in 2009, 11 of 24 countries reporting PNEU-C-7 programs used a three-dose schedule for all children, and a twelfth (Switzerland) recommended a three-dose schedule for healthy children but a four-dose schedule for children with chronic conditions increasing their risk of IPD. (26)

Three-dose versus four-dose schedule using PNEU-C-13
One study done in Italy investigated a three-dose schedule where infants were vaccinated with either PNEU-C-13 or PNEU-C-7 at 3 months, 5 months and 11 months of age. (27)ost PNEU-C-13 recipients had ELISA titres >0.35mcg/mL after two infant doses of vaccine for all serotypes except 6A, 6B and 23F.After a toddler booster dose, >90% of vaccine recipients in the PNEU-C-13 group achieved ELISA titers >0.35mcg/mL for all serotypes.The safety profile of recipients of PNEU-C-13 or PNEU-C-7 series was similar.More patients in the PNEU-C-13 arm reported irritability after one dose (P<0.05)than in the PNEU-C-7 group.Otherwise, there were no statistically significant differences in the percentage of patients in either group experiencing local reactions or unsolicited adverse events.One serious adverse event was noted in the PNEU-C-7 group (infantile spasms).At the time of writing of this statement, study results were available only as a poster presentation; therefore further information is not available. (27)evnar® 13 PNEU-C-13 is the same as PNEU-C-7 with the exception of the additional six serotypes, a modification of the conjugation for serotype 19F to improve stability, the addition of 0.02% polysorbate (Tween) 80 as emulsifier, and succinate buffer.The syringe stopper is latex free.
PNEU-C-13 is marketed in a single dose, prefilled syringe containing 0.5mL of vaccine.

Efficacy
There are currently no efficacy data available for PNEU-C-13 for any indication.It is anticipated that the licensing of future pneumococcal conjugate vaccines for protection against IPD in children will require only immunogenicity data rather than efficacy data because placebo-controlled trials are not possible and very large studies would need to be done to show differences in the incidence of IPD between vaccines differing by only a few serotypes. (28,29)

Immunogenicity
A review of the serologic correlates of protection from IPD that are used to assist in the interpretation of immunogenicity studies is provided in a recent NACI statement. (4)re than 3000 children have received PNEU-C-13 in trials comparing PNEU-C-7 to PNEU-C-13, and assessing the immune response to concurrently administered vaccines in routine childhood vaccination schedules.No studies have compared PNEU-C-13 and PNEU-C-10.
In the two pivotal studies comparing PNEU-C-13 and PNEU-C-7, non-inferiority criteria for the defined primary outcome -the percent of infants with enzyme-linked immunosorbent assay (ELISA)>0.35mcg/ml(32)(33) In both pivotal studies, the ELISA response to 6B was inferior in PNEU-C-13 as compared to PNEU-C-7 (87.3% vs. 92.4% in the US study after three doses of vaccine administered at 2, 4, 6 months) and (77.5% vs. 87.1% in the German study after three doses of vaccine at 2, 3, 4 months).Non-inferiority criteria for all secondary outcomes for response to serotype 6B were met, including non-inferiority as assessed by opsonophagocytic assay (OPA).It is, however, important to recognize that the power to detect non-inferiority for some outcomes was limited.Responses to serotype 6B were significantly lower in primary series with vaccination at 2, 3 and 4 months (77.5%), than in those with vaccination at 2, 4, 6 months (87.3%).In the German, but not the US, pivotal study, serotype 23F also failed to meet the primary non-inferiority criteria (88.7% vs 89.5% of infants with IgG by ELISA of >0.35mcg/ ml).All secondary criteria were met.When comparing geometric mean concentration (GMC) by ELISA, titres achieved after PNEU-C-13 were lower than those achieved after PNEU-C-7 for all serotypes other than 19F; however, there were no apparent differences in titers assessed by OPA.When compared to ELISA GMC measured after two doses of PNEU-C-7, ELISA GMC after two doses of PNEU-C-13 were significantly lower for 4 of 7 serotypes included in PNEU-C-7; but these differences were not present when OPA geometric mean titres (GMT) were compared.The clinical significance of these differences is not clear.
In these studies, non-inferiority for the 6 additional serotypes in PNEU-C-13 was assessed by comparing the titers achieved after PNEU-C-13 for each serotype to the titers achieved against the serotype with the lowest response after vaccination with PNEU-C-7.By this criterion, non-inferiority was met for all 6 additional serotypes in the German trial, and 5 of the 6 additional serotypes (all serotypes other than serotype 3) in the US trial.This difference may be related to geographic differences in the epidemiology and immune response to serotype 3 S. pneumoniae.In trials conducted to date, responses to serotype 3 appeared to be similar to other serotypes in European trials, but lower than responses to other serotypes in North American trials.In North American trials completed to date, after a threedose series at 2, 4, and 6 months, the percent of children with ELISA IgG of>0.35 mcg/mL to serotype 3 ranged from 63.5% to 79.6%.In comparison, in a European trial, after a three-dose series at 2, 4, and 6 months, the percent of children with EIA IgG of >0.35 mcg/mL to serotype 3 was 90.3% (95% CI 86.1-93.5%).Neither the reason for, nor the clinical implications of, these differences is known.
Three studies have examined the immunogenicity of toddler doses of PNEU-C-13 in children who have not received doses of PNEU-C-13 as infants.Wysocki et al. administered two doses of PNEU-C-13 to 112 children aged 12-23 months at first dose, and a single dose to 152 children aged 24 to 72 months of age. (53)More than 95% of children had ELISA GMC of >0.35mcg/ml post-vaccination for all 13 serotypes included in the vaccine, and the GMCs were comparable to or greater then those achieved after a routine 3-dose infant series.Grimprel et al. compared the effect of administering a single dose of PNEU-C-13 at 12 months in children who had previously been immunized with three infant doses of either PNEU-C-7 (N=137) or PNEU-C-13 (N=273). (34)At one month after the toddler dose, GMC by EIA and OPA to the 6 serotypes in PNEU-C-13 but not PNEU-C-7 were higher in the children who had received PNEU-C-13 as infants.However, 89.9% (serotype 6A), 90.1 %( serotype 5), 93.8% (serotype 3), 95.5% (serotype 1) and 100% (serotypes 7F and 19A) of children who had received only a single dose of PNEU-C-13 had EIA GMC titers of >0.35mcg/ml, and more than 97.5% of such children had OPA titers of >1:8 to all six serotypes.Silfverdal et al., in an open label study, administered a single dose of PNEU-C-13 to 116 12-month old children.Post-vaccination, all children had ELISA GMC of >0.35mcg/mL for all 13 serotypes included in the vaccine. (36)Thus, one dose of PNEU-C-13 administered at 12 months of age or later offers adequate immunogenicity, regardless of the pneumococcal infant series used.
Very few studies have looked at the immunogenicity of PNEUMOCOCCAL -CONJUGATE -VALENT doses in immunocompromised patients.Vieira et al (37) determined antibody response following the administration of 2 doses of PNEU-C-7 to 48 children between 1 and 9 years of age with chronic renal failure (both on conservative treatment and dialyzed).None of these children had been previously vaccinated with any pneumococcal vaccine.Sixty days after the second PNEU-C-7 dose, 100% of children on conservative treatment and 95.8% of dialyzed children had GMC titers ≥ 0.35 mcg/ mL.Meerveld-Eggink et al (38) determined the antibody response after 2 doses of PNEU-C-7 administered with a 6-week interval one year following reduced-intensity conditioning regimens for allogeneic stem cell transplants in 26 patients aged 44 to 67 years.Except for serotype 6B, more than 73% of the patients developed antibody levels ≥ 0.35 mcg/mL.

Schedule and Dosage
The dose for infants and children less than five years of age is 0.5 mL.The product monograph recommends that the primary immunization series consist of three doses at approximately 2-month intervals beginning at 2 months of age, followed by a fourth dose at 12-15 months of age (3+1 schedule), but adds that a 2+1 schedule may be considered, with doses given at 2 months, 4 months, and 11-12 months of age.
Children between 12 and 23 months vaccinated for the first time with a conjugate pneumococcal vaccine should receive two doses of PNEU-C-13, with at least 8 weeks between each dose.Children between 24 and 59 months vaccinated for the first time with a conjugate pneumococcal vaccine only require one dose of PNEU-C-13.

Route of Administration
Administer PNEU-C-13 by intramuscular injection.Shake the syringe well to create a homogenous white suspension, then expel air from the syringe before vaccine administration.

Booster Doses and Re-Immunization
There are no data regarding booster doses or re-immunization after completion of the routine pediatric schedule.

Serological Testing
There is no indication for routine pre-or post-immunization serology.

Storage Requirements
The vaccine should be refrigerated, with the temperature maintained between 2ºC to 8ºC.Vaccine which has been frozen should be discarded.In cases of temporary breaks in the cold chain, PNEU-C-13 has been shown to be stable at temperatures up to 40oC for up to 4 days. (39)However, practitioners should adhere to usual provincial procedures for deciding on vaccine viability following breaks in the cold chain.

Simultaneous Administration with Other Vaccines
PNEU-C-13 has been studied when given concomitantly with a number of vaccine antigens used in a childhood schedule in Canada with no adverse effect on immunogenicity or safety profile.These antigens include: diphtheria, tetanus, acellular pertussis, Haemophilus influenzae type b, inactivated poliomyelitis, rotavirus, hepatitis B, meningococcal serogroup C, measles, mumps, rubella and varicella. (40)As with general guidance given for all vaccines, PNEU-C-13 should be administered at a different site than concomitantly administered vaccines, using a different needle and syringe.

Vaccine Safety and Adverse Events
According to data provided by the manufacturer, a total of 14 studies with a safety review component have been conducted.Presented below are data in the public domain as of September 2009.
PNEU-C-13 has the same formulation as PNEU-C-7, with the exception of a modification in the conjugation for serotype 19F, and the presence of 0.02% polysorbate (Tween) 80, and succinate buffer, both of which are excipients present in other vaccines.The pivotal trials in Germany and the US used a formulation of PNEU-C-13 without Tween 80.A trial in Poland compared the reactogenicity of formulations with and without Tween 80.There was a small but statistically significantly increase in mild induration and erythema in the Tween 80 arm of the study with the first and second doses, but no differences in moderate or severe local adverse events, and statistically fewer infants that reported systemic adverse events after dose two (p<0.05). (41) total of 2116 (30,33,40,42,43) children received PNEU-C-13 as compared to PNEU-C-7 as a primary series.In one study, there were significant differences between groups in the incidence of induration (28.2% PNEU-C-13 vs. 20.5% PNEU-C-7, P= 0.04) and erythema (27.2% PNEU-C-13 vs. 36.4%PNEU-C-7, P=0.04) after any dose. (32)In the same study, more children receiving PNEU-C-7 reported increased sleep after the second vaccine dose (53.9% PNEU-C-13 vs. 66.8%PNEU-C-7, p= 0.003). (32)In other studies (41,(44)(45)(46)(47) there were no statistically significant differences in local or systemic adverse events.No differences in rates of severe adverse events, and no unanticipated adverse events were identified.
Three studies, including 844 children who received PNEU-C-13, have compared PNEU-C-13 versus PNEU-C-7 initial doses or boosters at 12 to 15 months of age.No significant differences in local or systemic adverse events were identified.Only one serious adverse event was reported -status asthmaticus in a child who had received PNEU-C-13, which was deemed unrelated to the vaccine. (32,48)

Contraindications and Precautions
PNEU-C-13 is contraindicated in any individual with a history of anaphylaxis to any component of the vaccine, including diphtheria toxoid.

Interchangeability
A single study reported that, in children who received a primary series of immunization with PNEU-C-7, a single dose of PNEU-C-13 at 12 to 15 months of age was non-inferior to a PNEU-C-7 dose for the seven serotypes in the PNEU-C-7 vaccine, and induced an antibody response >0.35mcg/mL by ELISA for the additional 6 serotypes included in PNEU-C-13 in over 90% of children. (31)There were no significant differences in rates of adverse events associated with the 12-15 month dose of PNEU-C-7 compared to PNEU-C-13 after primary immunization with PNEU-C-7.There are no other available data on the interchangeability of PNEU-C-7 and PNEU-C-13, or PNEU-C-10 and PNEU-C-13.

Summary
PNEU-C-13 use is supported by immunogenicity data suggesting protection against 6 additional serotypes, (including 19A), and by similarity in formulation to PNEU-C-7, a vaccine which has proven efficacy.However, no clinical efficacy or effectiveness data are yet available, and there is no direct evidence that correlates of immunity developed for the seven serotypes in PNEU-C-7 also apply to the six additional serotypes included in the PNEU-C-13.In addition, using the World Health Organization's agreed upon primary criterion for assessment of immunogenicity (non-inferior to PNEU-C-7 when the percentage of children with IgG >0.35 mcg/mL measured by ELISA (31) , immunogenicity to serotypes 6B and 23F are inferior to PNEU-C-7 with the currently formulated PNEUMOCOCCAL -CONJUGATE -VALENT-13 vaccine.However, reduced titers to serotypes 6B and 23F are not observed when antibody titers are measured by opsonophagocytic assays, and most experts believe that the differences are unlikely to affect direct protection against invasive pneumococcal disease.Some experts note that reduced ELISA titres might correlate with reduced protection against pneumonia, otitis media and nasopharyngeal colonization (and thus herd immunity). (47)There are no studies comparing the immunogenicity of PNEU-C-10 and PNEU-C-13.However, in studies comparing PNEU-C-10 and PNEU-C-7, there is a similar trend to that seen in studies comparing PNEU-C-13 and PNEU-C-7; that is, antibody concentrations to serotypes 6B and 23F measured by EIA after vaccination with PNEU-C-10 are somewhat lower than those achieved after vaccination with PNEU-C-7.PNEU-C-10 does not contain antigens for serotypes 3, 6A or 19A; however, it may provide some protection against otitis media due to non-typeable H. influenzae. (4)itially, North American expert recommendations were that infant conjugate pneumococcal immunization programs provide vaccination at 2, 4, and 6 months, with a booster dose at 12 to 18 months.Although immunogenicity after two doses of vaccine (at 2 and 4 months of age) is lower than that thought to be required for direct protection of individuals for some serotypes, it is clear that infant immunization schedules with three doses of PNEU-C-7 (at 2, 4 and 11 to 15 months) result in reductions in invasive pneumococcal infections that are indistinguishable from programs using four doses of PNEU-C-7.
It is not clear whether the reduced immunogenicity of PNEU-C-10 and PNEU-C-13 to serotypes 6B and 23F compared to PNEU-C-7 would reduce the effectiveness of a three-dose versus four-dose schedule of PNEU-C-10 or PNEU-C-13.It is, however, anticipated that the indirect protection against PNEU-C-7 serotypes observed with the introduction of routine heptavalent pneumococcal conjugate vaccine programs will also be observed for the additional 6 serotypes in PNEU-C-13 when PNEU-C-13 programs are introduced.In other words, it is expected that, when routine PNEU-C-13 vaccination programs are introduced, a reduction in IPD due to the 6 additional serotypes in PNEU-C-13 will be seen not only in vaccinated children, but also in unvaccinated persons (herd immunity There is evidence that a single dose of 13-valent conjugate vaccine is cost-effective for healthy children aged 24-59 months who have received complete age-appropriate vaccination with PNEU-C-7. (48)

Recommendations
For the purposes of these recommendations, we consider as high risk of IPD, children with either immunocompromise or chronic conditions that put them at increased or presumed increased risk of IPD but who are expected to mount an antibody response to conjugate pneumococcal vaccines that is close to that of healthy children.These children include those who have: • Chronic CSF leak • Chronic neurologic condition that may impair clearance of oral secretions (49) • Cochlear implants (including those children who are to receive implants) • Chronic cardiac or pulmonary disease (excluding asthma) • Poorly controlled diabetes mellitus • Asplenia (functional or anatomic) • Sickle cell disease or other hemoglobinopathies

Children at high risk for IPD aged 60 months and older
1.There is fair evidence to recommend that children at high risk for IPD receive one dose of PNEU-C-13.This dose should be given whether or not the child has already received PNEU-P-23.If the child has not previously received PNEU-P-23, one dose should be given with an interval of at least 8 weeks following the dose of PNEU-C-13 (NACI Recommendation B).

Children at high risk of IPD include children who have:
• Chronic CSF leak • Chronic neurologic condition that may impair clearance of oral secretions (49) • Cochlear implants (including those children who are to receive implants) • Chronic cardiac or pulmonary disease (excluding asthma) • Poorly controlled diabetes mellitus • Asplenia (functional or anatomic) • Sickle cell disease or other hemoglobinopathies  Followed by one dose of PNEU-P-23 8 weeks after previous PNEUMOCOCCAL -CONJUGATE -VALENT dose * Children who are at high risk of IPD should also receive a dose of PNEU-P-23 at 24 months of age.This dose should be given whether or not the child has already received PNEU-P-23.If the child has not previously received PNEU-P-23, it should be given at least 8 weeks after the last dose of PNEU-C-13.‡ The decision to vaccinate healthy children age 36-59 months of age should be make taking into account the age of the child (the incidence of IPD declines from age 24 to age 59 months), the degree of exposure to other young children, and the local epidemiology of invasive pneumococcal disease (NACI recommendation B).The benefit of vaccinating such children is expected to be greater in the next 1-3 years than in subsequent years, as it is expected that the incidence of disease due to serotypes in the 13-valent vaccine will decline due to herd immunity associated with increasing use of 13-valent pneumococcal conjugate vaccines in routine programs Children at high risk of IPD include children who have: • Chronic CSF leak • Chronic neurologic condition that may impair clearance of oral secretions (49) • Cochlear implants (including those children who are to receive implants) • Chronic cardiac or pulmonary disease (excluding asthma) • Poorly controlled diabetes mellitus • Asplenia (functional or anatomic) • Sickle cell disease or other hemoglobinopathies • Congenital immunodeficiencies involving any part of the immune system, including B-lymphocyte (humoral) immunity, T-lymphocyte (cell) mediated immunity, complement system (properdin, or factor D deficiencies), or phagocytic functions • Hematopoietic stem cell transplant (candidate or recipient) • Human immunodeficiency virus (HIV) infection • Immunosuppressive therapy including use of long term corticosteroids, chemotherapy, radiation therapy, postorgan-transplant therapy, and certain anti-rheumatic drugs • Chronic kidney disease, including nephrotic syndrome • Chronic liver disease (including hepatitis B and C, and hepatic cirrhosis due to any cause) • Malignant neoplasms including leukemia and lymphoma • Solid organ or islet cell transplant (candidate or recipient)

Surveillance and Research Priorities
The epidemiology of invasive pneumococcal disease is changing in Canada and elsewhere, both due to and independent of the use of pneumococcal vaccines.Ongoing changes are expected as PNEU-C-10 and PNEU-C-13 vaccines are used.Surveillance systems to detect these changes over time are essential.Optimal decisions about the use of pneumococcal vaccines in children requires on-going surveillance for serotype-specific rates of invasive pneumococcal disease, and other disease syndromes (e.g.frequency of empyema associated with streptococcal pneumonia), serotype-specific estimates of the efficacy of different vaccines, and continuing assessment of the effectiveness and cost-effectiveness of different vaccination schedules over time.
Surveillance and research which addresses the following outstanding questions is particularly encouraged: -Which conjugate vaccine schedule is the most effective and cost-effective for Canadian children?
-What is the impact of conjugate pneumococcal vaccines on rates of pneumococcal pneumonia and acute otitis media?

II-1
Evidence from controlled trial(s) without randomization.

II-2
Evidence from cohort or case-control analytic studies, preferably from more than one centre or research group using clinical outcome measures of vaccine efficacy.

II-3
Evidence obtained from multiple time series with or without the intervention.Dramatic results in uncontrolled experiments (such as the results of the introduction of penicillin treatment in the 1940s) could also be regarded as this type of evidence.

III
Opinions of respected authorities, based on clinical experience, descriptive studies and case reports, or reports of expert committees.

Table 7. Levels of Evidence Based on Research Design
Good A study (including meta-analyses or systematic reviews) that meets all design-specific criteria * well.

Fair
A study (including meta-analyses or systematic reviews) that does not meet (or it is not clear that it meets) at least one designspecific criterion * but has no known "fatal flaw".

Poor
A study (including meta-analyses or systematic reviews) that has at least one design-specific * "fatal flaw", or an accumulation of lesser flaws to the extent that the results of the study are not deemed able to inform recommendations.
* General design specific criteria are outlined in Harris et al., 2001. (54)ble 8.NACI Recommendation for Immunization -Grades A NACI concludes that there is good evidence to recommend immunization.

B
NACI concludes that there is fair evidence to recommend immunization.

C
NACI concludes that the existing evidence is conflicting and does not allow making a recommendation for or against immunization; however other factors may influence decision-making.

D
NACI concludes that there is fair evidence to recommend against immunization.

E
NACI concludes that there is good evidence to recommend against immunization.

I
NACI concludes that there is insufficient evidence (in either quantity and/or quality) to make a recommendation, however other factors may influence decision-making.

Figure 1
Figure 1.Percentage of isolates causing IPD in children aged 6 months to 5 years of age during 2007 and 2008 with serotypes included in different conjugate vaccines Congenital immunodeficiencies involving any part of the immune system, including B-lymphocyte (humoral) immunity, T-lymphocyte (cell) mediated immunity, complement system (properdin, or factor D deficiencies), or phagocytic functions • Hematopoietic stem cell transplant (candidate or recipient) • Human immunodeficiency virus (HIV) infection • Immunosuppressive therapy including use of long term corticosteroids, chemotherapy, radiation therapy, postorgan-transplant therapy, and certain anti-rheumatic drugs • Chronic kidney disease, including nephrotic syndrome • Chronic liver disease (including hepatitis B and C, and hepatic cirrhosis due to any cause) • Malignant neoplasms including leukemia and lymphoma • Solid organ or islet cell transplant (candidate or recipient).

•
Congenital immunodeficiencies involving any part of the immune system, including B-lymphocyte (humoral) immunity, T-lymphocyte (cell) mediated immunity, complement system (properdin, or factor D deficiencies), or phagocytic functions • Hematopoietic stem cell transplant (candidate or recipient) • Human immunodeficiency virus (HIV) infection • Immunosuppressive therapy including use of long term corticosteroids, chemotherapy, radiation therapy, postorgan-transplant therapy, and certain anti-rheumatic drugs • Chronic kidney disease, including nephrotic syndrome • Chronic liver disease (including hepatitis B and C, and hepatic cirrhosis due to any cause) • Malignant neoplasms including leukemia and lymphoma • Solid organ or islet cell transplant (candidate or recipient).

Table 4 .
Recommended schedules for conjugate pneumococcal vaccine for Canadian children aged 24Any incomplete age-appropriate vaccination schedule with any product or complete schedule with PNEU-C-7 or PNEU-C-10 (no PNEU-C-13) • 1 dose of PNEU-C-13, ≥8 weeks after most recent dose 24-35 months, high risk of IPD Any incomplete age-appropriate vaccination schedule with any product or complete schedule with PNEU-C-7 or PNEU-C-10 (no PNEU-C-13) • 1 dose of PNEU-C-13, ≥8 weeks after most recent dose; Followed by one dose of PPV 23 8 weeks after previous PNEUMOCOCCAL -CONJUGATE -VALENT dose 36-59 months healthy Complete schedule with PNEU-C-7 or PNEU-C-10 (no PNEU-C-13) Any incomplete age-appropriate vaccination schedule with any product • If of aboriginal origin or attend group child care, 1 dose of PNEU-C-13, ≥8 weeks after most recent dose • All other children, consider a single dose of PNEU-C-13 ‡ • 1 dose of PNEU-C-13 should be administered 36-59 months, high risk of IPD * Any incomplete age-appropriate vaccination schedule with any product, or complete schedule with PNEU-C-7 or PNEU-C-10 (no PNEU-C-13) • 1 dose of PNEU-C-13, ≥8 weeks after most recent dose;

Table 1 . Incidence (per 100 000) and number of cases of IPD by serotype categories among children aged less than 5 years, 2007 and 2008
‡ Data from passive, population-based surveillance for invasive pneumococcal disease are available for the provinces of British Columbia, Alberta and Quebec, and in Northern Canada (northern Labrador, northern Quebec, Nunavut, the Yukon and the Northwest Territories) as part of International Circumpolar Surveillance (ICS); active population-based surveillance is conducted in metropolitan Toronto and Peel Region (labeled as Toronto).Details of these surveillance systems can be found in reference 4. Number of cases with unknown serotypes in children less than 5 years of age were: BC 2 in 2007 and 4 in 2008; Quebec, 8 in 2007 and 7 in 2008, Toronto/Peel, 2 in 2007 and 5 in 2008; Northern Canada (ICS), none. 1 Based on number of case-isolates received for typing at the National Centre for Streptococcus *

Pneumococcal conjugate immunization schedules used in Canada, January, 2010
With the authorization for use of PNEU-C-10 in December 2008, a number of provinces and territories have changed their product of choice for pneumococcal conjugate vaccination.Please refer to the PHAC website (www.phac-aspc.gc.ca/im/ ptimprog-progimpt/table-1-eng.php), for updated information on schedule and product used by jurisdiction.

Table 5
).Both reports suggested that two doses of PNEU-C-7 given at 3 and 5 months of age provided satisfactory immune responses for serotypes other than 6B and 23F, and a third dose given after 12 months of age evoked a strong response for all serotypes.Since that time, Goldblatt et al. have confirmed these findings for two doses of PNEU-C-7 at 2 and 4 months of age, and identified that two doses given at 2 and 3 months of age resulted in significantly reduced immunogenicity for serotypes 6B and 23F, and lower 12 month EIA titers for serotypes 4 and 9V, when compared to two doses given at 2 and 4 months of age.
).For instance, if PNEU-C-13 were given only to children over the age of 12 months, protection against serotype 19A in children less than 12 months of age would be expected to arise from indirect protection from older children who have received the 13-valent vaccine.How effective this indirect protection might be, what proportion of older children need to be vaccinated to achieve protection of younger children, and how long it would take after the vaccination program starts to see reductions in disease in unvaccinated younger children are all unknown.

Table 3 (
age < 24 months) and Table4(age 24-59 months) provide detailed schedules for PNEU-C-13 for Canadian children that incorporate routine schedule recommendations and the specific recommendations provided below.
(NACI Recommendation A).Of note, programs using a 3-dose schedule should offer the 3 rd dose early in the 2 nd year of life (at 12 months of age) to allow for early complete protection.For PNEU-C-10 and PNEU-C-13, NACI concludes that there is insufficient evidence to determine whether three-dose schedules are non-inferior to four-dose schedules for healthy children (NACI Recommendation I).Provinces and territories electing to implement a PNEU-C-10 or 13 3-dose program should continue ongoing surveillance of vaccine program effectiveness.For infants at high risk for IPD, NACI concludes that there is fair evidence to recommend a four-dose schedule (NACI Recommendation B); 5.For infants who have started an immunization schedule with one conjugate vaccine, NACI concludes that there is fair evidence to recommend that they may continue their immunization schedule with a different conjugated vaccine (NACI Recommendation B)PNEUMOCOCCAL -CONJUGATE -

VALENT Dose between 12 -23 months of age For children aged 12-23 months of age who
Catch-

up Dose (24 -35 months of age) For children aged 24-35 months of age
who have not previously received a pneumococcal vaccine or completed a series, one doses of PNEU-C-13 is recommended.Children in this age group who are at high risk of IPD should also receive a dose of PNEU-P-23 with an interval between the PNEU-C-13 and PNEU-P-23 dose of at least 8 weeks (NACI Recommendation A).Moreover, it should be noted that immunocompromised children will benefit from herd immunity (indirect protection).Catch-

up Dose (36 -59 months of age) For children aged 36 -59 months of age
who have not previously received a pneumococcal vaccine or completed a series, one doses of PNEU-C-13 is recommended.Children

in this age group who are at high risk of IPD should
also receive a dose of PNEU-P-23 with an interval between the PNEU-C-13 and PNEU-P-23 dose of at least 8 weeks (NACI Recommendation A).Moreover, it should be noted that immunocompromised children will benefit from herd immunity (indirect protection).

Table 3 . Recommended schedules for conjugate pneumococcal vaccine for children under 24 months of age in Canada, by Pneumococcal -Conjugate -valent vaccination history * Age at examination Number of previous doses of PNEU-C-7, PNEU-C-10 or PNEU-C-13 received Recommended regimen if using a schedule with PNEU- C-13 only
Provincial schedules vary as to whether 3 doses (2, 4 and booster), or 4 doses (2, 4, 6, and booster) are recommended for healthy children.Prescribers should follow their relevant provincial schedule.
* Children who are at high risk of IPD should receive a dose of PNEU-P-23.Because young children do not respond to polysaccharide vaccines, the youngest age at which this dose should be given is 24 months of age.†

Table 6 . Levels of Evidence Based on Research Design
IEvidence from randomized controlled trial(s).