Question:In healthy children, what are the benefits and harms of vaccines for preventing influenza?

Clinical Answer:

Randomized controlled trials show that, in healthy children 6 months to 15 years, live or inactivated influenza vaccine reduces rates of laboratory-confirmed influenza and cases of influenza-like illness compared with placebo or no vaccine. 

Randomized controlled trials (RCTs) including around 9,000 children, most aged under 6 years, found that live influenza vaccine reduced laboratory-confirmed cases of influenza. Live influenza vaccine reduced cases of influenza-like illness in trials including around 190,000 children.

In RCTs including around 1,600 children, inactivated influenza vaccine reduced laboratory-confirmed influenza compared with placebo or no intervention.  There was also reduction in cases of influenza-like illness in trials including around 19,000 children.

Results from meta-analyses of cohort studies were consistent with the results of the randomized controlled trials; both rates of influenza and influenza-like illness were lower in children receiving vaccine.

There was weak evidence from a cohort study with 83 participants aged over 6 years that live attenuated vaccine reduced rates of laboratory-confirmed influenza compared with placebo or no intervention.  An analysis of 22,077 children aged over age 6 years, primarily from one very large cohort study, showed that live attenuated vaccine also reduced cases of influenza-like illness.

Available studies did not report on lower respiratory tract disease, cases admitted to hospital, or school absenteeism. It is interesting that none of the studies reported adverse events so the benefit-risk ratio of vaccine as a preventive intervention is difficult to calculate from these studies.

Full outcome data is detailed below:

1.Live vaccine versus placebo or no intervention (Randomized controlled trials)

  • Population, Intervention, Comparator

    Population:

    Healthy children (6 months to 15 years)

    Intervention:

    Live vaccine

    Comparator:

    Placebo or no intervention

  • OUTCOME 1.1: Cases of influenza

    Risk of bias of studies:

    The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

    Narrative result:

    Six RCTs with 9175 participants found that vaccine reduced the proportion of children with laboratory-confirmed influenza compared with placebo or no intervention. Subgroup analyses by dose (one-dose or two-doses) found similar results to the main analysis. Subgroup analysis by age showed that the effect may be less marked in children over 6 years. Click below for full details.

    Relative effect or mean difference:

    There was a statistically significant difference between groups, in favor of vaccine (RR 0.20, 95% CI 0.13 to 0.32).

    Forest plot from Cochrane Review

    Absolute effect:

    3 per 100 people (95% CI 2 to 5) with vaccine compared with 16 per 100 people with placebo or no intervention.

    Reference:
    Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
    • Subgroup analysis 1.1.1: Cases of influenza - [subgroup: under 6 years]
      Risk of bias of studies:

      The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

      Narrative result:

      Six RCTs with 9115 participants found that vaccine reduced the proportion of children with laboratory-confirmed influenza compared with placebo or no intervention.

      Relative effect or mean difference:

      There was a statistically significant difference between groups, in favor of vaccine (RR 0.18, 95% CI 0.11 to 0.29).

      Forest plot from Cochrane Review

      Absolute effect:

      3 per 100 people (95% CI 2 to 5) with vaccine compared with 16 per 100 people with placebo or no intervention.

      Reference:
      Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
    • Subgroup analysis 1.1.2: Cases of influenza - [subgroup: over 6 years]
      Risk of bias of studies:

      The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

      Narrative result:

      One RCT with 60 participants found that vaccine reduced the proportion of children with laboratory-confirmed influenza compared with placebo or no intervention.

      Relative effect or mean difference:

      There was a statistically significant difference between groups, in favor of vaccine (RR 0.47, 95% CI 0.23 to 0.97).

      Forest plot from Cochrane Review

      Absolute effect:

      24 per 100 people (95% CI 12 to 50) with vaccine compared with 52 per 100 people with placebo or no intervention.

      Reference:
      Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
  • OUTCOME 1.2: Cases of influenza-like illness

    Risk of bias of studies:

    The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

    Narrative result:

    Eight RCTs with 188418 participants found that vaccine reduced the proportion of children with influenza-like illness compared with placebo or no intervention. Subgroup analyses by dose (one-dose or two-doses) found similar results to the main analysis as did subgroup analysis by age (under or over 6 years).

    Relative effect or mean difference:

    There was a statistically significant difference between groups, in favor of vaccine (RR 0.67, 95% CI 0.62 to 0.72).

    Forest plot from Cochrane Review

    Absolute effect:

    17 per 100 people (95% CI 16 to 19) with vaccine compared with 26 per 100 people with placebo or no intervention.

    Reference:
    Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
    • OUTCOME 1.3: Lower respiratory tract disease; Cases admitted to hospital; School absenteeism; Adverse events

      Narrative result:

      The reviewers found no studies assessing these outcomes.

      Reference:
      Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]

      2.Inactivated vaccine versus placebo or no intervention (Randomized controlled trials)

      • Population, Intervention, Comparator

        Population:

        Healthy children (6 months to 15 years)

        Intervention:

        Inactivated vaccine

        Comparator:

        Placebo or no intervention

      • OUTCOME 2.1: Cases of influenza

        Risk of bias of studies:

        The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

        Narrative result:

        Five RCTs with 1628 participants found that vaccine reduced the proportion of children with laboratory-confirmed influenza compared with placebo or no intervention. Subgroup analyses by dose (one-dose or two-doses) found similar results to the main analysis . Subgroup analysis in children aged under 2 years showed the vaccine was no more effective than placebo at reducing the proportion of children with laboratory-confirmed influenza. Subgroup analyses in children under and over 6 years showed results similar to the main analysis, although results in children under 6 years did not reach statistical significance. Click below for full details.

        Relative effect or mean difference:

        There was a statistically significant difference between groups, in favor of vaccine (RR 0.41, 95% CI 0.29 to 0.59).

        Forest plot from Cochrane Review

        Absolute effect:

        12 per 100 people (95% CI 9 to 18) with vaccine compared with 30 per 100 people with placebo or no intervention.

        Reference:
        Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
        • Subgroup analysis 2.1.1: Cases of influenza - [subgroup: under 2 years]
          Risk of bias of studies:

          The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

          Narrative result:

          Two RCTs with 786 participants found no statistically significant difference between groups.

          Relative effect or mean difference:

          There was no statistically significant difference between groups (RR 0.55, 95% CI 0.18 to 1.69).

          Forest plot from Cochrane Review

          Absolute effect:

          There was no statistically significant difference between groups.

          Reference:
          Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
        • Subgroup analysis 2.1.2: Cases of influenza - [subgroup: under 6 years]
          Risk of bias of studies:

          The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

          Narrative result:

          Two RCTs with 132 participants found no statistically significant difference between groups.

          Relative effect or mean difference:

          There was no statistically significant difference between groups (RR 0.61, 95% CI 0.34 to 1.08).

          Forest plot from Cochrane Review

          Absolute effect:

          There was no statistically significant difference between groups.

          Reference:
          Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
        • Subgroup analysis 2.1.3: Cases of influenza - [subgroup: over 6 years]
          Risk of bias of studies:

          The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

          Narrative result:

          Three RCTs with 710 participants found that vaccine reduced the proportion of children with laboratory-confirmed influenza compared with placebo or no intervention.

          Relative effect or mean difference:

          There was a statistically significant difference between groups, in favor of vaccine (RR 0.31, 95% CI 0.22 to 0.45).

          Forest plot from Cochrane Review

          Absolute effect:

          9 per 100 people (95% CI 7 to 13) with vaccine compared with 30 per 100 people with placebo or no intervention.

          Reference:
          Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
      • OUTCOME 2.2: Cases of influenza-like illness

        Risk of bias of studies:

        The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

        Narrative result:

        Five RCTs with 19388 participants found that vaccine reduced the proportion of children with influenza-like illness compared with placebo or no intervention. Subgroup analyses by dose (one-dose or two-doses) found similar results to the main analysis. Subgroup analysis by age found a greater effect in children less than 6 years. Click below for full details.

        Relative effect or mean difference:

        There was a statistically significant difference between groups, in favor of vaccine (RR 0.64, 95% CI 0.54 to 0.76).

        Forest plot from Cochrane Review

        Absolute effect:

        21 per 100 people (95% CI 18 to 25) with vaccine compared with 33 per 100 people with placebo or no intervention.

        Reference:
        Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
        • Subgroup analysis 2.2.1: Cases of influenza-like illness - [subgroup: under 6 years]
          Risk of bias of studies:

          The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

          Narrative result:

          Three RCTs with 476 participants found that vaccine reduced the proportion of children with influenza-like illness compared with placebo or no intervention.

          Relative effect or mean difference:

          There was a statistically significant difference between groups, in favor of vaccine (RR 0.39, 95% CI 0.21 to 0.69).

          Forest plot from Cochrane Review

          Absolute effect:

          15 per 100 people (95% CI 8 to 26) with vaccine compared with 38 per 100 people with placebo or no intervention.

          Reference:
          Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
        • Subgroup analysis 2.2.2: Cases of influenza-like illness - [subgroup: over 6 years]
          Risk of bias of studies:

          The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall around 40% of the studies in the systematic review were at low risk of selection and attrition bias and blinding had been performed in 60% of the studies.

          Narrative result:

          Four RCTs with 18912 participants found that vaccine reduced the proportion of people with influenza-like illness compared with placebo or no intervention.

          Relative effect or mean difference:

          There was a statistically significant difference between groups, in favor of vaccine (RR 0.72, 95% CI 0.66 to 0.78).

          Forest plot from Cochrane Review

          Absolute effect:

          24 per 100 people (95% CI 22 to 26) with vaccine compared with 33 per 100 people with placebo or no intervention.

          Reference:
          Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
      • OUTCOME 2.3: Lower respiratory tract disease; Cases admitted to hospital; School absenteeism; Adverse events

        Narrative result:

        The reviewers found no studies assessing these outcomes.

        Reference:
        Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]

        3.Inactivated vaccines versus placebo or no intervention (Cohort studies)

        • Population, Intervention, Comparator

          Population:

          Healthy children (6 months to 15 years)

          Intervention:

          Inactivated vaccines

          Comparator:

          Placebo or no intervention

        • OUTCOME 3.1: Cases of influenza

          Risk of bias of studies:

          The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall most of the studies in this comparison had an unclear risk of bias for all domains.

          Narrative result:

          Six cohort studies with 1873 participants found that vaccine reduced the proportion of children with laboratory-confirmed influenza compared with placebo or no intervention. Subgroup analyses by age found inconclusive results. Click below for full details.

          Relative effect or mean difference:

          There was a statistically significant difference between groups, in favor of vaccine (RR 0.42, 95% CI 0.25 to 0.73).

          Forest plot from Cochrane Review

          Absolute effect:

          3 per 100 people (95% CI 2 to 5) with vaccine compared with 7 per 100 people with placebo or no intervention.

          Reference:
          Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
          • Subgroup analysis 3.1.1: Cases of influenza - [subgroup: under 2 years]
            Risk of bias of studies:

            The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall most of the studies in this comparison had an unclear risk of bias for all domains.

            Narrative result:

            Three cohort studies with 314 participants found no statistically significant difference between groups.

            Relative effect or mean difference:

            There was no statistically significant difference between groups (RR 0.63, 95% CI 0.27 to 1.47).

            Forest plot from Cochrane Review

            Absolute effect:

            There was no statistically significant difference between groups.

            Reference:
            Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
          • Subgroup analysis 3.1.2: Cases of influenza - [subgroup: under 6 years]
            Risk of bias of studies:

            The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall most of the studies in this comparison had an unclear risk of bias for all domains.

            Narrative result:

            One cohort study with 180 participants found that vaccine reduced the proportion of people with influenza compared with placebo or no intervention.

            Relative effect or mean difference:

            There was a statistically significant difference between groups, in favor of vaccine (RR 0.34, 95% CI 0.13 to 0.89).

            Forest plot from Cochrane Review

            Absolute effect:

            6 per 100 people (95% CI 2 to 15) with vaccine compared with 17 per 100 people with placebo or no intervention.

            Reference:
            Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
          • Subgroup analysis 3.1.3: Cases of influenza - [subgroup: over 6 years]
            Risk of bias of studies:

            The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall most of the studies in this comparison had an unclear risk of bias for all domains.

            Narrative result:

            Two cohort studies with 1379 participants found no statistically significant difference between groups.

            Relative effect or mean difference:

            There was no statistically significant difference between groups (RR 0.36, 95% CI 0.12 to 1.11).

            Forest plot from Cochrane Review

            Absolute effect:

            There was no statistically significant difference between groups.

            Reference:
            Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
        • OUTCOME 3.2: Cases of influenza-like illness

          Risk of bias of studies:

          The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall most of the studies in this comparison had an unclear risk of bias for all domains.

          Narrative result:

          11 cohort studies with 11935 participants found that vaccine reduced the proportion of people with influenza-like illness compared with placebo or no intervention. Subgroup analyses by age found similar results to the main analysis.

          Relative effect or mean difference:

          There was a statistically significant difference between groups, in favor of vaccine (RR 0.53, 95% CI 0.42 to 0.67).

          Forest plot from Cochrane Review

          Absolute effect:

          26 per 100 people (95% CI 20 to 33) with vaccine compared with 49 per 100 people with placebo or no intervention.

          Reference:
          Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
          • OUTCOME 3.3: Lower respiratory tract disease; Cases admitted to hospital; School absenteeism; Adverse events

            Narrative result:

            The reviewers found no studies assessing these outcomes.

            Reference:
            Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]

            4.Live attenuated vaccines versus placebo or no intervention (Randomized controlled trials)

            • Population, Intervention, Comparator

              Population:

              Healthy children (6 months to 15 years)

              Intervention:

              Live attenuated vaccines

              Comparator:

              Placebo or no intervention

            • OUTCOME 4.1: Cases of influenza, Cases of influenza-like illness, Lower respiratory tract disease, Cases admitted to hospital, School absenteeism, Adverse events

              Narrative result:

              The reviewers found no RCTs assessing this comparison.

              Reference:
              Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]

              5.Live attenuated vaccines versus placebo or no intervention (Cohort studies)

              • Population, Intervention, Comparator

                Population:

                Healthy children (6 months to 15 years)

                Intervention:

                Live attenuated vaccines

                Comparator:

                Placebo or no intervention

              • OUTCOME 5.1: Case of influenza

                Risk of bias of studies:

                The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall most of the studies in this comparison had an unclear risk of bias for all domains.

                Narrative result:

                One cohort study with 83 participants over 6 years of age found that vaccine reduced the proportion of children with laboratory-confirmed influenza compared with placebo or no intervention.

                Relative effect or mean difference:

                There was a statistically significant difference between groups, in favor of vaccine (RR 0.56, 95% CI 0.35 to 0.91).

                Forest plot from Cochrane Review

                Absolute effect:

                36 per 100 people (95% CI 22 to 58) with vaccine compared with 64 per 100 people with placebo or no intervention.

                Reference:
                Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
                • OUTCOME 5.2: Cases of influenza-like illness

                  Risk of bias of studies:

                  The reviewers did not perform a GRADE assessment of the quality of the evidence. Overall most of the studies in this comparison had an unclear risk of bias for all domains.

                  Narrative result:

                  Two cohort studies with 22077 participants over 6 years of age found that vaccine reduced the proportion of people with influenza-like illness compared with placebo or no intervention.

                  Relative effect or mean difference:

                  There was a statistically significant difference between groups, in favor of vaccine (RR 0.63, 95% CI 0.57 to 0.69).

                  Forest plot from Cochrane Review

                  Absolute effect:

                  6 per 100 people (95% CI 6 to 7) with vaccine compared with 10 per 100 people with placebo or no intervention.

                  Reference:
                  Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]
                  • OUTCOME 5.3: Lower respiratory tract disease; Cases admitted to hospital; School absenteeism; Adverse events

                    Narrative result:

                    The reviewers found no studies assessing these outcomes.

                    Reference:
                    Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]

                    Additional Information:

                    DOI

                    10.1002/cca.319

                    Publication Dates

                    1. Published Online: 19 MAR 2014

                    CCA derived from

                    Jefferson T, Rivetti A, Di Pietrantonj C, Demicheli V, Ferroni E. Vaccines for preventing influenza in healthy children. Cochrane Database of Systematic Reviews 2012, Issue 8. Art. No.: CD004879. DOI: 10.1002/14651858.CD004879.pub4. [Review search date: November 2011]

                    How to Cite

                    In healthy children, what are the benefits and harms of vaccines for preventing influenza? Elie Mulhem (MD) (on behalf of Cochrane Clinical Answers Editors). Cochrane Clinical Answers 2012. DOI: 10.1002/cca.319.

                    Further Information

                    • CCA Associate editor: Elie Mulhem (MD), Associate Professor, Oakland University, William Beaumont School of Medicine, Detroit, MI, USA.
                    • CCA Editor: Karen Pettersen. Correspondence to kpettersen@wiley.com.