Efficacy and Effectiveness of Influenza Vaccines

Efficacy and Effectiveness of Influenza Vaccines

The article titled Efficacy and Effectiveness of Influenza Vaccines: A systematic Review and Meta-Analysis seeks to establish the efficacy and effectiveness of licensed influenza vaccines in the US through a meta-analysis of 31 eligible studies published between Jan 1 1967 to Feb 15 2011. Eligible studies had to be randomized trials that assessed the relative reduction in the risk of infection from the influenza virus during specific flu seasons (efficacy) and observational studies that monitored the effectiveness of the vaccine. The studies also had to be using RT-PCR or the culture method to confirm the presence of the influenza virus (Osterholm, Kelley, Sommer, & Belongia, 2012).  Comment by Audra Clark: Include a thesis statement in your introduction

By establishing the efficacy and effectiveness of the influenza vaccine the study could be used as a guide for future vaccination campaigns and help isolate target groups that may be in need of different kinds of interventions. For instance, study authors note that while those aged 65 years and older account for 90% of all fatalities resulting from flu infection, the annual vaccine seems to be the least effective and they point out to another vaccine solution that might help this demographic. The study is in a way significant given the oversized effect that the influenza virus has on the health situation in the developed world. The authors for instance note how every year, most developed nations undertake costly vaccination campaigns to prevent influenza related complications which can lead to fatalities and other complications. Thus the study’s significance lies in reducing some of these incidences. The authors also point out that the information is useful for the efforts that aim at estimating the potential health benefits of the influenza vaccination.

Method of study – consider using a heading such as this

As noted, the authors used a meta-analyses approach that involved searching for randomized controlled trials that either assessed the relative reduction in risk in catching the flu during the flu season or observational studies that met set criteria for effectiveness. In total 5707 articles were reviewed for the study in which 31 were found to be eligible (Osterholm et al., 2012). Using the information available in the articles, estimations of random effects of pooled efficacy of trivalent inactivated vaccine were made. The study design was appropriate because meta analyses combines results from multiple studies with similar methods and aims the logic being that it is easier to reduce the errors in the studies if they are all aggregated together. And given that the vaccination campaign has been going on for many years, I think that the best way to know the effectiveness of the vaccination campaigns is to look at the aggregate of the outcomes of the various studies. Indeed, the authors point out that their study is a first of its kind as no published meta analyses have assessed the efficacy and effectiveness of licensed influenza vaccines for the many years that they have been administered in the US.

As for the study methods, the authors first established criteria for study inclusion by defining both efficacy and effectiveness and then searched for studies that were published in Medline (PubMed Database) that met the said criteria. After the studies were selected, the authors went on to calculate Mantel-Haenszel fixed effects and random effects pooled odd ratios that were compared to placebo when there were more than three randomized controlled studies that had equivalent age ranges and vaccine characteristics. Homogeneity was assessed with the help of the Breslow Day Statistic (Osterholm et al., 2012).

The methods used in this case are appropriate for this kind of study and the statistical analyses employed necessary when it comes to answering the pertinent questions raised for the about the efficacy and effectiveness of the influenza vaccination campaigns. The researchers also conducted extensive research work through the use of both old and new references. The oldest reference is from 1942 while the latest is from 2011. A total of 71 references were used for this meta analyses. The results indicate that over all the efficacy of TIV in eight of the 12 randomized trials stood at 59% (95% CI) for adults aged between 18 to 65 years. No such data could be obtained for children between the ages of 2-17 years old. In children aged between 6 months to 7 years the same was found to be 83% (69-91). In observational studies vaccine effectiveness was shown to be 69%. Comment by Audra Clark: Good discussion of methodology used by the researchers


The authors thus point out that the studies show that the influenza vaccine does provide some measure of protection against confirmed influenza. (Campitelli, Rosella, Stukel, & Kwong, 2010). However, the protection is greatly diminished for some seasons and evidence that the vaccination campaigns protect the elderly 65 years or older is lacking. The significance to nursing is that the study could be used to make a case for continued vaccination campaigns because as the authors point out the seasonal influenza outbreak presents a serious medical challenge that should it go out of hand would result to a substantial burden of disease while causing a serious threat to the global economy. They therefore argue for the continued implementation of the CDC influenza vaccines with the extra recommendation that LAIV vaccine be approved for 65 years and older demographic as it has shown considerable promise in helping reduce fatalities in this group (Vu, Farish, Jenkins, & Kelly, 2002). Comment by Audra Clark: Good implications for nursing Comment by Audra Clark: Be aware of blue lines as they indicate an error

Ethical considerations

The study was not approved by any institutional review board although they declare a no conflict of interest and the sponsors for the study. As it was a meta analyses ethical considerations that had to do with the patient did not come to play however, most of the studies cited had ethical considerations of their own.


In conclusion, the study looks at the overall effectiveness and efficacy of the vaccination campaigns as conducted by the CDC over the years. The researchers note the importance of these campaigns especially given the disease burden and fatalities associated with the flu. To make a case for continued vaccination and to better promote the public interest in the matter, the efficacy and the effectiveness had to be tested and measured. It turns out that there is a case to be made for continued vaccination although the elderly 65 years or older continue to bear a heavier burden than the rest of the population something that could be rectified if a different vaccination method was used.


Good article choice! Your provided a good analysis of the research performed. Would suggest adding a thesis statement in the introduction of your paper and also including headings for better organization – I did add some in red as a suggestion.



Campitelli, M. A., Rosella, L. C., Stukel, T. A., & Kwong, J. C. (2010). Influenza vaccination and all-cause mortality in community-dwelling elderly in Ontario, Canada, a cohort study. Vaccine29(2), 240-246. doi:10.1016/j.vaccine.2010.10.049

Osterholm, M. T., Kelley, N. S., Sommer, A., & Belongia, E. A. (2012). Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis. The Lancet Infectious Diseases12(1), 36-44. doi:10.1016/s1473-3099(11)70295-x

Vu, T., Farish, S., Jenkins, M., & Kelly, H. (2002). A meta-analysis of effectiveness of influenza vaccine in persons aged 65 years and over living in the community. Vaccine20(13-14), 1831-1836. doi:10.1016/s0264-410x (02)00041-5

Also check: Interprofessional Collaboration