Partial vaccination was not effective on children 6-23 months. This meant that full vaccination is necessary to optimally protect children of this age group from Influenza (Shueler et al.).
The results are consistent with those of other evaluative studies on children through randomized, controlled trials for efficacy and observational studies for effectiveness (Shueler et al., 2007). Vaccine effectiveness depends on the characteristics of the study population, specificity of the outcome, and the Influenza season. It was dissimilar to the findings of Ritzwoller and his team in that Shueler and team's subjects had more exposure to Influenza. The more specific outcome of laboratory-confirmed Influenza made the detection possible. And Shueler and his team's findings were similar to Ritzwoller and his team's in that the findings of both teams offered assurance that vaccination of young children would be beneficial, even in a year with sub-optimal match (Shueler et al.).
Vaccination Efficacy not Found
A case -- cohort study aimed at measuring vaccination among children aged 6-59 months during 2 Influenza seasons (Szilagyi et al., 2008). Participating patients were 165 and 80 inpatient/emergency department and 74 and 95 outpatient Influenza cases. Another group of 4,500 inpatient/ED and more than 600 outpatient sub-cohorts, respectively, were also evaluated. The team compared vaccination status of laboratory-confirmed Influenza cases with random sales in 3 counties during the 2 seasons. Results showed that vaccine effectiveness could not be determined for any season, age or setting after adjusting for county, sex, insurance, chronic conditions and timing of vaccination. The case-cohort research design might be inefficient and insufficiently account for important factors, like the inclination to obtain care. The team concluded that further studies should be conducted using other designs to evaluate the yearly impact of Influenza vaccination programs for children (Szilagyi et al.).
Live Attenuated Influenza Vaccine or LAIV
This is the approved vaccine in the United States for persons aged 2-49 (Ambrose et al., 2008). It is administered as an intranasal spray. It has provided high levels of efficacy in both match and mismatched strains in this age group. Comparative studies between LAIV and inactivated Influenza vaccine in children showed that patients with LAIV had up to 53% fewer cases of illness than with the other vaccine. The most common adverse reactions are runny nose or nasal congestion in the said age group and less than 100 degrees Fahrenheit fever in children. Formulations of LAIV are under experiment (Ambrose et al.).
Live attenuated Influenza viruses replicate primarily in the nose and throat area to induce the body's immune response (Ambrose et al., 2008). These viruses do not replicate too well in lower airways and lung where the temperature is warmer. During replication, viral proteins will be perceived by the immune system, which responds to natural infection by Influenza viruses. The vaccine is now currently approved for children 2 years old and older. Tests showed up to 93.4% efficacy against illness after the first year of vaccination. It reached 100% after the second year. LAIV also protects against antigenically mismatched strains as a single dose in children 1.5 to 18 years of age. As to dose, tests showed that a single dose had a 58% efficacy while two doses had 89%. Thus, the recommended dose is 2. The vaccine was also evaluated as safe in more than 18,000 tested children less than 5 years old except for nasal congestion or runny nose (Ambrose et al.).
There is concern about these viruses re-assorting with circulating seasonal Influenza viruses and evolve into easily transmissible types (Ambrose et al., 2008). Authorities addressed this concern by conducting clinical trials during months when the viruses are not likely to circulate. This can be done in an isolation facility between April and December. When a pandemic is imminent, the risks should be weighed against the benefits before the massive use of the vaccine. This will be the decision of public health authorities (Ambrose et al.).
Feasibility and Physicians' View of Influenza Vaccines
A national random study was conducted in February 2001 with 458 pediatricians and family physicians on the feasibility of routine Influenza vaccination of infants and toddlers (Humiston et al., 2004). It also determined the potential barriers to it and its current and projected use. The survey focused primarily on routine Influenza vaccination for children 12-35 months in injection or intranasal spray vaccine form (Humiston et al.).
Most of the respondent physicians agreed that vaccination was feasible at 80% and that it would significantly reduce visits for illness during the Influenza season at 69-80% (Humiston et al., 2004). They favored vaccination for children 12 through 35 months old in the form of an injection or intranasal vaccine. They did not favor administering to children less than 1-year of age. They also believed vaccination should be administered in the primary care office during well-child care visits. However, incorporating the Influenza vaccine into routine well-child care involves an additional vaccination into an already crowded schedule (Humiston et al.).
The surveyed physicians also identified major barriers to the vaccination as costs, parental concerns over safety and the hassle of another vaccination or visits (Humiston et al., 2004). The American Academy of Pediatrics Committee listed logistics constraints to vaccinating healthy children as including limited vaccine quantity, seasonal availability, and liability concerns. These concerns included multiple injections, complicated schedule, recall systems, personal requirements, and reimbursement. Pediatricians favored universal Influenza vaccination more than family physicians on the basis of specialization. Their respective beliefs about disease burden, vaccine effectiveness, feasibility, and parental interest in the vaccine influenced their positions. Primary care physicians favored expanded Influenza vaccination and recommended covering healthy children aged 12-35 months. They saw the administering of intranasal spray vaccine on infants as a concern. Physicians, on the other hand, recommended ways of making widespread of universal vaccination feasible. These were minimizing family out-of-pocket costs and reimbursing them for these; educational campaigns on the collective and recent evidence of disease burden and the effectiveness and safety of the vaccine; and changes in the systems within primary care office, including tracking down eligible children, reminder-recall systems, and immunization clinics or alternative methods in handling large volumes of visits during vaccination seasons (Humiston et al.).
Children are the most appropriate object of an Influenza vaccine because they belong to one of two most vulnerable groups to Influenza infection, which recently has reached epidemic proportions. The CDCP and internationally recognized bodies recommend immunization or vaccination in children as a public health measure (Jefferson, 2009). Various and recent studies showed that live vaccines in 2 doses as a nasal spray provide high-level protection and safety in healthy children 2 years old and older with minimal adverse reactions. Most surveyed physicians agreed that it is desirable and feasible, if certain concerns are adequately addressed (Humiston et al., 2004). #
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