Cross-Protective Immune Responses Elicited by Live Attenuated Influenza Vaccines

The desired effect of vaccination is to elicit protective immune responses against infection with pathogenic agents. An inactivated influenza vaccine is able to induce the neutralizing antibodies directed primarily against two surface antigens, hemagglutinin and neuraminidase. These two antigens undergo frequent antigenic drift and hence necessitate the annual update of a new vaccine strain. Besides the antigenic drift, the unpredictable emergence of the pandemic influenza strain, as seen in the 2009 pandemic H1N1, underscores the development of a new influenza vaccine that elicits broadly protective immunity against the diverse influenza strains. Cold-adapted live attenuated influenza vaccines (CAIVs) are advocated as a more appropriate strategy for cross-protection than inactivated vaccines and extensive studies have been conducted to address the issues in animal models. Here, we briefly describe experimental and clinical evidence for cross-protection by the CAIVs against antigenically distant strains and discuss possible explanations for cross-protective immune responses afforded by CAIVs. Potential barriers to the achievement of a universal influenza vaccine are also discussed, which will provide useful guidelines for future research on designing an ideal influenza vaccine with broad protection without causing pathogenic effects such as autoimmunity or attrition of protective immunity against homologous infection.

Toward a universal influenza vaccine: from the perspective of protective efficacy

No abstract available.

Principles underlying rational design of live attenuated influenza vaccines

Despite recent innovative advances in molecular virology and the developments of vaccines, influenza virus remains a serious burden for human health. Vaccination has been considered a primary countermeasure for prevention of influenza infection. Live attenuated influenza vaccines (LAIVs) are particularly attracting attention as an effective strategy due to several advantages over inactivated vaccines. Cold-adaptation, as a classical means for attenuating viral virulence, has been successfully used for generating safe and effective donor strains of LAIVs against seasonal epidemics and occasional pandemics. Recently, the advent of reverse genetics technique expedited a variety of rational strategies to broaden the pool of LAIVs. Considering the breadth of antigenic diversity of influenza virus, the pool of LAIVs is likely to equip us with better options for controlling influenza pandemics. With a brief reflection on classical attenuating strategies used at the initial stage of development of LAIVs, especially on the principles underlying the development of cold-adapted LAIVs, we further discuss and outline other attenuation strategies especially with respect to the rationales for attenuation, and their practicality for mass production. Finally, we propose important considerations for a rational vaccine design, which will provide us with practical guidelines for improving the safety and effectiveness of LAIVs.

Effect of Hot Pack Therapy on the Blood Flow of Lower Extremities

OBJECTIVE: To evaluate quantitative changes in arterial blood flow in the legs and systemic changes in blood flow after hot pack therapy on a leg. METHOD: It was conducted on 60 legs of 30 adults without the symptom of peripheral vascular disease. The blood flow of both popliteal arteries were recorded before and after hot pack therapy on a leg. Also, the blood pressure and pulse rate were recorded every two minutes using a pulsimeter. T-test was done to examine differences between blood flow of the popliteal artery on both legs before and after hot pack therapy. Paired t-test was used to examine differences in each leg before and after hot pack therapy and systemic effect after hot pack therapy. RESULTS: After hot pack therapy, there were statistically meaningful changes in all the variables except the popliteal arterial diameter in a leg with hot pack therapy, whereas there were no significantly meaningful changes in a leg without therapy. Pulse rate was changed significantly, but blood pressures were not. CONCLUSION: There were an increase in regional arterial blood velocity and blood flow, skin temperature, and a reduction in peripheral resistance in a leg with hot pack therapy, but no meaningful changes without thrapy. There is no evidence of reflex vasodilatation. There is no meaningful changes in blood pressure, but an increase in pulse rate.

Reliability and Validity of Korean Version of National Institutes of Health Stroke Scale: Multi-center study

OBJECTIVE: To assess the inter-tester and test-retest reliability and validity after developing of Korean version of National Institutes of Health Stroke Scale (NIHSS). METHOD: This research was conducted on 27 patents with stroke with less than 12 months since the onset of disease. Five physiatrists translated NIHSS into Korean. Video taping were used for objective scorings. Four physiatrists conducted scorings in order to seek for inter-tester reliability and one conducted scorings three weeks interval for test-retest reliability. Six physiatrists conducted scorings in order to seek for concurrent validity with the original NIHSS and four conducted scorings for validity with other impairment scale. Each score was analyzed based on Spear-man correlation coefficient. RESULTS: According to inter-tester reliability for Korean version of NIHSS, rho value reached over 0.70, with over 0.72 concerning test-retest reliability. The test on concurrent validity with the original NIHSS reached over 0.70 at rho value, with over 0.653 for MMSE, Motricity index, Brunnstrom stage. CONCLUSION: Newly developed Korean version of NIHSS showed high inter-tester and test-retest reliabilities, together with high concurrent validity with the original and other impairment scales, to be regarded to be used as primary impairment scale for patients with stroke.