Short and long-term safety of the 2009 AS03-adjuvanted pandemic vaccine.

BACKGROUND: This study assessed the short and the long term safety of the 2009 AS03 adjuvanted monovalent pandemic vaccine through an active web-based electronic surveillance. We compared its safety profile to that of the seasonal trivalent inactivated influenza vaccine (TIV) for 2010-2011. METHODOLOGY/PRINCIPAL FINDINGS: Health care workers (HCW) vaccinated in 2009 with the pandemic vaccine (Arepanrix ® from GSK) or HCW vaccinated in 2010 with the 2010-2011 TIV were invited to participate in a web-based active surveillance of vaccine safety. They completed two surveys the day-8 survey covered the first 7 days post-vaccination and the day-29 survey covered events occurring 8 to 28 days after vaccination. Those who reported a problem were called by a nurse to obtain details. The main outcome was the occurrence of a new health problem or the worsening of an existing health condition that resulted in a medical consultation or work absenteeism. For the pandemic vaccine, a six-month follow-up for the occurrence of serious adverse events (SAE) was conducted. Among the 6242 HCW who received the pandemic vaccine, 440 (7%) reported 468 events compared to 328 of the 7645 HCW (4.3%) who reported 339 events after the seasonal vaccine. The 2009 pandemic vaccine was associated with significantly more local reactions than the 2010-2011 seasonal vaccine (1% vs. 0.03%, p<0.001). Paresthesia was reported by 7 HCW (0.1%) after the pandemic vaccine but by none after the seasonal vaccine. For the pandemic vaccine, no clustering of SAE was found in the 6 month follow-up. CONCLUSION: The 2009 pandemic vaccine seems to have a good safety profile, similar to the 2010-2011 TIV, with the exception of local reactions. This surveillance was adequately powered to identify AE associated with an excess risk ≥1 per 1000 vaccinations but is insufficient to detect rare AE. TRIAL REGISTRATION: ClinicalTrials.gov NCT01289418, NCT01318876.

Differential heat shock protein responses to strenuous standardized exercise in chronic fatigue syndrome patients and matched healthy controls.

PURPOSE: Since physical exertion is known to exacerbate the symptoms of chronic fatigue syndrome (CFS) and metabolic changes and including oxidative stress can modulate heat shock protein (HSP) expression responses, we sought to determine whether HSP expression is altered in CFS patients before and after exercise. Heat shock proteins (HSPs) in peripheral blood mononuclear cells (PBMC) were examined from 6 chronic fatigue syndrome (CFS) patients and 7 controls before and after a standardized treadmill exercise. Basal hsp27 was significantly higher among CFS patients compared to controls, and decreased immediately post-exercise, remaining below basal levels even at 7 days. A similar pattern was observed for HSP60, which gradually decreased in CFS patients but increased in controls post-exercise. These findings suggest an abnormal adaptive response to oxidative stress in CFS, and raise the possibility that HSP profiling may provide a more objective biologic marker for this illness. METHODS: HSP27, HSP60, HSP70 and HSP90 expression from 6 CFS patients and 7 age- and sex-matched controls were examined by western blot analysis of peripheral blood mononuclear cells immediately before, after, and at 1 day and 7 days following a standardized treadmill exercise. RESULTS: Basal HSP27 was higher among CFS patients than in controls (0.54 +/- 0.13 vs. 0.19 +/- 0.06, mean +/- SEM; P < 0.01). In addition, these levels in CFS patients decreased immediately post-exercise (0.25 +/- 0.09; P < 0.05) and remained below basal levels at day 1 post-exercises (0.18 +/- 0.05; P < 0.05). P < 0.05). This declining expression of HSP27 during the post-exercise period among CFS patients was confirmed by one-way ANOVA analysis with repeated measures (P < 0.05). In contrast, HSP27 levels remained relatively constant following exercise among control subjects. Similar patterns of declining HSP levels in CFS patients were also observed for HSP60 (0.94 +/- 0.40 vs. 1.32 +/- 0.46; P < 0.05), and for HSP90 (0.34 +/- 0.09 vs. 0.49 +/- 0.10; P < 0.05) at day 7 post-exercise compared with basal levels, respectively. In contrast, HSP60 levels in control subjects increased at day 1 (1.09 +/- 0.27) and day 7 (1.24 +/- 0.50) post-exercise compared to corresponding levels immediately post-exercise (0.55 +/- 0.06) (P < 0.05, respectively). CONCLUSION: These preliminary findings suggest an abnormal or defective adaptive response to oxidative stress in CFS, and raise the possibility that HSP profiling may provide a more objective biologic marker for this illness.

Influenza vaccination: is it appropriate in chronic fatigue syndrome?

Chronic fatigue syndrome (CFS) is a recognized clinical illness of unknown cause and pathophysiologic mechanisms. Immunizing patients against influenza would seem to be a prudent strategy since infection has been associated with symptom exacerbation. However, patients with CFS have demonstrated variable abnormalities in the immune system, the clinical significance of which is unclear. Anecdotal information has suggested that, due to the etiologic uncertainty surrounding CFS, many patients reject immunization, fearful of untoward effects. This article attempts to clarify the situation by reviewing immunologic findings in CFS and influenza vaccines in current use. Results from a recent survey of perceptions of patients with CFS regarding immunization revealed that 31% felt immunization was neither safe nor beneficial. This opinion was universal in those patients who had never received influenza vaccine. Among patients who had received vaccine and experienced an adverse effect, 26% felt the vaccine was safe and 28% felt it was beneficial. Among those who had received vaccine without an adverse effect, 45% believed the vaccine was safe, and 55% felt it was effective. CFS patients as a group expressed concern that influenza vaccine would alter an already dysfunctional immune system, or worsen CFS symptoms. Significantly more patients with CFS who had never received influenza vaccine voiced this opinion than did patients who had received immunization for influenza in the past. Contrary to the opinions expressed by the sample, clinical trials in CFS have yet to find that any type of immunization has produced a deleterious effect on symptoms or functioning. Moreover, patients with CFS in a randomized, placebo-controlled, double-blind trial of influenza immunization produced an antibody titer in the protective range to inactivated trivalent influenza vaccine, although the geometric mean titer was slightly blunted compared with healthy vaccinees. Although patients with CFS in placebo and active groups reported four times the number of post-injection adverse effects of healthy vaccinees, data re-analysis revealed that this finding was related to the overlap of common, post-influenza immunization symptoms and CFS constitutional symptoms. CFS is a poorly understood illness and some patients may believe in causal theories that lead to the rejection of disease prevention strategies such as immunization. However, influenza immunization appears to provide protective antibody levels without worsening CFS symptoms or causing excessive adverse effects. Efforts to motivate patients with CFS to obtain annual influenza immunization should take into account illness perceptions and concentrate on education based on placebo-controlled trials.