Dynamics of anti-Spike IgG antibody level after full BNT162b2 COVID-19 vaccination in health care workers

IntroductionThe administration of a third vaccine is ongoing in many countries, but the evaluation of vaccine-induced immunity is still insufficient. This study evaluated anti-spike IgG levels in 373 health care workers six months after the BNT162b2 vaccination. MethodsDynamics of anti-spike IgG levels six months after the 2nd vaccination were assessed in 49 participants (Analysis-1). A cross-sectional assessment of anti-spike IgG level was performed in 373 participants (Analysis-2). Participants positive for anti-nucleocapsid IgG or IgM and receiving immunosuppressants were excluded from Analysis-2. ResultsIn Analysis 1, the median anti-spike IgG level was lower in the older age group and decreased consistently after the second vaccination regardless of age. In Analysis-2, the anti-spike IgG level was significantly negatively associated with age (r = -0.35, p < 0.01). This correlation remained statistically significant (r = -0.28, p < 0.01) even after adjusting for sex, BMI, smoking habits, alcohol drinking habits, allergies, and the presence of fever or other adverse reactions at the time of the vaccination. Alcohol drinking habit was also associated with the anti-spike IgG level; daily alcohol drinkers had significantly lower anti-spike IgG levels than never alcohol drinkers. Sex, smoking habit, allergy, and fever and other side effects after the vaccination were not associated with anti-spike IgG levels six months after the 2nd vaccination. ConclusionsSix months after the vaccination, the anti-spike IgG level was substantially low among older persons and daily alcohol drinkers.

Efficacy of Influenza Vaccine among Elderly Patients by Physical Activity Status

Objective: Although many studies have shown the usefulness of influenza vaccine in elderly in-patients, the efficacy of vaccination with regard to the daily physical activities of patients has not been fully evaluated. To address this issue, we correlated the use of medical resources with vaccination status in patients categorized according to their daily activity levels. Methods: The subjects comprised 237 in-patients at or above 51 years of age, who were hospitalized in the long-term care unit of a Japanese hospital between January and March, 1999. The vaccination status and medical resources use (i.e., oral antibiotics, injected antibiotics, blood cell count, chest X-ray) of each patient were recorded, and the patients were assigned to three subgroups, based on daily life activity scores. Results: Vaccinated in-patients in the ‘bed-bound’ category required fewer medical resources, i.e., oral antibiotics (−2.29 days, P<0.05), injected antibiotics (−5.02 days, P<0.001), blood cell counts (−4.66 times, P<0.001), and chest X-rays (−4.31 times, P<0.001), compared with unvaccinated in-patients. There were no significant differences in treatment parameters between vaccinated and unvaccinated patients in the ‘partly limited’ or ‘no limitation’ categories. Conclusions: It is suggested that influenza vaccination significantly reduces the need for medical treatment only among those in-patients who are the least physically active. Further studies are required to replicate these findings, and to elucidate the underlying reasons for this reduction.

Efficacy of influenza vaccine among elderly patients by physical activity status

<p><b>OBJECTIVE</b>Although many studies have shown the usefulness of influenza vaccine in elderly in-patients, the efficacy of vaccination with regard to the daily physical activities of patients has not been fully evaluated. To address this issue, we correlated the use of medical resources with vaccination status in patients categorized according to their daily activity levels.</p><p><b>METHODS</b>The subjects comprised 237 in-patients at or above 51 years of age, who were hospitalized in the long-term care unit of a Japanese hospital between January and March, 1999. The vaccination status and medical resources use (i.e., oral antibiotics, injected antibiotics, blood cell count, chest X-ray) of each patient were recorded, and the patients were assigned to three subgroups, based on daily life activity scores.</p><p><b>RESULTS</b>Vaccinated in-patients in the 'bed-bound' category required fewer medical resources, i.e., oral antibiotics (-2.29 days,P<0.05), injected antibiotics (-5.02 days,P<0.001), blood cell counts (-4.66 times,P<0.001), and chest X-rays (-4.31 times,P<0.001), compared with unvaccinated in-patients. There were no significant differences in treatment parameters between vaccinated and unvaccinated patients in the 'partly limited' or 'no limitation' categories.</p><p><b>CONCLUSIONS</b>It is suggested that influenza vaccination significantly reduces the need for medical treatment only among those in-patients who are the least physically active. Further studies are required to replicate these findings, and to elucidate the underlying reasons for this reduction.</p>