Antibodies Induced by Smallpox Vaccination after at Least 45 Years Cross-React with and In Vitro Neutralize Mpox Virus: A Role for Polyclonal B Cell Activation?

AIMS: To evaluate whether antibodies specific for the vaccinia virus (VV) are still detectable after at least 45 years from immunization. To confirm that VV-specific antibodies are endowed with the capacity to neutralize Mpox virus (MPXV) in vitro. To test a possible role of polyclonal non-specific activation in the maintenance of immunologic memory. METHODS: Sera were collected from the following groups: smallpox-vaccinated individuals with or without latent tuberculosis infection (LTBI), unvaccinated donors, and convalescent individuals after MPXV infection. Supernatant of VV- or MPXV-infected Vero cells were inactivated and used as antigens in ELISA or in Western blot (WB) analyses. An MPXV plaque reduction neutralization test (PRNT) was optimized and performed on study samples. VV- and PPD-specific memory T cells were measured by flow cytometry. RESULTS: None of the smallpox unvaccinated donors tested positive in ELISA or WB analysis and their sera were unable to neutralize MPXV in vitro. Sera from all the individuals convalescing from an MPXV infection tested positive for anti-VV or MPXV IgG with high titers and showed MPXV in vitro neutralization capacity. Sera from most of the vaccinated individuals showed IgG anti-VV and anti-MPXV at high titers. WB analyses showed that positive sera from vaccinated or convalescent individuals recognized both VV and MPXV antigens. Higher VV-specific IgG titer and specific T cells were observed in LTBI individuals. CONCLUSIONS: ELISA and WB performed using supernatant of VV- or MPXV-infected cells are suitable to identify individuals vaccinated against smallpox at more than 45 years from immunization and individuals convalescing from a recent MPXV infection. ELISA and WB results show a good correlation with PRNT. Data confirm that a smallpox vaccination induces a long-lasting memory in terms of specific IgG and that antibodies raised against VV may neutralize MPXV in vitro. Finally, higher titers of VV-specific antibodies and higher frequency of VV-specific memory T cells in LTBI individuals suggest a role of polyclonal non-specific activation in the maintenance of immunologic memory.

Have Diagnostics, Therapies, and Vaccines Made the Difference in the Pandemic Evolution of COVID-19 in Comparison with "Spanish Flu"?

In 1918 many countries, but not Spain, were fighting World War I. Spanish press could report about the diffusion and severity of a new infection without censorship for the first-time, so that this pandemic is commonly defined as "Spanish flu", even though Spain was not its place of origin. "Spanish flu" was one of the deadliest pandemics in history and has been frequently compared with the coronavirus disease (COVID)-19 pandemic. These pandemics share similarities, being both caused by highly variable and transmissible respiratory RNA viruses, and diversity, represented by diagnostics, therapies, and especially vaccines, which were made rapidly available for COVID-19, but not for "Spanish flu". Most comparison studies have been carried out in the first period of COVID-19, when these resources were either not yet available or their use had not long started. Conversely, we wanted to analyze the role that the advanced diagnostics, anti-viral agents, including monoclonal antibodies, and innovative COVID-19 vaccines, may have had in the pandemic containment. Early diagnosis, therapies, and anti-COVID-19 vaccines have markedly reduced the pandemic severity and mortality, thus preventing the collapse of the public health services. However, their influence on the reduction of infections and re-infections, thus on the transition from pandemic to endemic condition, appears to be of minor relevance. The high viral variability of influenza and coronavirus may probably be contained by the development of universal vaccines, which are not easy to be obtained. The only effective weapon still remains the disease prevention, to be achieved with the reduction of promiscuity between the animal reservoirs of these zoonotic diseases and humans.

A Historical Review of Military Medical Strategies for Fighting Infectious Diseases: From Battlefields to Global Health.

The environmental conditions generated by war and characterized by poverty, undernutrition, stress, difficult access to safe water and food as well as lack of environmental and personal hygiene favor the spread of many infectious diseases. Epidemic typhus, plague, malaria, cholera, typhoid fever, hepatitis, tetanus, and smallpox have nearly constantly accompanied wars, frequently deeply conditioning the outcome of battles/wars more than weapons and military strategy. At the end of the nineteenth century, with the birth of bacteriology, military medical researchers in Germany, the United Kingdom, and France were active in discovering the etiological agents of some diseases and in developing preventive vaccines. Emil von Behring, Ronald Ross and Charles Laveran, who were or served as military physicians, won the first, the second, and the seventh Nobel Prize for Physiology or Medicine for discovering passive anti-diphtheria/tetanus immunotherapy and for identifying mosquito Anopheline as a malaria vector and plasmodium as its etiological agent, respectively. Meanwhile, Major Walter Reed in the United States of America discovered the mosquito vector of yellow fever, thus paving the way for its prevention by vector control. In this work, the military relevance of some vaccine-preventable and non-vaccine-preventable infectious diseases, as well as of biological weapons, and the military contributions to their control will be described. Currently, the civil-military medical collaboration is getting closer and becoming interdependent, from research and development for the prevention of infectious diseases to disasters and emergencies management, as recently demonstrated in Ebola and Zika outbreaks and the COVID-19 pandemic, even with the high biocontainment aeromedical evacuation, in a sort of global health diplomacy.

Immunogenicity of Viral Vaccines in the Italian Military.

Military personnel of all armed forces receive multiple vaccinations and have been doing so since long ago, but relatively few studies have investigated the possible negative or positive interference of simultaneous vaccinations. As a contribution to fill this gap, we analyzed the response to the live trivalent measles/mumps/rubella (MMR), the inactivated hepatitis A virus (HAV), the inactivated trivalent polio, and the trivalent subunits influenza vaccines in two cohorts of Italian military personnel. The first cohort was represented by 108 students from military schools and the second by 72 soldiers engaged in a nine-month mission abroad. MMR and HAV vaccines had never been administered before, whereas inactivated polio was administered to adults primed at infancy with a live trivalent oral polio vaccine. Accordingly, nearly all subjects had baseline antibodies to polio types 1 and 3, but unexpectedly, anti-measles/-mumps/-rubella antibodies were present in 82%, 82%, and 73.5% of subjects, respectively (43% for all of the antigens). Finally, anti-HAV antibodies were detectable in 14% and anti-influenza (H1/H3/B) in 18% of the study population. At mine months post-vaccination, 92% of subjects had protective antibody levels for all MMR antigens, 96% for HAV, 69% for the three influenza antigens, and 100% for polio types 1 and 3. An inverse relationship between baseline and post-vaccination antibody levels was noticed with all the vaccines. An excellent vaccine immunogenicity, a calculated long antibody persistence, and apparent lack of vaccine interference were observed.

Safety of Multiple Vaccinations and Durability of Vaccine-Induced Antibodies in an Italian Military Cohort 5 Years after Immunization.

We previously examined the safety and immunogenicity of multiple vaccines administered to a military cohort, divided into two groups, the first composed of students at military schools, thus operating inside the national borders for at least 3 years, and the other formed of soldiers periodically engaged in a 9-month-long mission abroad (Lebanon). In the current study, we analyzed 112 individuals of this cohort, 50 pertaining to the first group and 62 to the second group, in order to examine the possible late appearance of side effects and to calculate the half-life of the induced antibodies. Moreover, the possible involvement of B-cell polyclonal activation as a pathogenetic mechanism for long term antibody persistence has even been explored. No late side effects, as far as autoimmunity and/or lymphoproliferation appearance, have been noticed. The long duration of the vaccine induced anti-HAV antibodies has been confirmed, whereas the antibodies induced by tetravalent meningococcal polysaccharide vaccine have been found to persist above the threshold for putative protection for a longer time, and anti-tetanus, diphtheria, and polio 1 and 3 for a shorter time than previously estimated. No signs of polyclonal B-cell activation have been found, as a possible mechanism to understand the long antibody persistence.

High Prevalence of Spinal Magnetic Resonance Imaging Findings in Asymptomatic Young Adults (18-22 Yrs) Candidate to Air Force Flight.

STUDY DESIGN: Cross-sectional, retrospective, magnetic resonance (MR) imaging study, performed during cadets' selection procedures of the Italian Air Force Academy. OBJECTIVE: To assess the prevalence of spinal MR imaging findings in asymptomatic young adults (18-22 yrs) candidate to Air Force Flight. SUMMARY OF BACKGROUND DATA: Spinal MR imaging findings are frequently detected in asymptomatic subjects. Literature prevalence data come from studies that analyze different patient populations, in a wide age range and in different spinal tracts. Chronic degenerative disease of the vertebral column often occurs in pilots exposed to high flight acceleration forces, thus resulting crucial for Air Force Academy to exclude vertebral disease in cadets. METHODS: Three hundred fifty asymptomatic young adults underwent a 3T MR examination of the entire spine. A structured radiological report was set up to classify and calculate the prevalence of spinal MR imaging findings. RESULTS: Two hundred seventy of 350 subjects (77%) presented spinal MR findings, while 80 of 350 candidates (23%) had no detectable MR imaging findings. One hundred six of 350 (30%) candidates had at least one disc desiccation and 47 of 350 (13%) presented at least one disc narrowing. Disc bulging was found in 176 of 350 (49%) cadets. Sixty-two of 350 (18%) subjects showed disc protrusion while 28 of 350 (8%) had disc extrusion. Forty-five of 350 (13%) candidates presented low grade intervertebral spondylosis and of these 12 had also facet joints spondylosis. Asymptomatic vertebral fractures were observed in 2 of 350 (<1%) cadets. CONCLUSION: A high rate of MR spinal imaging findings, similar to that of the adult population, was detected in our population of young asymptomatic subjects. Our results suggest that the process of aging spine, which is supposed to begin in the second decade of life, is morphologically appreciable in the immediate postadolescent period and this issue is of crucial importance when selecting military pilots. LEVEL OF EVIDENCE: 4.

Tetanus-diphtheria vaccination in adults: the long-term persistence of antibodies is not dependent on polyclonal B-cell activation and the defective response to diphtheria toxoid re-vaccination is associated to HLADRB1∗01.

Cellular and humoral immune responses to tetanus-diphtheria vaccine (Td) were assessed in human leukocyte antigen (HLA)-typed Italian military personnel who received multiple concomitant vaccines. Td-specific antibodies and T-lymphocytes were measured in individuals with one (group-1) and more than one (group-2) Td boosters. A third group (group-3), who received several vaccines, but not Td, was studied to verify the hypothesis of the polyclonal B-cell activation as mechanism for antibody persistence. The antibody response to Td toxoids was higher in group-1, who showed lower baseline antibody levels, than in group-2 subjects. The antibody response to tetanus was higher than to diphtheria toxoid in both groups. No correlation between antibody and cellular response, and no interference in the response to Td by co-administration of different vaccines were observed. HLA-DRB1∗01 allele was detected at significant higher frequency in subjects unable to double the baseline anti-diphtheria antibody levels after the vaccination. Anti-tetanus and diphtheria antibodies half-lives were assessed and the long-lasting persistence above the threshold for protection (0.1 IU/ml) was estimated in over 65 and 20 years, respectively. No significant increase of anti-diphtheria antibodies was observed in consequence of polyclonal B-cell activation. This study emphasizes the duration of Td vaccination-induced seroprotection, suggesting that re-vaccination should probably be performed at intervals longer than 10 years. No reciprocal interference by concomitantly administered vaccines has been observed. HLA-DRB1∗01 allele was significantly associated with anti-diphtheria defective response. Finally, this study does not confirm that anti-diphtheria antibody levels are maintained by polyclonal B-cell activation. Clinical trial registry: The study was registered with NCT01807780.

Lack of evidence for post-vaccine onset of autoimmune/lymphoproliferative disorders, during a nine-month follow-up in multiply vaccinated Italian military personnel.

Anecdotal case reports, amplified by mass media and internet-based opinion groups, have recently indicated vaccinations as possibly responsible for autoimmunity/lymphoproliferation development. Multiply vaccinated Italian military personnel (group 1, operating in Italy, group 2, operating in Lebanon) were followed-up for nine months to monitor possible post-vaccine autoimmunity/lymphoproliferation onset. No serious adverse event was noticed in both groups. Multivariate analysis of intergroup differences only showed a significant association between lymphocyte increase and tetanus/diphtheria vaccine administration. A significant post-vaccine decrease in autoantibody positivity was observed. Autoantibodies were also studied by microarray analysis of self-proteins in subjects exposed to ≥4 concurrent vaccinations, without observing significant difference among baseline and one and nine months post-vaccine. Moreover, HLA-A2 subjects have been analyzed for the possible CD8T-cell response to apoptotic self-epitopes, without observing significant difference between baseline and one month post-vaccine. Multiple vaccinations in young adults are safe and not associated to autoimmunity/lymphoproliferation onset during a nine-month-long follow-up.

Motion Sickness Prediction in Aeromedical Evacuation of Patients with Ebola.

INTRODUCTION: Aeromedical evacuation of patients affected by severe infectious diseases inside an aircraft transit isolator (ATI) system is at potential risk of motion sickness (MS). A test flight was then conducted to quantify this risk during the transfer of an Ebola patient from West Africa to Italy. CASE REPORT: A mannequin was inserted inside an ATI and instrumented to provide acceleration parameters throughout the test flight. The analysis of the data predicted a MS incidence of about 2% for a 6-h flight, so the decision to use anti-MS drugs only in selected cases was taken (i.e., those with positive past history of MS, gastrointestinal disorders, or residual carsickness due to previous ambulance run). On this basis, an actual aeromedical evacuation of an Ebola patient was successfully performed without the use of any anti-MS drugs. DISCUSSION: During aeromedical evacuation with ATI systems, the patient's risk of MS should be evaluated on an individual basis and calibrated according to the specific exposure to motion evoked by the flight platform used. Due to the possible onset of untoward effects, prevention with anti-MS drugs in these patients should be limited to selected cases.

Mortality in Italian veterans deployed in Bosnia-Herzegovina and Kosovo.

BACKGROUND AND AIMS: The possible increase of cancer risk in military personnel deployed in Balkans during and after the 1992-1999 wars, mainly related to the depleted uranium, was addressed by several studies on European veterans of those war theatres. This article reports on the results of the mortality study on the Italian cohort of Bosnia and Kosovo veterans (Balkan cohort). METHODS: Mortality rates for the Balkan cohort (71 144 persons) were compared with those of the Italian general population as well as to those of a comparable and unselected control cohort of not deployed military personnel (114 269 persons). Ascertainment of vital status during the period 1995-2008 of all the persons in the two cohorts has been carried out through deterministic record linkage with the national death records database, from information provided by the respective Armed Force General Staff, and through the civil registry offices of the veterans' residence or birth municipalities. RESULTS: The Balkan cohort experienced a mortality rates lower than both the general population (SMR = 0.56; 95% CI 0.51-0.62) and the control group (SMR = 0.88; 95% CI 0.79-0.97). Cancer mortality in the deployed cohort group was half of that from the general population mortality rates (SMR = 0.50; 95% CI 0.40-0.62) and slightly lower if compared with the control group cancer mortality rates (SMR = 0.95; 95% CI 0.77-1.18). CONCLUSION: Balkan veteran cohort did not show any increase in general mortality or in cancer mortality.

Acute hypobaric-hypoxia challenge and salivary cortisol and DHEA-S in healthy male subjects.

BACKGROUND: Hypobaric hypoxia is a stressful emergency situation that can cause a degradation of the sensory, motor, and higher cognitive functions necessary for safe flight. METHODS: We studied the salivary cortisol and dehydroepiandrosterone-sulfate (DHEA-S) concentrations of 12 healthy male military aviators (AV) exposed to an altitude-induced hypoxia challenge in a hypobaric chamber. A matched control group (C) of eight flight physiology instructors wearing oxygen masks during the challenge was studied. Salivary samples were collected every 2 h on 3 experimental days (the day before, the day of, and the day after the hypobaric chamber challenge). RESULTS: In the AV group, salivary cortisol concentrations showed a statistically significant increase from 5.42 +/- 0.15 measured at 08:30 to 11.37 +/- 1.86 ng ml(-1) during the hypobaric chamber challenge and a statistically significant increase in DHEA-S was also measured (from 3.15 +/- 0.42 ng x ml(-1) at 08:30 to 5.99 +/- 0.15 ng x ml(-1)). The day after the challenge, the concentrations of both hormones were comparable to those measured the day before; neither C nor AV showed any disturbances of the physiological diurnal fluctuations of cortisol and DHEA-S. No differences were found among the cortisol/DHEA-S ratios measured during the 3 experimental days in the AV group. DISCUSSION: In spite of having experienced a psycho-physical stress, the AVs did not show any dysregulation of the diurnal fluctuations of cortisol and DHEA-S, thus presenting a good level of stress resilience. Data presented in this paper are consistent with recent literature suggesting a stress-buffering role of DHEA-S.

Stress-induced salivary cortisol secretion during hypobaric hypoxia challenge and in vivo urinary thromboxane production in healthy male subjects.

Few studies have assessed the effects of stress on in vivo platelet activation. In the present study, hypobaric hypoxia induced by rapid decompression during high-altitude simulated flight in a hypobaric chamber was used to evaluate the effects of environmental stress on salivary cortisol and urinary thromboxane metabolite (TXM) excretion, a noninvasive marker of in vivo platelet function. Twenty-one male aviators (mean ± SD age = 36 ± 7 years) experiencing hypoxia by removing their oxygen mask for 4-5 min during a simulated flight to 25,000 ft (7,620 m; pO(2) = 59.17 mmHg) and a matched control group of thirteen flying instructors wearing oxygen masks during the challenge, were studied. Hypobaric hypoxia induced a transient significant increase (P < 0.001) in the aviators' salivary cortisol concentration; the overall pattern of diurnal cortisol fluctuation was maintained in both groups. Urinary TXM showed a significant ∼30% reduction (P < 0.01) after the chamber session in aviators exposed to hypobaric hypoxia, but not in controls. A significant inverse correlation was found between salivary cortisol and urinary TXM in aviators (r = - 0.64, P = 0.0015). Salivary cortisol was a significant predictor (P < 0.001) for urinary TXM concentrations in aviators. In conclusion, here we observed that an acute stress-induced salivary cortisol increase was associated with reduced urinary thromboxane biosynthesis, providing the first indirect evidence for an inhibitory effect of acute stress on in vivo platelet function.

Wolman disease and cholesteryl ester storage disease diagnosed by histological and ultrastructural examination of intestinal and liver biopsy.

Deficient activity of lysosomal acid lipase (LAL) results in massive accumulation of cholesteryl esters and triglycerides in most tissues of the body. The deficiency state is expressed in two major phenotypes: Wolman disease (WD) and cholesteryl ester storage disease (CESD). WD occurs in infancy and is nearly always fatal before the age of 1 year, whereas CESD can be more benign and may not be detected until adulthood. Since there are no specific routine laboratory observations that suggest these metabolic diseases, diagnosis is based on the clinical picture combined with LAL deficiency in cultured skin fibroblasts or peripheral lymphocytes. Both disorders are rather rare, considering that about a hundred of cases have been described up to now. This study describes the histological and ultrastructural aspects disclosed by intestinal or liver biopsy in three cases of WD and in two cases of CESD. Furthermore, it emphasizes the role of morphological findings in pointing the diagnosis towards a metabolic storage disease.

Effects of mental stress on cardiovascular and endocrine response in Air Force Academy cadets.

OBJECTIVES: Pilots are exposed to the "stress of flight" and the chronically activated stress response may play an important role in circulatory system disease progression. We studied the effect of an experimental mental stress on cardiovascular and neuroendocrine activity, in Air Force Academy cadets, before and after one month intensive course. DESIGN: Nine cadets were submitted to a psychometric evaluation before Stroop test (ST), including Minnesota Multiphasic Personality Inventory, State and Trait Anxiety Inventory (STAI X1 and X2 form) and Reaction Scheme Test. After ST, subjects completed a STAI X1 form. Heart rate (HR), systolic and diastolic blood pressure (SBP and DBP) were monitored and serum prolactin (PRL), growth hormone (GH), adrenocorticotropin (ACTH) and cortisol levels were determined, during ST. The protocol was repeated at the end of the course. RESULTS: No significant differences were evident in PRL, GH and ACTH levels. Cortisol concentrations were significantly higher before the course. ST did not modify hormone secretion. ST induced a significant and reproducible elevation of HR and SBP. Basal HR, SBP and DBP values were significantly elevated after the course. Two subjects presented a particular psychometric profile, a different cardiovascular response to ST and did not pass the course. CONCLUSIONS: acute mental stress significantly activated cardiovascular response without modifying endocrine responses, in relation to the psychological profiles. A significant increase of cardiovascular parameters was present after the course, with enhanced dichotomy between the endocrine and sympathetic system, suggesting a careful evaluation and follow-up for circulatory system diseases in cadets.

Vaccination policies in the military: an insight on influenza.

Influenza, despite its generally benign clinical course, is accompanied by absenteeism from work, acute suffering and even mortality, mainly in the elderly and in subjects who have high-risk medical conditions. Its prevention consists of strain specific vaccination, which must be repeated annually due to the high antigenic variability of the influenza virus. Influenza may represent an important obstacle to military readiness, particularly when considering its infectivity within closed communities. Despite such epidemiological situations, influenza vaccination is seldom included in the compulsory vaccination programme of the military on a global level. This may be due to several reasons, namely, a lack of confidence in the vaccine's effectiveness, the need for annual administrations (with expansion of economic and organisational efforts), false assumption that influenza is a disease with a minor impact, contradictory results of cost-effectiveness analyses (examples of which have yet to be made specifically for the military environment). The availability of more effective, economic and easy to administer vaccines, together with detailed and tailored cost-effectiveness analyses, may have a beneficial effect on the role the military plays in the fight against influenza across the globe.

Nephroblastoma. DNA characteristics and their modifications induced by prenephrectomy chemotherapy: a cytofluorimetric study.

Treatment of nephroblastoma (Wilms' tumor) has presently achieved a 90% survival rate. Stage and grade are considered the most reliable prognostic parameters, but other biological factors are under study in order to improve patient stratification. Deoxyribonucleic acid (DNA) ploidy has been suggested to be useful in this setting. We retrospectively studied 79 patient with nephroblastoma (58 pretreated with chemotherapy and 21 not pretreated) by means of flow cytometry. DNA content and synthetic phase values were correlated with pathologic features and outcome. DNA modifications induced by chemotherapy were investigated. Sixty-nine tumors were diploid and 10 aneuploid. DNA content did not correlate with clinical course and was not modified by pretreatment. Aneuploid tumors were restricted to lower stages. Mean S-phase rate was lower and did not vary according to histology in pretreated tumors, while it was higher and increased with grade (p = 0.007) in previously untreated tumors. The fraction of cells in synthetic activity was related to outcome: Patients whose tumors displayed higher S-phase rates had a more favorable clinical course. Ploidy did not appear to be of prognostic significance. S-phase rate decreased after chemotherapy (p = 0.0002) and was related to survival. The worse outcome of pretreated patients might be attributed to a minor sensitivity to postoperative treatment: Preoperative chemotherapy would decrease the cell proliferation and might select resistant cellular clones of (possible) neoplastic residues.