Efficacy and effectiveness of influenza vaccination in healthy children. A review of current evidence.

Influenza is common in healthy children and adolescents and is associated with a high rate of hospitalization in this group, especially for those <5 years. Although the WHO has recommended vaccination in children under 5 years of age since 2012, it is really implemented in few countries today. The aim of this paper was to review the available evidence on the efficacy/effectiveness of influenza vaccination in healthy children <18 years of age through a non-systematic search of studies conducted between 2010 and 2020. Despite the high variability in results due to differences in design, vaccine type and season included in the 41 selected studies, statistically significant studies show efficacy values for the influenza vaccine of between 25.6% and 74.2%, and effectiveness from 26% to 78.8%. Although a systematic review would be necessary to corroborate the evidence, this review suggests that paediatric vaccination is generally an effective measure for preventing influenza in healthy children in line with international organisms' recommendations.

A tool for early estimation of influenza vaccination coverage in Spanish general population and healthcare workers in the 2018-19 season: the Gripómetro.

ASBTRACT: BACKGROUND: Electronic vaccine registries are not yet widely established. There is a need to real-time monitor influenza vaccine coverage, which may raise awareness to risk groups and professionals, and eventually allow to adopt tailored measures during the vaccination campaign. To evaluate the utility of the "Gripómetro", a demographic study designed to monitor national and regional influenza vaccine coverage on a weekly basis in Spain. METHODS: Quantitative study based on surveys of the Spanish population between 18-80 years and a sample of primary care doctors and nurses randomly selected. Pre-proportional fixation has been established by Autonomous Communities and age group to guarantee the representativeness of all the autonomies. RESULTS: Interviews were conducted in 3400 households of general population and 807 respondents among health care professionals. We found that the results of influenza vaccination coverage in the population ≥ 65 years obtained by the Gripómetro for 2018-2019 season were mostly comparable with the official data presented by the Ministry of Health after the end of the vaccination campaign. CONCLUSIONS: The Gripómetro is a robust research method that provides real-time data and trends for influenza vaccine coverage along with other useful information related to vaccination such as intention to vaccinate, motivation and barriers to vaccination.

Influenza B Lineages Have More in Common Than Meets the Eye. Trivalent Influenza Vaccines Trigger Heterotypic Antibodies Against Both Influenza B Viruses.

Influenza B is accountable for an important burden during flu epidemics, causing special impact in children and the elderly. Vaccination is the best approach to address influenza infections. However, one of the main problems of this virus is that two different lineages circulate together, Victoria and Yamagata; and trivalent vaccines, that only contain one of these lineages, are still in use. For that reason, if during an epidemic, the lineage not included in the vaccine predominates, a mismatch would occur, and the vaccine effectiveness will be very poor. In this work, we evaluated the cross-protection given by the trivalent Influenza vaccine and compared serological profiles based on age, sex, and the type of vaccine used. We performed a retrospective analysis of serum samples obtained before and after seasonal influenza vaccination during 20 seasons (1998-2018). The results showed that heterotypic reactivity between both influenza B lineages is common, but always lower than the homologous response. Age is a relevant factor for this cross-reactivity between both lineages, while the sex and the type of vaccine not. Vaccination with trivalent influenza vaccines elicits cross-reactive antibodies against both lineages, however, this response might not be enough to provide an appropriate serological protection in case of mismatch.

Estimation of Reduction in Influenza Vaccine Effectiveness Due to Egg-Adaptation Changes-Systematic Literature Review and Expert Consensus.

BACKGROUND: Influenza vaccines are the main tool to prevent morbidity and mortality of the disease; however, egg adaptations associated with the choice of the manufacturing process may reduce their effectiveness. This study aimed to estimate the impact of egg adaptations and antigenic drift on the effectiveness of trivalent (TIV) and quadrivalent (QIV) influenza vaccines. METHODS: Nine experts in influenza virology were recruited into a Delphi-style exercise. In the first round, the experts were asked to answer questions on the impact of antigenic drift and egg adaptations on vaccine match (VM) and influenza vaccine effectiveness (IVE). In the second round, the experts were presented with the data from a systematic literature review on the same subject and aggregated experts' responses to round one questions. The experts were asked to review and confirm or amend their responses before the final summary statistics were calculated. RESULTS: The experts estimated that, across Europe, the egg adaptations reduce, on average, VM to circulating viruses by 7-21% and reduce IVE by 4-16%. According to the experts, antigenic drift results in a similar impact on VM (8-24%) and IVE (5-20%). The highest reduction in IVE was estimated for the influenza virus A(H3N2) subtype for the under 65 age group. When asked about the frequency of the phenomena, the experts indicated that, on average, between the 2014 and 19 seasons, egg adaptation and antigenic drift were significant enough to impact IVE that occurred in two and three out of five seasons, respectively. They also agreed that this pattern is likely to reoccur in future seasons. CONCLUSIONS: Expert estimates suggest there is a potential for 9% on average (weighted average of "All strains" over three age groups adjusted by population size) and up to a 16% increase in IVE (against A(H3N2), the <65 age group) if egg adaptations that arise when employing the traditional egg-based manufacturing process are avoided.

Do Vaccines Need a Gender Perspective? Influenza Says Yes!

Background: Sex differences in immune responses are well known. However, the humoral response in males and females in the case of influenza vaccination is yet to be characterized since studies have shown uneven results. Methods: A retrospective study was conducted in 2,243 individuals (46.9% males) divided by age (15-64 and ≥65 years old). A serological analysis was performed by hemagglutination inhibition assay (HI) just before and 28 days after annual vaccination against seasonal influenza viruses in people vaccinated during the 2006-2018 seasons. A comparison of the humoral responses against influenza A and B viruses contained in the vaccine, between male and female individuals in young adults and elderly was conducted. Results: Significative higher humoral response against classical influenza A (H1N1), A(H1N1)pdm09 subtype and B/Victoria lineage in terms of seroconversion rate were found in elderly women. No significant differences were found in the case of A(H3N2) subtype. Conclusions: Elderly women seem to display a greater humoral response against classical A(H1N1), pandemic A(H1N1)pmd09 and B/Victoria lineage than elderly men. Sex dimorphism does not affect young adults.

[SEPAR Recommendations for COVID-19 Vaccination in Patients With Respiratory Diseases]. / Recomendaciones SEPAR sobre la vacuna COVID-19 en las enfermedades respiratorias.

The Spanish Society of Pneumonology and Thoracic Surgery (SEPAR) has elaborated this document of recommendations for COVID-19 vaccination in patients with respiratory diseases aimed to help healthcare personnel make decisions about how to act in case of COVID-19 vaccination in these patients.The recommendations have been developed by a group of experts in this field after reviewing the materials published up to March 7, 2021, the information provided by different scientific societies, drug agencies and the strategies of the governmental bodies up to this date.We can conclude that COVID-19 vaccines are not only safe and effective, but also prior in vulnerable patients with chronic respiratory diseases. In addition, an active involvement of healthcare professionals, who manage these diseases, in the vaccination strategy is the key to achieve good adherence and high vaccination coverage.

Adjuvanted Influenza Vaccines Elicits Higher Antibody Responses against the A(H3N2) Subtype than Non-Adjuvanted Vaccines.

BACKGROUND: vaccination is the best approach to prevent influenza infections so far. Serological studies on the effect of different vaccine types are important to address vaccination campaigns and protect our population. In our study, we compared the serological response against influenza A subtypes using the non-adjuvanted influenza vaccine (NAIV) in adults and the elderly and the adjuvanted influenza vaccine (AIV) in the elderly. METHODS: We performed a retrospective analysis by hemagglutination inhibition assay (HI) of serum samples right before and 28 days after seasonal influenza vaccination during the 1996-2017 seasons. CONCLUSIONS: The AIV presents better performance against the A(H3N2) subtype in the elderly whereas the NAIV induces a better response against A(H1N1)pdm09 in the same group.

Comparative study of the prevalence of the human papilloma virus in Spanish and foreign women participating in a population screening programme in Castilla y León. / Estudio comparativo de la prevalencia de virus de papiloma humano en las mujeres españolas y extranjeras, participantes en un programa de cribado poblacional en Castilla y León.

INTRODUCTION: The objective of this study was to compare the prevalence of human papilloma virus (HPV) in Spanish and foreign women in a cervical cancer screening programme of Castilla y León and foreign women living in the community who participated in the programme. METHODS: This was an observational, descriptive, cross - sectional, retrospective study of period prevalence. The sample consisted of all the women included in the cervical cancer prevention programme of the Regional Ministry of Health of the Junta de Castilla y León who were screened for cervical cancer during the period from 2012 to 2014, aged between 25 and 64 years of age. RESULTS: Of the 190,203 cervical smear samples collected, 10.2% were foreign (n=19,329). The prevalence of HPV in the foreign women was 23.51%, significantly higher than in the Spanish women (P<.001). The presence of morphological and microbiological changes in the foreign women was also greater. CONCLUSIONS: This study makes an important contribution, since it comprised a voluminous population screening sample. The prevalence of HPV in the foreign women was significantly higher than in the women born in Spain. It is important to continue studying this type of population, who are difficult to recruit for cultural reasons.

Diagnostic challenges in influenza. / Retos diagnósticos de la gripe.

In 2018 there are still microbiology laboratories that do not subtype or detect influenza viruses, one of the main agents of community-acquired pneumonia. A major challenge is to introduce multiplex-type technologies into most clinical virological diagnostic laboratories, increasing the feasibility of timely etiological diagnosis of influenza and other respiratory viruses whenever required and thus limiting antibiotic treatments. Other diagnostic tools such as markers of severity and the detection of resistance are pending challenges to complete and expand. Viral culture, an essential tool in the epidemiological surveillance of viruses, has been relegated by more sensitive and affordable molecular techniques. Sequencing of the influenza virus together with the antigenic characterisation and detection techniques of antibodies against hemagglutinin and neuraminidase will, in future, be used in tandem with other techniques to detect antibodies against other structural proteins, helping to elucidate the complicated epidemiology of these viruses and the production of new vaccines and their evaluation. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016¼, which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A. © 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved.

[In vitro activity of ceftaroline against Spanish isolates of Staphylococcus aureus: a multicenter study]. / Estudio multicéntrico sobre la actividad in vitro de ceftarolina frente a Staphylococcus aureus aislados en España.

INTRODUCTION: Ceftaroline fosamil is a new-generation antimicrobial agent of cephalosporins subgroup. It is the first commercially available beta-lactam antibiotic that exhibits activity against methicillin-resistant Staphylococcus aureus (MRSA). The aim of this study is to determine the in vitro Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values of ceftaroline against S.aureus strains (including MRSA). MATERIAL AND METHODS: A multicenter study involving four hospitals representative of the Spanish geography was performed. MIC and MBC values against both the methicillin-resistant and sensitive strains of S.aureus (MRSA and methicillin-sensitive S.aureus [MSSA]) were determined using a broth microdilution method. RESULTS: A total of 266 S.aureus strains were analyzed (95 MRSA and 171 MSSA). Ceftaroline bacterial sensitivity showed a mean MIC of 0.227 µg/ml (SD=0.146; range, 0.06 to 1 µg/ml). All MIC values of the 266 strains tested belonged to the sensitive category (value ≤ 1 µg/ml). Intermediate or resistant strains were not detected. MIC50 and MIC90 values for MRSA were 0.25 and 0.5 µg/ml, respectively (range=0.125-1 µg/ml). MSSA strains showed MIC50 and MIC90 values of 0.125 and 0.25 µg/ml, respectively (range=0.125-0.5 µg/ml). MBC50 and MBC90 values for MRSA were 0.5 and 1 µg/ml, respectively (range=0.125-1 µg/ml). MSSA strains showed MBC50 and MBC90 values of 0.25 and 0.25 µg/ml, respectively (range=0.125-0.5 µg/ml). CONCLUSION: Ceftaroline shows excellent in vitro activity against S.aureus, including MRSA strains. Therefore, this antibiotic may be a promising alternative for the treatment of infections caused by this bacterium.

New procedure for rapid identification of microorganisms causing urinary tract infection from urine samples by mass spectrometry (MALDI-TOF).

INTRODUCTION: Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry is widely established as a technique in clinical microbiology laboratories for the identification of microorganisms. Using this technique, it is also possible to obtain the identification of microorganisms from untreated urine samples. METHODS: In this study, a differential centrifugation protocol and a criterion for validation of the results in order to achieve microbial identification from untreated urine samples are proposed. Additionally, the sensitivity of the analytical procedure in monobacterial urine samples has been evaluated. RESULTS: A 90% sensitivity (confidence interval of 81.96%-94.84%) was obtained in urine samples with bacterial counts of ≥1×10(5)CFU/ml, and it was possible to improve the percentages of direct identifications from urine samples with bacterial counts of <1×10(5)CFU/ml. CONCLUSION: It is concluded that the MALDI-TOF system is both fast and reliable in the identification of individual microorganisms from untreated urine samples with counts of ≥1×10(5)CFU/ml.

[Profile of paediatric admissions and emergencies during an epidemic period of rotavirus in Valladolid [Spain]. Utility of a predictive model]. / Perfil de ingresos y urgencias pediátricas en período epidémico de rotavirus en Valladolid. Utilidad de un modelo predictivo.

INTRODUCTION: The aim of this study was to determine the weeks of high rotavirus circulation in Valladolid (Spain) and to compare the characteristics of hospitalizations and emergencies in epidemic and nonepidemic periods. METHODS: The information sources consisted of the weekly notifications to the Microbiological Information System, the Minimum Data Set, and the Emergency Registry. Expected cases for 2006 were calculated using a previously developed model. Weeks with observed cases over the upper limit of the 95% confidence interval for expected cases were considered epidemic periods. Hospitalization and emergencies in epidemic and nonepidemic periods were compared. RESULTS: The number of cases in 2006 was 42% less than the expected number. The mean number of daily admissions was higher in epidemic periods (d=1.49; p=0.01) and the length of admissions was longer. CONCLUSION: The activity of the paediatric service increased during the epidemic period. Consequently, implementation of surveillance activities and prevention and control programs for rotavirus in hospitals would seem advisable.

Gastroenteritis by rotavirus in Spanish children. Analysis of the disease burden.

Rotavirus is one of the most common causes of gastroenteritis worldwide. With the commercialisation of effective rotavirus vaccines in Europe in sight, it is necessary to provide studies which evaluate the disease burden. The aim of this study is two-fold, on one hand, to determine the burden of the rotavirus disease in Spanish children under the age of five, and on the other, to estimate the economic cost of these hospitalizations. The study was undertaken during a 5 year period (2000-2004). The rotavirus hospitalization rate was determined using the Minimum Basic Data Set of the national hospital discharge register. The observed data were compared with those expected by applying a model developed by the Centers for Disease Control and Prevention (CDC) adapted for European Countries. The financial expense of these hospitalizations was estimated. Of all admissions coded as gastroenteritis, 31.6% were due to rotavirus. The hospitalization rate by rotavirus was 480 cases per 100,000 children under five. These data are within the confidence range proposed by the adapted CDC model. The financial expense due to hospitalizations reaches 123,262 euros yearly in a Spanish University Hospital. In conclusion, rotavirus contributes significantly to the hospitalization of acute gastroenteritis. The rate of hospitalization by rotavirus is higher compared to other studies carried out in Spain. In view of future commercialisation of rotavirus vaccines, more in-depth analysis considering direct and indirect costs are necessary.

[Viral gastroenteritis. Application of a protocol for astrovirus detection in childhood gastroenteritis]. / Gastroenteritis de etiología vírica. Aplicación de un protocolo para el diagnóstico de astrovirus en casos de gastroenteritis infantil.

BACKGROUND AND OBJECTIVE: Diagnosis of viral gastroenteritis is an important subject in clinical virology which is mainly determined by the availability of reagents in laboratories, such as in the case of astrovirus. The aim of this study was to estimate the increase in the diagnostic performance achieved after the incorporation of astrovirus search in the diagnosis protocol of acute viral gastroenteritis. We also analyzed the trend of infections in other more commonly searched virus, such as rotavirus and enteric adenovirus. MATERIAL AND METHODS: Retrospective study during 20 years that included 12,980 stool samples processed for gastroenteritis virus diagnosis. Since 1997 an enzyme immunoassay for astrovirus has been applied to those samples that are negative for rotavirus and adenovirus. The study was divided in two periods (1986-1996 and 1997-2005, without and with astrovirus diagnosis) and the percentage of patients diagnosed in each period was compared. The trend of positive results as well as the percentage of positive results over all patients studied was modelled using the least squares method. RESULTS: The percentages of positive patients for rotavirus, adenovirus and astrovirus were 10.3%, 2.3% and 6.0% respectively, and there were uncommon co-infections by rotavirus and adenovirus (0.2%). The protocol applied to the astrovirus diagnosis increased the diagnosis rate up to 16.8% of the studied cases. Significant statistical differences were observed between the 2 study periods. A quadratic growth was observed in the results of positive diagnosis of viral gastroenteritis during the study period. CONCLUSIONS: The search of astrovirus in gastroenteritis cases by a selective protocol increased the diagnostic performance of gastrointestinal virus by 6%. In view of these results, it would be useful to implement astrovirus diagnosis in faeces with liquid or semi-liquid consistency when rotavirus and adenovirus detection is negative.