Seroprevalence of Protective Antibodies Against Influenza and the Reduction of the Influenza Incidence Rate: An Annual Repeated Cross-Sectional Study From 2014 to 2019.

BACKGROUND: Seroepidemiological studies provide estimates of population-level immunity, prevalence/incidence of infections, and evaluation of vaccination programs. We assessed the seroprevalence of protective antibodies against influenza and evaluated the correlation of seroprevalence with the cumulative annual influenza incidence rate. METHODS: We conducted an annual repeated cross-sectional seroepidemiological survey, during June-August, from 2014 to 2019, in Portugal. A total of 4326 sera from all age groups, sex, and regions was tested by hemagglutination inhibition assay. Seroprevalence and geometric mean titers (GMT) of protective antibodies against influenza were assessed by age group, sex, and vaccine status (65+ years old). The association between summer annual seroprevalence and the difference of influenza incidence rates between one season and the previous one was measured by Pearson correlation coefficient (r). RESULTS: Significant differences in seroprevalence of protective antibodies against influenza were observed in the population. Higher seroprevalence and GMT for A(H1N1)pdm09 and A(H3N2) were observed in children (5-14); influenza B seroprevalence in adults 65+ was 1.6-4.4 times than in children (0-4). Vaccinated participants (65+) showed significant higher seroprevalence/GMT for influenza. A strong negative and significant correlation was found between seroprevalence and ILI incidence rate for A(H1N1)pdm09 in children between 5 and 14 (r = -0.84; 95% CI, -0.98 to -0.07); a weak negative correlation was observed for A(H3N2) and B/Yamagata (r ≤ -0.1). CONCLUSIONS: The study provides new insight into the anti-influenza antibodies seroprevalence measured in summer on the ILI incidence rate in the next season and the need for adjusted preventive health care measures to prevent influenza infection and transmission.

Stevens-Johnson syndrome related with Comirnaty® coronavirus disease 2019 vaccine.

Stevens-Johnson syndrome is a rare severe delayed-type hypersensitivity reaction. Even though not initially described as a side-effect of the Comirnaty® coronavirus disease 2019 (COVID-19) Vaccine, the worldwide public COVID-19 vaccination programs are uncovering this serious adverse event. We present the case of a 44-year-old woman, vaccinated with the 1st dose in July 2021, and the 2nd dose 4 weeks later. Five days after the 2nd dose, a 10 cm, circular, painful, violet/red lesion appeared on the injection site. From then on, multiple, generalized purpuric painful lesions appeared, associated with ulcers on the lips, oral cavity, nasal cavity, vulva, and vagina, oedema of the hands and feet, conjunctival erythema, blurred vision, and malaise. The patient was being treated with lamotrigine and sodium valproate (for 2 years, without interruptions or dose change) which were stopped, and the patient started treatment with systemic corticosteroids. Lymphocyte transformation test were performed and were positive for PEG2000 1 µg/mL (stimulation index [SI], 30.9), and the undiluted Comirnaty® vaccine (SI, 32.2). These tests were negative on several vaccinated controls. We can definitively show that sensitization to the vaccine and PEG2000 can occur. A more extensive evaluation and reporting is needed to know the true incidence of this life-threatening condition and possible risk factors; as not only further booster shots of this vaccine will be administered, but also new vaccines with the mRNA technology are likely to be more prevalent in the future.

Late-Onset Rash from Irbesartan: An Immunological Reaction.

Cutaneous delayed reactions to antihypertensive drugs have been described in a limited number of case reports but the mechanisms remain mostly unknown. We report the case of a 60-year-old female patient with a 3-week history of an itchy erythematous maculopapular eruption. Although the patient was polymedicated, irbesartan was the most likely culprit. Patch tests and a lymphocyte transformation test to irbesartan were both positive, which was useful for diagnosis and suggested an immunological reaction. No new lesions appeared after irbesartan was stopped or after the introduction of candesartan. Despite its similar chemical structure, candesartan may be tried in patients allergic to irbesartan. LEARNING POINTS: Irbesartan can induce immunological cell-mediated skin reactions.Allergy to irbesartan does not imply a class allergy.Patch tests and a lymphocyte transformation test were useful in the diagnosis of irbesartan allergy.

Epidemiology and genetic variability of respiratory syncytial virus in Portugal, 2014-2018.

INTRODUCTION: Respiratory syncytial virus (RSV) is associated with substantial morbidity and mortality since it is a predominant viral agent causing respiratory tract infections in infants, young children and the elderly. Considering the availability of the RSV vaccines in the coming years, molecular understanding in RSV is necessary. OBJECTIVE: The objective of the present study was to describe RSV epidemiology and genotype variability in Portugal during the 2014/15-2017/18 period. MATERIAL AND METHODS: Epidemiological data and RSV-positive samples from patients with a respiratory infection were collected through the non-sentinel and sentinel influenza surveillance system (ISS). RSV detection, subtyping in A and B, and sequencing of the second hypervariable region (HVR2) of G gene were performed by molecular methods. Phylogenetic trees were generated using the Neighbor-Joining method and p-distance model on MEGA 7.0. RESULTS: RSV prevalence varied between the sentinel (2.5%, 97/3891) and the non-sentinel ISS (20.7%, 3138/16779), being higher (P < 0.0001) among children aged <5 years. Bronchiolitis (62.9%, 183/291) and influenza-like illness (24.6%, 14/57) were associated (P < 0.0001) with RSV laboratory confirmation among children aged <6 months and adults ≥65 years, respectively. The HVR2 was sequenced for 562 samples. RSV-A (46.4%, 261/562) and RSV-B (53.6%, 301/562) strains clustered mainly to ON1 (89.2%, 233/261) and BA9 (92%, 277/301) genotypes, respectively, although NA1 and BA10 were also present until 2015/2016. CONCLUSION: The sequence and phylogenetic analysis reflected the relatively high diversity of Portuguese RSV strains. BA9 and ON1 genotypes, which have been circulating in Portugal since 2010/2011 and 2011/2012 respectively, predominated during the whole study period.

Cross-protection to new drifted influenza A(H3) viruses and prevalence of protective antibodies to seasonal influenza, during 2014 in Portugal.

INTRODUCTION: Immune profile for influenza viruses is highly changeable over time. Serological studies can assess the prevalence of influenza, estimate the risk of infection, highlight asymptomatic infection rate and can also provide data on vaccine coverage. The aims of the study were to evaluate pre-existing cross-protection against influenza A(H3) drift viruses and to assess influenza immunity in the Portuguese population. MATERIALS AND METHODS: We developed a cross-sectional study based on a convenience sample of 626 sera collected during June 2014, covering all age groups, both gender and all administrative health regions of Portugal. Sera antibody titers for seasonal and new A(H3) drift influenza virus were evaluated by hemagglutination inhibition assay (HI). Seroprevalence to each seasonal influenza vaccine strain virus and to the new A(H3) drift circulating strain was estimated by age group, gender and region and compared with seasonal influenza-like illness (ILI) incidence rates before and after the study period. RESULTS: Our findings suggest that seroprevalences of influenza A(H3) (39.9%; 95% CI: 36.2-43.8) and A(H1)pdm09 (29.7%; 95% CI: 26.3-33.4) antibodies were higher than for influenza B, in line with high ILI incidence rates for A(H3) followed by A(H1)pdm09, during 2013/2014 season. Low pre-existing cross-protection against new A(H3) drift viruses were observed in A(H3) seropositive individuals (46%). Both against influenza A(H1)pdm09 and A(H3) seroprotection was highest in younger than 14-years old. Protective antibodies against influenza B were highest in those older than 65years old, especially for B/Yamagata lineage, 33.3% (95% CI: 25.7-41.9). Women showed a high seroprevalence to influenza, although without statistical significance, when compared to men. A significant decreasing trend in seroprotection from north to south regions of Portugal mainland was observed. CONCLUSIONS: Our results emphasize that low seroprotection increases the risk of influenza infection in the following winter season. Seroepidemiological studies can inform policy makers on the need for vaccination and additional preventive measures.