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The present study assesses the seroprevalence of antibodies against seasonal human alphacoronaviruses 229E and NL63 among adult patients infected with SARS-CoV-2, and its association with the humoral response to SARS-CoV-2 infection and its severity, and influenza vaccination. A serosurvey was conducted to quantify the presence of IgG antibodies against the nucleocapsid of 229E (anti-229E-N) and NL63 (anti-NL63-N), and anti-SARS-CoV-2 IgG antibodies (against nucleocapsid, receptor-binding domain, S2 domain, envelope, and papain-like protease) for 1313 Polish patients. The seroprevalence of anti-229E-N and anti-NL63 in the studied cohort was 3.3% and 2.4%. Seropositive individuals had a higher prevalence of anti-SARS-CoV-2 IgG antibodies, higher titers of the selected anti-SARS-CoV2 antibodies, and higher odds of an asymptomatic SARS-CoV-2 infection (OR = 2.5 for 229E and OR = 2.7 for NL63). Lastly, the individuals vaccinated against influenza in the 2019/2020 epidemic season had lower odds of seropositivity to 229E (OR = 0.38). The 229E and NL63 seroprevalence was below the expected pre-pandemic levels (up to 10%), likely due to social distancing, increased hygiene, and face masking. The study also suggests that exposure to seasonal alphacoronaviruses may improve humoral responses to SARS-CoV-2 while decreasing the clinical significance of its infection. It also adds to accumulating evidence of the favorable indirect effects of influenza vaccination. However, the findings of the present study are of a correlative nature and thereby do not necessarily imply causation.

How frequently autoantibodies against angiotensin-converting enzyme 2 (ACE2) occur in patients infected by SARS-CoV-2 is understudied and limited to investigations on a small sample size. The presence of these antibodies may contribute to the long-lasting effects of COVID-19 observed in some individuals, particularly if IgG-class antibodies would emerge in patients. This study assessed the prevalence of IgG autoantibodies against ACE2 in 1139 patients infected with SARS-CoV-2 and examined their relationship with severity, demographic characteristics, and status of vaccination against influenza. The overall prevalence of anti-ACE IgG antibodies in our cohort was 1.5%. Most of these individuals were men (76.5%) and underwent mild COVID-19, but some severe and asymptomatic cases were also observed. Patients with severe infection had twofold higher titers than mild and asymptomatic cases. Age, comorbidities, and influenza vaccination status were not related to antibody prevalence. The prevalence of IgG anti-SARS-CoV-2 antibodies (against nucleocapsid protein and S2 subunit, but not against receptor-binding domain) was higher in the subset with ACE2 autoantibodies. Further research is required to understand the potential spectrum and duration of effects of IgG autoantibodies against ACE2 in patients after SARS-CoV-2 infection, particularly concerning long COVID-19.

The aim of the study was to prove the level of antibodies against haemagglutinin in the sera of people from seven age groups in the epidemic season 2020/2021 in Poland to determine the differentiation of the antibody level and the protection rate depending on age. The level of anti-haemagglutinin antibodies was established by haemagglutinin inhibition test (HAI). A total of 700 randomly selected sera from people belonging to 7 different age groups were tested. The results confirmed the presence of antibodies against the following influenza antigens: A/Guangdong-Maonan/SWL1536/2019 (H1N1)pdm09-like virus, A/Hong Kong/2671/2019 (H3N2)-like virus, B/Washington/02/2019 (B/Victoria lineage)-like virus and B/Phuket/3073/2013 (B/Yamagata lineage)-like virus. The level of haemagglutinin antibodies varied between the studied age groups, with the highest values in the 5–9 age group and the lowest in the 0–4 age group. It was also proven that the protection rate was the highest for the A/Hong Kong/2671/2019(H3N2)-like virus antigen, which exceeded the protection level in the 5 age groups. Considering the very low percentage of people vaccinated in the epidemic season 2020/2021 in Poland, which amounted to only 6.1%, the results should be interpreted as the immune system’s response to an infection with influenza virus.

Members of the European Influenza Surveillance Network: Portugal (Figueiredo Augusto Gonçalo, Machado Jorge, Moreira Guiomar Raquel, Nogueira Paulo, Rebelo de Andrade Helena, Rodrigues Ana Paula) The yearly influenza epidemics during each winter season vary in burden and severity. During the 2016/17 and 2017/18 seasons, all-cause excess mortality was observed during periods of high influenza virus circulation. Our aim is to describe and compare the pattern of influenza virus circulation and related disease severity by number of patients and fatal cases in intensive care units (ICUs) across European Union/European Economic Area (EU/EEA) countries for the seasons 2016/17 and 2017/18. As influenza circulation progressed from a west to east direction across Europe in 2017/18, a better understanding of the current epidemiological situation might help to prepare countries in the eastern part of the World Health Organization (WHO) European Region for high influenza activity and severity. info:eu-repo/semantics/publishedVersion

Being frequent travelers, the elite athletes are advised to undergo an influenza vaccination. The aim of the study was to describe the antibody response to repeated trivalent, inactivated, split influenza vaccine, of different antigenic content, recommended for the Northern and the Southern Hemisphere, administered to sportsmen before the Olympic Games in Brasil in 2016. Fourteen athletes were included in the study. For both A/California/7/209/pdm09 A/H1N1/ antigen and A/Switzerland/971593/2013/A/H3N2/ antigen, higher seroconversion rates were obtained after the first than the second vaccination (10.2 vs. 1.5 and 10.6 vs. 3.0, respectively; p 0.05 both). Conversion rates for B/Phuket/3073/2013, B/Brisbane/60/2008, and A/HongKong/4801/2014/A/H3N2/ antigens were lower. Nonetheless, the protection rate was greater than 70% for all antigens contained in both vaccines. The proportion of individuals demonstrating a high level of both protection rate and response rate was greater after the first than the second vaccination. We conclude that the immunological response after influenza vaccination is good in elite athletes and remains so after a second influenza vaccination required due to a different vaccine composition recommended for different hemispheres.

Respiratory syncytial virus (RSV) is considered the major pathogen causing severe lower respiratory tract infections among infants and young children [1]. RSV is the most common cause of hospitalisation for acute lower respiratory tract infection in children younger than 5 years and is estimated to cause between 66,000 and 199,000 deaths worldwide every year [2]. Its significance in causing substantial morbidity and hospitalisation in the first year of life has been affirmed in a recent study and a meta-analysis [3,4]. In England, average annual hospital admission rates are 35.1 per 1,000 children younger than 1 year and 5.31 per 1,000 children aged 1–4 years [5]. In addition to children, RSV causes a substantial disease burden in elderly people and patients with chronic obstructive pulmonary disease [6,7]. RSV causes seasonal epidemics worldwide [8], with one to two epidemics each year [9] following latitudinal gradients in timing, duration, seasonal amplitude and between-year variability [8,9]. In some studies, the seasonal periodicity has been connected to climatic factors [9-11], but a common factor that explains all observed periodicity has not been established. Meteorological conditions such as temperature and high relative humidity have been reported as important predictors of RSV epidemics [9,12]. In the United States (US) and Japan, annual national and regional variation of RSV season onset and end has been reported [13-15]. In the Nordic countries, a major outbreak often alternates with a minor one, with the minor peak in the spring and a major one the following winter [16-19], a phenomenon reported also in Croatia [20], Denmark [21] and Germany [22]. RSV antigenic groups A and B alternate in two-year cycles in Finland, with dominance of the group A viruses in years 1981–82, 1985–86 and 1989–90 and the group B viruses 1983–84 and 1987–88 [17,19], and different genotypes dominate the circulation in consecutive epidemics in Korea [23]. In Spain, no biennial rhythm has been detected but rather a stable annual epidemic with a peak between week 52 and week 1 and circulation 2–8 weeks earlier than influenza viruses [24]. Similarly, in the United Kingdom (UK), one stable epidemic per year is observed [5]. Immunoprophylaxis to prevent RSV infection with a neutralising monoclonal antibody, palivizumab, has been developed for administration to target groups on a monthly basis during the RSV season [25]. However, this drug is limited to high-risk infants, the cost prohibits its use in low- and middle-income countries and the data on effectiveness of the drug in children at high risk other than infants born at gestational age

Influenza virus neuraminidase inhibitors (NAIs), including oseltamivir, zanamivir and peramivir, are important antivirals for the treatment and prophylaxis of influenza. Increasing use of NAIs brings into focus the risk of drug resistance. The problem of resistance is of high clinical and epidemiological importance. There are generally three levels of antiviral resistance according to the way that resistance can be detected or inferred: genotypic, phenotypic and clinical resistance. Recently the problem of resistance to NAIs, although still rare (

I-MOVE/I-MOVE+ study team: Portugal - Baltazar Nunes, Ausenda Machado, Ana Paula Rodrigues, Verónica Gomez, Irina Kislaya, Mafalda Sousa Uva (Departamento de Epidemiologia, Instituto Nacional de Saúde Doutor Ricardo Jorge); Raquel Guiomar, Pedro Pechirra, Paula Cristóvão, Patrícia Conde, Inês Costa (Departamento de Doenças Infeciosas, Instituto Nacional de Saúde Doutor Ricardo Jorge). I-MOVE/I-MOVE+study team - Portugal: Baltazar Nunes, Departamento de Epidemiologia, Instituto Nacional de Saúde Dr. Ricardo Jorge; Ausenda Machado, Departamento de Epidemiologia, Instituto Nacional de Saúde Dr. Ricardo Jorge; Ana Paula Rodrigues, Departamento de Epidemiologia, Instituto Nacional de Saúde Dr. Ricardo Jorge; Verónica Gomez, Departamento de Epidemiologia, Instituto Nacional de Saúde Dr. Ricardo Jorge; Irina Kislaya, Departamento de Epidemiologia, Instituto Nacional de Saúde Dr. Ricardo Jorge; Mafalda Sousa Uva, Departamento de Epidemiologia, Instituto Nacional de Saúde Dr. Ricardo Jorge; Raquel Guiomar, Departamento de Doenças Infeciosas, Instituto Nacional de Saúde Dr. Ricardo Jorge; Pedro Pechirra, Departamento de Doenças Infeciosas, Instituto Nacional de Saúde Dr. Ricardo Jorge; Paula Cristóvão, Departamento de Doenças Infeciosas, Instituto Nacional de Saúde Dr. Ricardo Jorge; Patrícia Conde, Departamento de Doenças Infeciosas, Instituto Nacional de Saúde Dr. Ricardo; Jorge Inês Costa, Departamento de Doenças Infeciosas, Instituto Nacional de Saúde Dr. Ricardo Jorge. We measured early 2016/17 season influenza vaccine effectiveness (IVE) against influenza A(H3N2) in Europe using multicentre case control studies at primary care and hospital levels. IVE at primary care level was 44.1%, 46.9% and 23.4% among 0-14, 15-64 and ≥ 65 year-olds, and 25.7% in the influenza vaccination target group. At hospital level, IVE was 2.5%, 7.9% and 2.4% among ≥ 65, 65-79 and ≥ 80 year-olds. As in previous seasons, we observed suboptimal IVE against influenza A(H3N2). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 634446. info:eu-repo/semantics/publishedVersion

We present early estimates (up to week 4 of 2011) of the 2010/11 seasonal influenza vaccine effectiveness in preventing medically attended influenza-like illness(ILI) laboratory confirmed as influenza. Practitioners from seven European sentinel networks systematically swabbed ILI patients. We included patients meeting the European Union ILI case definition and swabbed less than eight days after symptom onset. Laboratory-confirmed influenza cases were compared with negative controls. The adjusted vaccine effectiveness was 42.3% (95% CI: -7.3 to 69.0%), suggesting moderate protection of the seasonal vaccine. The I-MOVE network has been funded by the European Centre for Disease Prevention and Control (ECDC) since 2007. Sí

Since 1997, human infections with highly pathogenic zoonotic avian influenza viruses have shown that the risk of influenza pandemic is significant. In Europe, infections caused by the highly pathogenic avian influenza A(H7N7) virus were confirmed in the human population in 2003 in the Netherlands. Moreover, outbreaks of A(H5N1) infections were observed in wild and farm birds in different European regions, including Poland in 2006-2008. This study presents 16 patients in Poland from whom clinical specimens were collected and tested for A(H5N1) highly pathogenic avian influenza. This article shows the results of laboratory tests and discusses the legitimacy of the collection and testing of the specimens. All patients were negative for A(H5N1) infection. Nevertheless, only two patients met clinical and epidemiological criteria from the avian influenza case definition. The conclusion is that there is still a strong necessity for increasing the awareness of medical and laboratory staff, as well as the awareness of some occupational groups about human infections with avian influenza viruses, including the importance of seasonal influenza vaccination. It should also be emphasized that in the case of patients suspected of being infected with avian influenza, the information about clinical symptoms is insufficient and must be accompanied by a wide epidemiological investigation.

Since the first importation of influenza A(H1N1)v virus to Europe in late April of this year, surveillance data have been collected in the Member States of the European Union and European Free Trade Association. This is the first preliminary analysis of aggregated and individual data available as of 8 June 2009 at European level.

Influenza surveillance and increase of the percentage of population vaccinated against influenza have priority significance to combat influenza. In Poland 8.3% of the population have been vaccinated against influenza during the last epidemic season. Consequences of influenza infections are medical as well as economic. In the USA economic costs of influenza range, depending on the epidemic season, from 76 billions to 167 billions US dollars. WHO, prestigious Scientific Societies and European Union appeal to increase influenza vaccination coverage. These vaccinations are the most effective and the cheapest way to fight against influenza. During 6 years avian influenza virus, breaking species barrier, caused death of over 100 persons. Despite culling of millions of poultry, influenza virus A/H5N1/ caused infections in birds in many countries. There is unanimous conviction that the next influenza pandemic is an inevitable event. At present, it is not possible to answer two questions: when it will happen and what subtype will cause pandemic. All countries were obliged to prepare emergency plans for the next influenza pandemic.

In the case of influenza disease there is no possible to make unquestionable diagnosis only on the basis of clinical picture. Therefore, virological laboratory diagnostics is important, especially in hospitalized patients and those who highly risk post-influenza complications and severe course of the disease. Virological diagnostic tests for influenza and positive result obtained in these tests allow to use effective antiviral-antiinfluenza drugs as new generation drugs: oseltamivir and zanarnivir and also old generation drugs: amantadine and rimantadine. Since these antivirals are effective only in the case of influenza infection, diagnostic tests should be performed previously. Present methods allow to obtain the result of the test within less than l hour to 8 h. This is of great importance, because the administration of the drug within 36 h from the onset of symptoms is one of the factors condition­ing the effectiveness of antiviral therapy. In the present paper there are described four cases of hospitalized patients in whom the infection with influenza virus was confirmed by immunofluorescence test and RT-PCR, and then the antiviral-antiinfluenza drugs were immediately introduced. This antiviral therapy in a short time resulted in the improvement of patients' condition and allowed to discharge them from the hospital. Antiviral-antiinfluenza drugs together with virological diagnostics are the effective tool in the case of patients not vaccinated against influenza, who were infected with influenza virus and fell ill.

The WHO Global Agenda on Influenza calls for measuring the progress of national influenza vaccination programs. In response, the Macro-epidemiology of Influenza Vaccination (MIV) Study Group has gathered information on influenza vaccination in 56 countries. During the period 1997--2003, influenza vaccine distribution increased considerably in almost all countries. In 2003, the countries with the highest levels of vaccination (doses distributed/1000 population) were Canada (344), the Republic of Korea (311), the United States (286) and Japan (230). Most countries recommended influenza vaccination for elderly persons and those with high-risk medical conditions, including immuno-compromise. Fewer countries provided public reimbursement for vaccination through national or social health insurance. Higher levels of vaccination were not closely related to higher levels of economic development, but in many instances public reimbursement for vaccination seemed to be associated with greater vaccine use. From 1994 to 2003, the global use of influenza vaccines increased more than two-fold. In 2003, the 56 MIV Study Group countries accounted for approximately 95% of the 292 million doses of influenza vaccine distributed worldwide, and 62% of these doses were distributed within nine vaccine-producing countries in North America, Western Europe, Japan and Australia. However, influenza vaccination was increasing rapidly in many non vaccine-producing countries, and this change has important implications for pandemic vaccination.

Due to a high ability to change, the influenza virus is still a danger for humans. The outbreak of the next influenza pandemic is very probable. The disturbing events that occurred in Hong Kong in 1997 and in the beginning of 2003 confirmed such a possibility. Every year in Poland influenza causes from several hundred thousands to several millions of cases of infections. All over the world the annual number of influenza cases amounts to approximately 100 millions and from 0.5 million to 1 million patients die due to influenza. The most severe threat is connected with post-influenza complications that are the cause of death after influenza infection. The only one effective method of prophylaxis against influenza and its complications is vaccination. Moreover, since 1999 new anti-influenza drugs are available: oseltamivir (Tamiflu) and zanamivir (Relenza). They are effective for treatment or for treatment and prophylaxis of infections caused by influenza virus type A and also type B. The efficacy of these drugs depends on appropriate diagnosis. Due to this fact laboratory diagnostics of respiratory infections is so important and crucial. It should be emphasised that clinical symptoms of infection may indicate influenza even if the disease is caused by other viral or bacterial pathogen.

Every year approximately 100,000 millions of cases of influenza are registered all over the world. In the United States of America from 20,000 to 40,000 people die due to influenza and its complications every year. Vaccination is the best way of protection against this disease and its serious complications. The clinical efficacy and economic benefits of influenza vaccination is well proved and substantiated. Each year the Advisory Committee on Immunization Practices (ACIP), WHO, Atlanta, USA publishes recommendations for influenza vaccinations indicating which groups of people and patients should be vaccinated for clinical reasons and which of them--for epidemiological reasons. Depending on the country, vaccination policies for influenza vaccinations are different. In Poland vaccination against influenza is recommended for all groups mentioned in ACIP document. Nevertheless, there is no reimbursement system for influenza vaccinations in our country, even only for high-risk groups. Desite this, from year to year more and more people are getting immunized. National campaign carried out by the National Influenza Center, Warsaw resulted in over 200-fold increase of number of doses of influenza vaccines distributed in the epidemic season 2001/2002 when compared with the season 1992/93. This fact shows the importance and efficacy of educational activities together with scientific studies for positive changes in patients' and physicians' attitude to influenza vaccinations.

A total of 2,344,773 cases of influenza were reported in Poland in 1999, corresponding to 6066.1 cases per 100,000 population and was 2.8 times higher as compared with 1998. The highest influenza incidence rate (10,770.9 per 100,000) was reported in Małopolskie voivodeship. Children up to 14 years old accounted for 34.9% (818,629; incidence 10,616.2 per 100,000) of all reported influenza cases. A total of 3,925 persons required hospitalization, eight times more as compared with 1998. The number of deaths due to influenza amounted to 402. Compared with 1998, in 1999 reported influenza deaths increased 6.4 times. During the second two weeks of January 1999 four influenza strains of type B were isolated from patients aged 13, 16, 31, and 38. During the first part of February 1999 another two strains of influenza virus type B were obtained from persons aged 35 and 45. All six isolates were related antigenically to the vaccine strain B/Beijing/184/93 and were confirmed by the WHO Collaborating Center for Influenza Reference and Research, London.

In November and December 1993, 49 children, ages 4 to 20, suffering from acute lymphoblastic leukemia, were vaccinated against influenza in the Department of Paediatric Haematology and Oncology, Medical Academy in Warsaw. These patients were vaccinated either in the course of maintenance treatment or after treatment. Each dose of Wyeth USA subunit trivalent influenza vaccine contained 15 micrograms of hemagglutinin of strains recommended for that season. The level of antibody production was determined in pre- and post vaccination sera in the group of children with leukemia and the control group. It was determined that in the investigated group, the GMT increased more than four times for hemagglutinins H1N1 and H3N2. A somewhat lower increase was observed in case of hemagglutinin HB. The proportion of subjects protected after vaccination was 35% for hemagglutinin H1N1, 76% for H3N2 and 100% for HB. The response rate was 33% for hemagglutinin H1N1, 47% for H3N2 and 45% for HB. In the control group the proportion of subjects protected and the response rate were very low. The results show the significant immunological efficacy of the vaccine used in the vaccination against influenza in high risk groups.

The level of IgG antibodies before and post influenza vaccination for 6 strains of influenza A virus (4 representative for pandemics and 2 vaccine strains) was tested by dot blot method. Examinations was performed with 4 age groups (20 persons each), selected on the base of strain which probably caused primary infection in given group. No differences in answer to particular influenza A virus strains consistent with "original antigenic sin" were observed. High sensitivity of dot blot method was confirmed.

51 haemophilic children aged from 7 to 16 years was vaccinated against influenza in Paediatric Department of Haematology and Oncology in November and December of 1993. Each dose of subunit vaccine manufactured by Wyeth-USA, contained 15 micrograms of each haemagglutinin strains as recommended for the season. The antibody level was studied before and after influenza vaccination in vaccinated and control group as well. 5-time rise of geometric mean antibody titre was found for H1N1 and H3N2 antigens after vaccination of the children group. Slightly lower, 2.7-time rise of GMT was showed for HB haemagglutinin of influenza virus. There was no significant rise of GMT for any among three studied virus haemagglutinin.

Cold adapted variants of influenza viruses replicated at 30 degrees C and 37 degrees C were tested for isoelectric points (pl's) before and after passages in susceptible animals to check the stability of this marker. No differences were found in pI's for 3 strains--A/Pol/L/71, A/Phil/2/82 and A/Pol/79/85 which are really cold adapted viruses. On the other hand some differences in pI's for other strains were observed.

Resistance against proteolysis enzymes, detergents and chemical group-specific reagents has been compared for the neuraminidase and hemagglutinin of influenza virus replicated at low temperature and original strain replicated at 37 degrees C before and after passage in the susceptible animal organism - cotton rat. Our study indicated great differences between strains and temperature conditions to resistance of the neuraminidase and hemaglutinin to proteolytic enzymes, detergens and chemical group specific reagents. No differences was found for sensitivity of influenza virus replicated at low temperature before and after passages for 3 strains -A/Pol/L/71, A/Phil/2/82, A/Pol/79/85 which are really cold adapted viruses. On the other hand neuraminidase of this strains was more resistance to these treatments.

Swiss white mice were given intranasally suspension of influenza A virus (H3N2) isolated at different period of time and replicated in lowered temperatures in 11 days old chicken embryos. The presence of antigen in lung of animals was detected by IF. They were given the virus replicated at 30 degrees C at different rate depending on strain tested. No distinct differences were observed in haemagglutination inhibition antibody level. On the other hand the level of neuraminidase activity inhibiting antibodies level was significantly higher after giving virus replicated at 30 degrees C than after giving the virus replicated at 37 degrees C. In the case of epidemic strains 4-5 fold fold increase of immunogenicity of neuraminidase component was observed and in the remaining strains immunogenicity of neuraminidase increased 1-5-fold only.

Influenza A/H3N2/ virus strains derived from various isolations and replicated in lowered temperatures (37 degrees, 35 degrees, 33 degrees, 30 degrees) in chicken embryos were used for the study. An alteration of temperature optimum of neuraminidase activity was established after 12-15 passages of influenza virus in lowered replication temperature and it differed depending on tested strain. During adaptation process of viruses to lowered replication temperatures no correlation between neuraminidase activity and haemagglutinating titer was seen.

Peptide maps were prepared by high-voltage electrophoresis and chromatography for t 30 degrees C mutant and the original strain A Port Chalmers 1/73 H3N2 of influenza virus. Clear differences in the distribution and number of spots between the mutant and the original strain were found. The differences are due presumably to changes in the amino-acid sequences.

Cold adapted variants of influenza virus, replicated at 37, 35, 33 and 30 degrees C, were tested for capability to multiply in ferrets and to induce H and N antibodies. Virus grown at 30 degrees C differed from the other in electrophoretic mobility of its polypeptides in PAGE, in inducing higher level of N antibodies, and in higher intensity of immunofluorescence reaction in the respiratory tract.

A method for isolation of neuraminidase using pronase has been developed. Purified preparations have been recovered from two influenza B virus strains, B/Mass/3/66 and B/USSR/14/80. Physico-chemical properties of neuraminidases were compared; optimal conditions for the determination of neuraminidase activity of these strains were determined. Strains differences in thermostability, optimal pH, specificity to substrates were established. Neuraminidases, isolated or present in virions, were shown to be identical in enzymatic characteristics but to differ in thermostability.

The t 30 degrees C mutant of A Port Chalmers 1/73 (H3N2) influenza virus passaged in cotton rats was reisolated. The original mutant and the reisolated virus were compared, the following parameters being tested: NA activity, HA titer, sensitivity of NA and HA to proteolytic enzymes, detergents and temperature, and Michaelis constant of NA. No differences were found in the parameters tested, thus suggesting that features of the mutant remained stable after passage in the susceptible animal organism.