COVID-19 infection elicits textbook immune response.

Imunita po prodelané infekci SARS-CoV-2 byla dlouhodobe zpochybnována. Z jiných typu respiracních onemocnení vsak víme, ze bunky, které se vytvorí pri první infekci, dlouhodobe prezívají a pri opakované infekci je díky nim imunitní reakce rychlejsí a úcinnejsí. Popisuje se zvýsení hladin protilátek, jejich lepsí avidita a vznik nových variant. Jiz existující pametové B a T lymfocyty jsou pouzity jako "prototyp", který se dále vylepsuje. U reinfikovaných osob tak logicky klesá riziko vázných prubehu onemocnení. V predkládaném clánku jsou uvedeny výsledky dlouhodobého merení hladiny IgG protilátek proti proteinum S a N a IgA protilátek proti proteinu S u 4 osob, které prodelaly opakované infekce SARS-CoV-2 spojené s nárustem hladin protilátek a s méne závazným prubehem, nez mela primoinfekce. Tyto zkusenosti potvrzují i závery z nasí predchozí dlouhodobé studie imunity u senioru z roku 2020, v níz byla také pozorována reaktivace imunity u rekonvalescentu po pravdepodobné nové expozici SARS-CoV-2, ale bez prodelaného onemocnení. Prezentované výsledky potvrzují jiz dríve publikovaná fakta, tedy ze prodelání nemoci neposkytuje dlouhodobou ochranu pred reinfekcí, zvláste novou variantou viru, ale pokud jiz k reinfekci dojde, bývá její prubeh méne závazný nez pri primoinfekci.

Antibodies from previous infection bring sufficient and long-term protection against COVID-19.

One of the basic manifestations of an adaptive anti-infective immunity is the production of specific antibodies. The presence of antibodies can be detected in serum and serves as one of the diagnostic tools used to confirm past infection. Very often it also serves as a confirmation that the body has acquired immunity to the disease. The appearance of COVID-19 has cast a shadow of doubt on these textbook examples of antibody behavior. Information that repeatedly questions antibody measurement and its significance has been circulating among professionals and the general public. The aim of our article is to summarize the current knowledge on the immunity acquired following SARS-CoV-2 infection and to present the results of antibody testing from four Czech laboratories which have been measuring these antibodies for over one year. Our data suggest that commonly available diagnostic methods reliably predict the results of a virus neutralization test, which is the gold standard of immunity detection. By acknowledging those with naturally acquired anti-infective immunity, in addition to vaccinated individuals, we will significantly increase the perceived level of collective immunity.

What is the immunity of high school students to coronavirus?

Children and young people are at the least risk of coronavirus infection and the consequences of COVID-19. However, COVID-19 has dramatically affected their lives due to many months of school closures intended to prevent the spread of the infection. In the Czech Republic, secondary schools were closed from 14 October 2020 to 24 May 2021 with a short break before Christmas. However, the students were most often infected by their parents, who usually became infected at work. The aim of this study was to find out by means of antibody testing how many high school students in Havlíčkův Brod have undergone the infection. We used questionnaires to find out how many students were in quarantine. The group included 196 students aged 15-19. Examination of IgG antibodies against the S antigen (Abbott, Architect) was performed in June 2021. Antibodies were detected in 90 of 196 students (45.9%). Coronavirus infection was reported in 88 families. Antibodies were detected in 61 quarantined students (69.3%), while the remaining 27 students had neither antibodies, nor clinical signs, nor positive PCR test. Thus, these students are considered unsusceptible to the infection at the time of quarantine. Despite the interruption of teaching in schools and the associated reduction of contacts, a significant share of students met with the coronavirus. About half of the students in the sample are already largely resistant to the disease (have antibodies). Another part of the students was unsusceptible to the disease, because they did not fall sick despite having been in contact with an infected family member.

COVID-19 antibody testing: examination of the antibody response to coronavirus in common practice.

Antibody identification is an important diagnostic tool that allows us to confirm a past SARS-CoV-2 infection. While antibody tests in the Czech Republic are yet to receive the attention they deserve, in the USA antibody testing has already become part of the diagnostic algorithms. The aim of this publication is to provide comprehensive information on the topic of antibody testing, the kinetics of antibody production, the types of tests and the issue of virus neutralization tests. Special attention is paid to the correct interpretation of test results and the issues surrounding reinfection.

Age is not a disease: Evolution of protective antibodies against SARS-CoV-2 in seniors from the Břevnice nursing home.

In the nursing home in Břevnice, 21 out of 23 seniors were infected with the SARS-CoV-2 virus in the spring of 2020. Three of them died from the infection. This study monitors the antibodies formation in group of seniors who have overcome the infection. Between April and November (1-8 months after the infection), the antibodies were measured repeatedly within the period of several weeks. The virus neutralizing tests was used as well as the ECLIA assay by Roche (total immunoglobulins), CMIA assay by Abbott (IgG) and ELISA assay by Euroimmun (IgG and IgA). Six months from the infection, neutralizing antibodies were detected in 18 out of 20 seniors. High levels of neutralizing antibodies correlated with higher levels of immunoglobulins and were a good predictor of an increase of IgG in the autumn during the second wave of the epidemic in the Czech Republic. During the autumn wave, neither any of the clients, nor any staff contracted the virus, although the prevalence of PCR positivity in the Vysočina region reached around 5 %. The antigen tests also came out all negative. This study shows that in the senior population, the production of protective antibodies follows a normal pattern, and the seniors are probably immune to a repeated infection for at least 8 months from the first infection. Based on these results, we would like to open the discussion on the testing for seroprevalence in nursing homes, possible changes to the epidemiologic regime in relation to the risk of infection, and about vaccination schemes in these centers.