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1.
Clin Infect Dis ; 73(11): 2065-2072, 2021 12 06.
Article in English | MEDLINE | ID: covidwho-1560424

ABSTRACT

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has led to the development of various vaccines. Real-life data on immune responses elicited in the most vulnerable group of vaccinees older than age 80 years old are still underrepresented despite the prioritization of the elderly in vaccination campaigns. METHODS: We conducted a cohort study with 2 age groups, young vaccinees below the age of 60 years and elderly vaccinees over the age of 80 years, to compare their antibody responses to the first and second dose of the BNT162b2 coronavirus disease 2019 vaccination. RESULTS: Although the majority of participants in both groups produced specific immunoglobulin G antibody titers against SARS-CoV-2 spike protein, titers were significantly lower in elderly participants. Although the increment of antibody levels after the second immunization was higher in elderly participants, the absolute mean titer of this group remained lower than the <60 years of age group. After the second vaccination, 31.3% of the elderly had no detectable neutralizing antibodies in contrast to the younger group, in which only 2.2% had no detectable neutralizing antibodies. CONCLUSIONS: Our data showed differences between the antibody responses raised after the first and second BNT162b2 vaccination, in particular lower frequencies of neutralizing antibodies in the elderly group. This suggests that this population needs to be closely monitored and may require earlier revaccination and/or an increased vaccine dose to ensure stronger long-lasting immunity and protection against infection.


Subject(s)
COVID-19 , Age Factors , Aged , Aged, 80 and over , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/prevention & control , Cohort Studies , Female , Humans , Immunity , Immunoglobulin G/blood , Male , Middle Aged , Spike Glycoprotein, Coronavirus/immunology , Vaccination
2.
Front Med (Lausanne) ; 8: 746644, 2021.
Article in English | MEDLINE | ID: covidwho-1497092

ABSTRACT

Prophylactic vaccination against SARS-CoV-2 is one of the most important measures to contain the COVID-19 pandemic. Recently, break-through infections following vaccination against this virus have been reported. Here, we describe the humoral immune response of break-through infections in fully vaccinated individuals of old age from an outbreak in a nursing home. In cooperation with the local health authority, blood samples from fully vaccinated and infected as well as fully vaccinated and uninfected residents of the nursing home were collected 4 weeks after the onset of the outbreak. The humoral immune response was determined in a neutralisation assay with replication-competent virus isolates and by a quantitative ELISA. In this outbreak a total of 23 residents and four health care workers were tested positive for SARS-CoV-2. Four residents were unvaccinated, including one with a severe course of disease who later severe disease course who later succumbed to infection. Despite their old age, all vaccinated residents showed no or only mild disease. Comparison of the humoral immune response revealed significantly higher antibody levels in fully vaccinated infected individuals compared to fully vaccinated uninfected individuals (p < 0.001). Notably, although only a minority of the vaccinated uninfected group showed neutralisation capacity against SARS-CoV-2, all vaccinated and infected individuals showed high-titre neutralisation of SARS-CoV-2 including the alpha and beta variant. Large SARS-CoV-2 outbreaks can occur in fully vaccinated populations, but seem to associate with mild disease. SARS-CoV-2 infection in fully vaccinated individuals is a strong booster of the humoral immune response providing enhanced neutralisation capacity against immune evasion variants.

3.
Pathog Glob Health ; 115(5): 273-276, 2021 07.
Article in English | MEDLINE | ID: covidwho-1262047

ABSTRACT

Currently vaccines protecting from COVID-19 are a scarce resource. Prioritising vaccination for certain groups of society is placed in a context of uncertainty due to changing evidence on the available vaccines and changing infection dynamics. To meet accepted ethical standards of procedural justice and individual autonomy, vaccine allocation strategies need to state reasons for prioritisation explicitly while at the same time communicating the expected risks and benefits of vaccination at different times and with different vaccines transparently. In this article, we provide a concept summarising epidemiological considerations underlying current vaccine prioritisation strategies in an accessible way. We define six priority groups (vulnerable individuals, persons in close contact with the vulnerable, key workers with direct work-related contact with the public, key workers without direct work-related contact to the public, dependents of key workers and members of groups with high interpersonal contact rates) and state vaccine priorities for them. Additionally, prioritisation may follow non-epidemiological considerations including the aim to increase intra-societal justice and reducing inequality. While national prioritisation plans integrate many of these concepts, the international community has so far failed to guarantee equitable or procedurally just access to vaccines across settings with different levels of wealth.


Subject(s)
COVID-19 , Vaccines , COVID-19 Vaccines , Humans , SARS-CoV-2 , Vaccination
4.
Eur J Clin Microbiol Infect Dis ; 40(5): 1063-1071, 2021 May.
Article in English | MEDLINE | ID: covidwho-1061091

ABSTRACT

Evaluation and power of seroprevalence studies depend on the performed serological assays. The aim of this study was to assess four commercial serological tests from EUROIMMUN, DiaSorin, Abbott, and Roche as well as an in-house immunofluorescence and neutralization test for their capability to identify SARS-CoV-2 seropositive individuals in a high-prevalence setting. Therefore, 42 social and working contacts of a German super-spreader were tested. Consistent with a high-prevalence setting, 26 of 42 were SARS-CoV-2 seropositive by neutralization test (NT), and immunofluorescence test (IFT) confirmed 23 of these 26 positive test results (NT 61.9% and IFT 54.8% seroprevalence). Four commercial assays detected anti-SARS-CoV-2 antibodies in 33.3-40.5% individuals. Besides an overall discrepancy between the NT and the commercial assays regarding their sensitivity, this study revealed that commercial SARS-CoV-2 spike-based assays are better to predict the neutralization titer than nucleoprotein-based assays are.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19/diagnosis , COVID-19/epidemiology , SARS-CoV-2/isolation & purification , Adolescent , Adult , Aged , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/blood , COVID-19 Serological Testing/standards , Contact Tracing , Female , Humans , Immunoassay , Male , Middle Aged , Neutralization Tests , Prevalence , SARS-CoV-2/immunology , Sensitivity and Specificity , Young Adult
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