ABSTRACT
Background: The emergence of new SARS-CoV-2 variants raises concerns whether preexisting artificial (vaccine-induced) and natural immunity from prior COVID-19 prevents re-infections. Here, we investigated the differences in primary humoral immune response following SARS-CoV-2 variants of concern (VOCs) infection and aimed to identify the key mutations involved in these differences. Methods: Patients with primary PCR-proven SARS-CoV-2 infection with no history of previous COVID-19 vaccination were included between October 2020 and May 2021 at Amsterdam UMC and via the Dutch SARS-CoV-2 sequence surveillance program. Serum was collected 4-8 weeks after symptom onset and tested for IgG binding and pseudovirus neutralization of the wild-type (WT, Wuhan/D614G), Alpha, Beta and Delta variants. Results: We included 51 COVID-19 patients, who were infected with the WT (n=20), Alpha (n=10), Beta (n=9) or Delta variant (n=12). Generally, the highest neutralization titers were against the autologous virus. After stratifying for hospitalization status, non-hospitalized patients infected with the WT (ID50 817) or Alpha (ID50 2524) variant showed the strongest geometric mean autologous neutralization, followed by the Delta variant (ID50 704) infected participants. By contrast, only one participant infected with the Beta variant showed strong autologous neutralization (median ID50 171). The VOCs also differed in their ability to induce cross-neutralizing responses, with WT-infected patients showing the broadest immune response, followed by Alpha, Delta and Beta infected participants. Additionally, participants infected with the WT, Alpha or Delta variant showed the lowest cross-neutralization against the Beta variant, with a median 5.0-fold (2 to 16-fold), 7.7-fold (2 to 32-fold), and 5.3-fold (1 to 19-fold) reduction compared to the autologous neutralization, respectively. We identified the E484K mutation as the key mutation responsible for this low cross-neutralization. Conclusion: We demonstrated that even small differences in the S protein influences the polyclonal antibody response following infection. The low level of (cross-)neutralization induced by the Beta variant may implicate a higher re-infection risk, but further research of the memory B cell compartment and clinical studies are needed. The broadest cross-neutralizing response observed for WT-infected patients suggests that artificial immunity induced by the current approved COVID-19 vaccines already protects against many re-infections.
ABSTRACT
Late in 2020, two genetically-distinct clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with mutations of biological concern were reported, one in the United Kingdom and one in South Africa. Using a combination of data from routine surveillance, genomic sequencing and international travel we track the international dispersal of lineages B.1.1.7 and B.1.351 (variant 501Y-V2). We account for potential biases in genomic surveillance efforts by including passenger volumes from location of where the lineage was first reported, London and South Africa respectively. Using the software tool grinch (global report investigating novel coronavirus haplotypes), we track the international spread of lineages of concern with automated daily reports, Further, we have built a custom tracking website (cov-lineages.org/global_report.html) which hosts this daily report and will continue to include novel SARS-CoV-2 lineages of concern as they are detected.
ABSTRACT
Objectives: The emergence of Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012 was accompanied by uncertainty about its epidemiological and clinical characteristics. Once camelus dromedarius was found to be the natural reservoir of the virus public health systems across the Arabian Peninsula came under unprecedented pressure to control its transmission. This study describes how a One Health approach was used in Qatar to manage the MERS-CoV outbreak between 2012 and 2017. Method(s): The One Health approach adopted brought together professionals working in the health, animal welfare, and environmental sectors. To manage the MERS outbreak the Qatar National Outbreak Control Taskforce (OCT) was reactivated in November 2012 and experts from the animal health sector were invited to join. Later, technical expertise was requested from the WHO, FAO, CDC, Erasmus University (EMC), and Public Health England (PHE). A One Health roadmap was subsequently delivered addressing surveillance and investigation, epidemiological studies and increased local diagnostic capacity. Result(s): The joint OCT, once trained, was allocated resources and had access to high risk areas to gather evidence on the potential source of the virus and investigate all cases within 24-48 hours of reporting. Lack of sufficient technical guidance on veterinary surveillance and poor risk perception among vulnerable populations constituted major obstacles to maintaining systematic One Health performance. Conclusion(s): A One Health approach is essential for generating evidence and implementing control measures to restrain MERS-CoV and other zoonotic diseases.
ABSTRACT
Objective: To determine whether children play a role in the transmission of SARS-CoV-2 to other children and adults, and to gain insight into symptomatic and asymptomatic infections in children. Design: Analysis of national COVID-19 notifications and prospective observational study in families with children. Method: Information about COVID-19 patients and their contacts was obtained from the registration systems used by the public health services. In an ongoing study, patients with COVID-19 were asked to participate if they have a family with children. On two occasions nose-throat swabs and blood were collected for PCR analysis and determination of antibodies against SARS-CoV-2.