A single dose of the Sputnik V vaccine may elicit significant antibody responses against SARS-CoV-2, finds a study published July 13 in the journal Cell Reports Medicine.
“Due to limited vaccine supply and uneven vaccine distribution in many regions of the world, health authorities urgently need data on the immune response to vaccines to optimize vaccination strategies,” says senior author Andrea Gamarnik (@GamarnikLab) of the Fundación Instituto Leloir-CONICET in Buenos Aires, Argentina. “The peer-reviewed data we present provide information for guiding public health decisions in light of the current global health emergency.”
Past research has shown that two doses of Sputnik V results in 92% efficacy against coronavirus disease 2019 (COVID-19), which is caused by SARS-CoV-2. An important question is whether a single dose would achieve greater public health benefit than two doses by allowing protection of a larger population more quickly.
Continue reading “One shot of the Sputnik V vaccine triggers strong antibody responses”
New research has shown that early testing for blood clots in patients who had received the AstraZeneca/Oxford vaccine led to them being treated successfully, highlighting the need for heightened awareness of the risk among doctors.
The work, led by researchers from RCSI University of Medicine and Health Sciences and the National Coagulation Centre at St James’s Hospital, is published in the British Journal of Haematology.
Continue reading “Blood clots related to AstraZeneca/Oxford vaccine can be mitigated with early detection”
A rare syndrome has been observed in people following vaccination against Covid-19. This involves thrombosis at unusual sites in the body, associated with a low thrombocyte (blood platelet) count and a clotting disorder. In medical jargon, this syndrome is referred to as VITT (vaccine-induced thrombotic thrombocytopenia). Doctors at the Department of Medicine I of MedUni Vienna and Vienna General Hospital (Division of Hematology and Hemastaseology) have now successfully treated an acute instance of this syndrome.
VITT is most probably caused by a defective immune response, whereby thrombocyte-activating antibodies are produced resulting in thrombocytopenia (low platelet count) and thrombosis. The mortality rate in VITT is high (40-50 %) and the syndrome requires immediate and appropriate treatment. However, the current recommendations are only empirical and are based on in-vitro data.
A team of doctors at the Department of Medicine I of MedUni Vienna and Vienna General Hospital, led by coagulation specialist Paul Knöbl, has now successfully treated a patient suffering from vaccine-induced prothrombotic immune thrombocytopenia (VIPIT). The female patient was admitted to the Department with a low platelet count and low fibrinogen levels. Fibrinogen is a protein that plays a major role in blood clotting. Knöbl reports: “Apart from that, her D-dimer values, which indicate thrombosis, were very high and an ELISA assay produced a clear positive result for heparin-PF4 antibodies – all signs of incipient thrombosis.”
The doctors acted quickly, and the patient responded immediately to treatment with a high dose of intravenous immunoglobulin concentrates, cortisone and specific anticoagulants, so that thrombosis was prevented. Immunoglobulin concentrates contain antibodies that can block the misdirected immune response. The usual heparin preparations must not be used to prevent clotting, since they can trigger thrombosis, or aggravate it.
“In this case we were able to describe, for the first time, the efficacy of a potentially life-saving treatment strategy for vaccine-induced thrombosis,” says Knöbl. These new findings have been published in the Journal of Thrombosis and Haemostasis. On the one hand, the findings support the current treatment recommendations, but they also show that prompt diagnosis and immediate initiation of treatment are necessary in order to prevent a life-threatening thrombosis. “This experience could be of great help in treating other patients with similar conditions.”
Testing and vaccination – these are the pillars on which humanity is trying to get a grip on the Coronavirus pandemic. Although it is taking longer than many had expected, it is believed that it is only a matter of time before we are all vaccinated and thus protected. However, time is also working for the virus, which has now mutated several times, with variants B.1.1.7 from the United Kingdom, B.1.351 from South Africa and P.1 from Brazil spreading rapidly. These viruses have mutations in the so-called spike protein, the structure on the surface of the virus that is responsible for attachment to host cells. At the same time, the spike protein is also the major target of the immune response. Antibodies generated in response to SARS-CoV-2 infection or vaccination bind to the spike protein, thereby blocking the virus. A team led by Markus Hoffmann and Stefan Pöhlmann of the German Primate Center – Leibniz Institute for Primate Research and Jan Münch of the Ulm University Medical Centre has found that the SARS-CoV-2 variants B.1.351 and P.1 are no longer inhibited by an antibody used for COVID-19 therapy. In addition, these variants are less efficiently inhibited by antibodies from recovered patients and vaccinated individuals. Thus, convalescence from COVID-19 as well as vaccination may offer only incomplete protection against these mutant viruses (Cell).
Continue reading “Evidence for reduced antibody protection against SARS-CoV-2 variants”
Results from a large clinical trial in the United States and South America indicate that AstraZeneca’s COVID-19 vaccine, AZD1222, is well-tolerated and protects against symptomatic COVID-19 disease, including severe disease or hospitalization. The independent Data and Safety Monitoring Board (DSMB) overseeing the trial identified no safety concerns related to the vaccine. The United Kingdom-based global biopharmaceutical company AstraZeneca developed the vaccine and led the trial as regulatory sponsor.
The National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and the Biomedical Advanced Research and Development Authority (BARDA), part of the U.S. Department of Health and Human Services’ Office of the Assistant Secretary for Preparedness and Response, provided funding support for the trial through the federal COVID-19 response.
Continue reading “Investigational AstraZeneca vaccine prevents COVID-19”