C-VELVET [COVID-19]
Research type
Research Study
Full title
Convalescent Plasma Donor Vaccine Study. An observational antibody level study.
IRAS ID
296926
Contact name
Lise Estcourt
Contact email
Duration of Study in the UK
1 years, 0 months, 1 days
Research summary
Since the beginning of the COVID-19 pandemic scientists have been investigating the potential benefits of convalescent plasma in reducing the burden of the disease, in terms of prevention and treatment. A convalescent plasma collection strategy has been rolled out in the UK under the authority of the Department of Health and Social Care. A clinical study is underway to determine changes in antibody levels individuals who have previously donated COVID-19 convalescent plasma (CCP) and have now received at least one dose of a COVID-19 vaccine. These donors are no longer donating convalescent plasma as their virus-neutralising antibody levels aren’t at a high enough level. The study involves attending a fixed donation centre to give a blood sample. A cohort of registered NHSBT convalescent plasma donors will be invited to participate to the study; potential participants will be identified and approached by the NHSBT donor team to provide information. Participants will provide their consent before arranging a blood collection appointment at their local NHSBT donor centre. The aim of the study is to determine whether vaccination can induce adequate antibody levels to facilitate further collection of convalescent plasma.
Summary of results
In this study we investigated how plasma donors responded to different variants/strains of the SARS-CoV-2 virus after they had recovered from COVID-19 and been vaccinated against the virus. Plasma is the liquid part of blood that carries various important substances, including antibodies. We call the plasma from these donors “convalescent plasma”, as it was collected from individuals who have recovered from COVID-19. Studies have shown that convalescent plasma can help patients with a weakened immune system to fight the virus. We looked at how we can select the convalescent plasma that will be most effective in helping patients to recover from a COVID-19 infection.Various studies since the start of the COVID-19 pandemic have shown that successful treatment with convalescent plasma (CVP) requires plasma with a high level of antibodies that can fight (or “neutralise”) the virus. These antibodies are called “neutralizing antibodies” or “nAb” for short. Antibodies are produced by the body as part of its normal response to anything that is foreign or “non self” – in this case, the virus. In the 2022 study, we focussed on nAb that were effective against the Wuhan/wild type (WT), Alpha and Beta strains of SARS-CoV-2, as well as the recently emerging Delta and Omicron strains of the virus.
Blood samples were collected from voluntary plasma donors who had recovered from COVID-19 and then received one or two doses of the AstraZeneca or Pfizer COVID-19 vaccines. These individuals had donated convalescent plasma (CVP) in England via NHS Blood and Transplant. We measured the levels of nAb against different strains of the virus. We also wanted to see whether we could use an automated laboratory test to quickly tell us which CVP had the highest levels of nAb – and should therefore, offer the best treatment for patients. A total of 131 samples were tested from 94 CVP donors.
The key results were as follows1.
• Unvaccinated CVP donors had lower levels of neutralizing antibodies, especially against newer variants of the virus like Delta and Omicron.
• Vaccinated CVP donors showed higher levels of neutralizing antibodies against all strains after just one dose of the vaccine. Neither the type of vaccine, nor whether donors had received one or two vaccinations, made a difference to the results.
• CVP donations with the highest level of neutralizing antibodies were easily identified using a simple laboratory test. This allowed us to predict which plasma donations would provide the greatest benefit to patients with COVID-19.The results of this study agree with other research that shows that people who have recovered from a COVID-19 infection and then received a COVID-19 vaccination, have higher levels of the neutralizing antibodies that can fight off the virus.2,3,4 This helps to show why it is important for people to be vaccinated against COVID-19, even if they have already had the virus.
The findings can also help us to select the plasma that will provide the greatest benefit to patients, especially those with a weakened immune system. Other research has shown that convalescent plasma with high levels of neutralizing antibodies can improve recovery rates and reduce the number of patients that die from COVID-19 and its complications.5,6. Combining the body’s natural response to a viral infection with vaccination, provides the population with better protection against COVID-19 and its variants.
Key messages
• Vaccinating individuals who have recovered from COVID-19 boosts their antibody levels, making their plasma more effective against a wider range of variants or “strains” of the virus.
• An automated laboratory test to identify convalescent plasma donations with high levels of neutralizing antibodies provides the basis for us to collect the best plasma for treating patients on a much larger scale. This is crucial for maintaining the supply of convalescent plasma and allowing the heath service to act quickly when new variants of the virus are detected.References
1. Harvala H, Nguyen D, Simmonds P, Lamikanra AA, Tsang HP, Otter A, et al. Convalescent plasma donors show enhanced cross-reactive neutralizing antibody response to antigenic variants of SARS-CoV-2 following immunization. Transfusion. 2022;62(7):1347–54.
2. Saadat S, Rikhtegaran Tehrani Z, Logue J, Newman M, Frieman MB, Harris AD, et al. Binding and neutralization antibody titers after a single vaccine dose in health care workers previously infected with SARS-CoV-2. JAMA. 2021;325:1467–9.
3. Reynolds CJ, Gibbons JM, Pade C, Lin KM, Sandoval DM, Pieper F, et al. Heterologous infection and vaccination shapes immunity against SARS-CoV-2 variants. Science. 2022;375: 183–92.
4. Carreño JM, Alshammary H, Tcheou J, Singh G, Raskin A, Kawabata H, et al. Activity of convalescent and vaccine serum against SARS-CoV-2 Omicron. Nature. 2021;602:682–8.
5. Libster R, Pérez Marc G, Wappner D, Coviello S, Bianchi A, Braem V, et al. Early high-titer plasma therapy to prevent severe
COVID-19 in older adults. N Engl J Med. 2021;384:610–8.
6. Salazar E, Christensen PA, Graviss EA, Nguyen DT, Castillo B, Chen J, et al. Significantly decreased mortality in a large cohort of coronavirus disease 2019 (COVID-19) patients transfused early with convalescent plasma containing high-titer antisevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein IgG. Am J Pathol. 2021;191:90–107.REC name
West Midlands - Solihull Research Ethics Committee
REC reference
21/WM/0082
Date of REC Opinion
12 Apr 2021
REC opinion
Further Information Favourable Opinion