MedLife Announces Preliminary Results of First Study in Romania on the Evolution of Post-Vaccination Antibodies Against COVID-19 – Essential

In this first stage of the study, carried out by MedLife’s research division, a sample of 179 people, medical and auxiliary personnel, from 24 to 79 years old, were analyzed, from whom biological samples were collected for the detection of antibodies. – IgG nucleocapsid in Abbott Alinity and anti-SARS-CoV-2 peak IgG antibodies in Liason Diasorin after the first dose of vaccine and after the second dose, respectively. The equivalence studies carried out by the manufacturers with the Liason Diasorin quantitative method concluded that those concentrations that are> = 80 AU / ml correspond to neutralizing antibody titers> = 1: 160 (PRNT). In the absence of an anti-SARS-CoV-2 antibody concentration standard and no neutralized antibody titer to indicate the level of protection, the results of serological tests are interpreted with caution, assuming that the higher the concentration of antibodies to binding, the range established by the manufacturer, it is assumed that there is a higher neutralizing antibody titer, especially in the case of anti-S antibodies.

Company representatives announce their intention to increase the sample to 1,000 people, so that the information offers greater scientific value. Antibodies will be tested 20 days after the first dose of vaccine and 10-14 days after the second dose. The evaluation will continue and the data will be analyzed at 3 and 6 months after vaccination, respectively.

Of the total number of people enrolled in this stage of the study, 142 tested negative for PCR before the first dose of vaccine, 33 had a positive RT-PCR test between May and December 2020, and 4 tested positive after the first dose of vaccine.

Taking into account the profile of people who had not been previously infected, it was found that the immune response is low before the boost, so that only in 20% of the people concentrations> = 80 AU / ml were determined, being these in the range 15 to 21 days after the first dose of vaccine. However, the percentage doubles in the first days after the boost. As a result, in 42% of people who have not been infected with the SARS-CoV-2 virus to date, anti-Spike antibodies have developed at concentrations> = 80 AU / ml in the first 6 days of the second dose. Furthermore, the percentage of those who developed neutralizing antibodies increases significantly and approaches 100% among people at the time of evaluation within 7-10 days after the booster dose. On the other hand, MedLife specialists draw the agency’s attention to the fact that two people in this sample did not develop antibodies even in the first 6 days after the booster dose.

People who have been through the disease develop a significantly higher antibody titer even in the first few days after the vaccine.

Regarding the sample of people diagnosed with COVID-19 in the past, it was observed that the antibody titer developed is significantly higher than in those who were not infected, even from the first days after vaccination. Of the total of 33 people in this sample, only one did not develop antibodies in the first 7 days. When comparing people between 1 and 6 days after the booster dose, MedLife specialists found that those who had the disease can develop a neutralizing antibody titer more than 10 times higher.

“We believe that vaccination is the most effective solution to combat the pandemic, that is why we provide our own research resources to monitor the immune response to the vaccine, both in the short, medium and long term. At this stage we have preliminary results, based on a small sample, but the scientific value will increase once we exceed the threshold of 1000 people analyzed. However, the premises are good, given that both people who have had the COVID infection and those who have not had the disease previously develop antibodies after taking both doses. We will continue to closely monitor the evolution of post-vaccination antibodies in order to inform the authorities in due time about the period in which the neutralizing antibody titer is maintained and when it begins to decrease, ”said Mihai Marcu, President and CEO. from MedLife Group.

Post-Vaccine Antibodies and Natural Antibodies

Experts explain that the antibodies obtained from infection with the SARS-CoV-2 virus are different from those obtained from vaccination. As a result of COVID-19 infection, both N-binding (nucleocapsid) and anti-S (spike) antibodies can be detected. In contrast, the vaccines only induce the production of anti-S antibodies, their dosage in the blood may give different results depending on the analytical platform used, respectively the component in antigenic determinants of the respective kits.

Post-vaccination evolution and anti-SARS-CoV-2 antibody measurement was performed using one of the most advanced and high-throughput immunological test methods. The MedLife laboratory has the possibility to perform three types of antibody detection tests, all three by the chemiluminescence principle: anti-S IgM Ac, Alinity-Abbott quality test, anti-N IgG Ac, Alinity-Abbott quality test and Anti-S IgG Needle, quantitative test in the Liaison – Diasorin system, with approximate equivalence in the neutralization titer. All antibody tests are also available upon request for both patients and businesses.

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MedLife’s research efforts continue, both in terms of post-vaccination antibody titer evolution and virus evolution. “We will continue to monitor and inform the authorities both about the mutations that the virus can suffer and about the evolution of the post-vaccination antibody titer, so that we can adapt at the appropriate time,” added Mihai Marcu.

The study on the post-vaccination immune response of the body against COVID-19, the first of its kind in Romania, is the seventh carried out pro bono by the market leader of private medicine, among the topics of previous research is the immunization population. dynamics, both nationally and locally (Suceava), the dynamics of naturally acquired antibodies in infected patients, but also the sequencing of the SARS-CoV-2 virus genome, the last preliminary conclusions being communicated a week ago.