The study demonstrates the importance of the second dose of vaccine and the updating of vaccines to combat new variants of concern

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New research presented at this year’s European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) shows the importance of receiving the second dose of a COVID-19 vaccine and also the need to constantly review and update vaccines to address new variants of concern. Nicole Schneiderhan-Marra, Institute of Medical and Natural Sciences, University of Tübingen, Reutlingen, Germany, and her colleagues conducted the study.

Although vaccines have begun to control the pandemic in certain countries, it is not yet clear to what extent these vaccines will be effective as the virus mutates and evolves. The protection generated against the virus by vaccination is usually measured by antibodies, of particular importance a certain group called “neutralizing antibodies”, as they defend the body and destroy the virus.

Because the current generation of vaccines was designed against the original strain of the virus (known as the “wild type”), they offer maximum protection against this strain. However, it is not yet clear whether protection will remain the same against new strains of the virus, such as alpha (Kent / UK), beta (South Africa) delta (India) or gamma (Brazil) variants.

See how the protection it offers works changed by different variants, the researchers first profiled the antibodies generated by vaccination and then examined their neutralizing capacity. In addition to the antibodies circulating in the blood, they checked for the presence of antibodies in the saliva as a “first line of defense.”

To do so, they adapted a previously developed assay that measures the antibodies present against SARS-CoV-2 and other coronaviruses in the blood, to include targets of worrying variants and to look specifically at neutralizing antibodies. They collected samples from 23 vaccinated individuals (26 to 58 years, 22% women) who had been vaccinated with the Pfizer BioNTech vaccine after the first and second dose. For the control groups, the team also collected samples from 35 infected (40-78 years, 29% women) 27 infected saliva donors (25-58 years, 63% women) and 49 uninfected saliva donors (25-38 years, 55% women) and also monitor blood samples and saliva comes commercially from before the pandemic.

When they looked at the saliva, they saw that vaccinated individuals had large amounts of antibodies compared to infected individuals, suggesting that vaccination not only provides protection against infection, but that if you become infected, it reduces the chance of transmitting. -to other people.

The number of antibodies produced and the protection offered by vaccination increased substantially after the second dose of vaccine was given, showing the importance of receiving the second dose. At the time of the study, the two global variants of concern were the alpha and beta variants, so they examined whether the protection offered against these two variants was similar or different from that offered against the ” wild type “. They found that while there was no reduction in neutralizing antibodies against the alpha variant, there was a substantial reduction in neutralizing antibodies against the beta variant. “This demonstrates the importance of constantly updating vaccines to provide maximum protection against different strains of the virus,” explains Dr. Schneiderhan-Marra.

Since this study was completed, the virus has continued to mutate, with the delta variant now the dominant strain worldwide. As a result, researchers have developed their trials to include more targets from worrying variants such as delta (India) and gamma (Brazil), along with other variants of interest (eta, iota, zeta, theta, kappa and epsilon), and other interesting strains such as the mink mutation discovered last year.

Dr Schneiderhan-Marra says: “However, two more questions remain about vaccination: firstly, what protection do current delta vaccines offer and any other variants that may arise in the future, and secondly, how much how long does the protection offered by current vaccines last and will you need a booster shot not only to increase overall protection but also to offer protection against new variants? “

Your team is working , one of which includes the donors themselves in this study and how the protection they received from the vaccine changes throughout the year. Another study studies neutrality they differ between different vaccines and finally other studies study other variants and their impact on protection.


COVID-19: How vaccines against the Delta variant work


More information:
Matthias Becker et al, Immune response to SARS-CoV-2 concern variants in vaccinated individuals, Communications on Nature (2021). DOI: 10.1038 / s41467-021-23473-6

Matthias Becker et al, Exploring beyond the clinical routine of SARS-CoV-2 serology using MultiCoV-Ab to assess cross-reactivity of endemic coronavirus, Communications on Nature (2021). DOI: 10.1038 / s41467-021-20973-3

Provided by the European Society of Clinical Microbiology and Infectious Diseases

Citation: The study shows the importance of the second dose of vaccine and the update of vaccines to combat new variants of concern (2021, July 10) recovered on July 11, 2021 at https://medicalxpress.com / news / 2021-07-importance-vaccine-dose-vaccines-combat.html

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