Latest News !!! Current Covid Vaccine Protects Against Delta's Severe Consequences, Omicron: Study

The Beth Israel Deaconess Medical Center (BIMC) team in Israel evaluated a sample of 47 people who were vaccinated with either the Johnson & Johnson or Pfizer-BioNTech vaccine.

Jerusalem: Current COVID-19 vaccination provides strong protection against severe illness and hospitalization caused by the Delta and Omicron variants, according to a study.

A study published in the journal Nature on Monday showed that vaccination induces this protection through cellular immunity, or the production of protective immune cells such as so-called killer cells and memory cells.

The researchers say that cellular immunity continues to protect against severe COVID-19 disease even though the Omicron variant evades neutralizing antibodies.

The Beth Israel Deaconess Medical Center (BIDMC) team in Israel evaluated samples from 47 people vaccinated with either the Johnson & Johnson or Pfizer-BioNTech vaccine.

"Our data provide an immunological context for observing that current vaccines continue to provide strong protection against severe illness and hospitalization due to the Omicron variant, despite a significant reduction in neutralizing antibody response and an increase in breakthrough infection," said related author Dan H. Barush.

The researchers used samples from uninfected people who had received either the Johnson & Johnson or Pfizer vaccines.
They measured the response of CD8+ T cells and CD4+ T cells to the original Delta and Omicron SARS-CoV-2 strain for one month and then eight months after the final vaccination.
CD4 and CD8 cells, also known as T cells, are white blood cells that fight infection and play an important role in the immune system.
The team also assessed antibody response to variants at one and eight months. In line with previous research, the scientists found a minimally reactive cross-neutralizing antibody that is specific for Omicron.
In contrast, the data show that the Omicron-specific CD8+ T-cell response is more than 80% cross-reactive compared to the CD8+ T-cell response to the host viral strain.
Similarly, more than 80% of Omicron-specific CD4+ T cells showed cross-reactivity, although responses may vary from person to person, the researchers noted.
"Given the role of CD8+ T cells in clearing viral infection, it is likely that cellular immunity makes a significant contribution to vaccine protection against severe SARS-CoV-2 disease," said Barush, whose team was involved in the development of the Johnson and Johnson vaccine. .
"This may be especially true for Omicron, which drastically evades the neutralizing antibody response," he said. .
This is due to its ability to evade virus-killing neutralizing antibodies that the body produces in response to vaccination.
This report is generated automatically by PTI News Service. ThePrint is not responsible for its contents.

Overview

Cellular immunity is an immune response that does not include antibodies, but includes the activation of phagocytes, specific cytotoxic T lymphocytes, and the release of various cytokines in response to antigens.

Historically, the immune system has been divided into two branches: humoral immunity, in which the protective function of immunization can be found in humor (biological fluid or cell-free serum), and cellular immunity, in which the protective function of immunity lies in cell-bound. . CD4 cells or T-helper cells provide protection against various pathogens. Naive T cells, mature T cells that never encounter an antigen, turn into active effector T cells when they encounter antigen presenting cells (APCs).

These APCs, like macrophages, dendritic cells, and B cells under some circumstances, load antigenic peptides onto MHC cells, in turn presenting the peptides to receptors on T cells. The most important of these APCs are highly specialized dendritic cells; conceivably operate solely to ingest and present antigen.

Activated Effector T cells can be assigned to three functional classes, detecting peptide antigens derived from different types of pathogens: The first class is cytotoxic T cells, which kill target cells infected by apoptosis without the use of cytokines, the second class is TH1 cells, which mainly function to activate macrophages, and the third class is TH2 cells, whose main function is to stimulate B cells to produce antibodies.

The innate immune system and the adaptive immune system consist of humoral and cell-mediated components, respectively.

Cellular immunity protects the body by:

Cells such as killer T cells, macrophages, natural killer cells among the immunological reactions that eliminate pathogens themselves, virus-infected cells, cancer cells, etc. This is referred to as humoral immunity (humoral immunity), where the subject of elimination is antibodies in body fluids. Delayed responses such as rejection reactions and contact dermatitis after organ transplantation are also cellular immunity. → lymphocyte / allergy

Pfizer Covid-19 Vaccine

On July 14, 2021, the POM has issued the EUA for one type of Covid-19 vaccine developed on the mRNA platform, namely the Comirnaty Vaccine produced by Pfizer and BioNTech. Based on phase 3 clinical trial data, the efficacy of Pfizer's Covid-19 vaccine at the age of 16 years and over showed 95.5% success.

Meanwhile, the efficacy of Pfizer's Covid-19 vaccine in adolescents aged 12-15 years is 100 percent. Immunogenicity data also showed that administration of 2 doses of Comirnaty vaccine at 3 weeks interval resulted in a good immune response. As vaccines with mRNA platforms that have special storage specifications using ultra low temperatures, namely at -90 to -60 degrees Celsius.

The reactions or side effects that most often arise from the use of the Pfizer vaccine include pain at the injection site, fatigue, headache, muscle aches, chills, joint pain, and fever.