Pfizer-BioNTech, Modern jabs show better immunity

study published in clinical infectious disease The journal showed that the helper T cells dropped to only slightly below levels seen over six months, two weeks after vaccination; Also, this level was significantly higher in people who were not vaccinated.

According to the US Centers for Disease Control and Prevention, the delta variant, which is currently the dominant strain of SARS-CoV-2 worldwide, causes more infections and spreads faster than older variants of the virus.

“Previous research suggested that the humoral immune response, where the immune system transmits virus-neutralizing antibodies, may stop six months after vaccination, whereas our study indicates that cellular immunity, where the immune system directly attacks infected cells, stays strong,” he said. Joel Blankenson, professor of medicine at the Johns Hopkins University School of Medicine and a senior author of the study.

“The persistence of these vaccine-elicited T cells, along with the fact that they are active against the delta variant, has important implications for guiding COVID-19 vaccine development and determining the need for future COVID-19 boosters,” he said.

Blankenson and colleagues obtained blood samples from 15 study participants (10 men and five women) over three time periods: before vaccination, between seven and 14 days after their second Pfizer-BioNTech or Moderna vaccine dose, and six months after vaccination. after. Participants had a mean age of 41 years and none had evidence of prior SARS-CoV-2 infection.

CD4+ T lymphocytes, or helper T cells, assist another type of immune system cell, the B lymphocyte (B cell), to respond to surface proteins (antigens) on viruses such as SARS-CoV-2. Activated by CD4+ T cells, immature B cells become either plasma cells that produce antibodies to mark infected cells for disposal from the body, or memory cells that respond rapidly to future infections. “Remembers” the biochemical structure of the antigen.

Therefore, a CD4+ T cell response can serve as a measure of how well the immune system responds to a vaccine and produces humoral immunity.

The researchers also looked at the ability of CD4+ T cells six months after vaccination to recognize the spike protein above the SARS-CoV-2 delta variant. They found that the number of T cells that recognized the delta variant spike protein was not significantly different from that of T cells bound to the protein of the original virus strain.

“Strong expansion of T cells in response to stimulation with spike proteins is definitely indicated, supporting the need for more studies to show booster shots increase the frequency of SARS-CoV-2-specific T cells circulating in the blood.” successfully increases,” said Blankenson. “The added bonus is finding that this response is likely to be stronger for the delta version as well.”

In its latest weekly epidemiological update, the World Health Organization (WHO) said that the delta variant of the SARS-CoV-2 virus has shown prominence globally, based on publicly available datasets or data submitted to WHO for reported detection. The prevalence of other variants has declined among sequences. United Nations Health Agency said.

The Delta variant, which was first discovered in India, is now present in over 104 countries.

India is expected to release vaccines from Pfizer and Moderna soon for its nationwide vaccination campaign. “The number of fully vaccinated individuals has crossed the partially vaccinated population for the first time in the country. Union Minister of Health and Family Welfare Mansukh Mandaviya said, “India has administered 67,82,042 vaccine doses in the last 24 hours with a total of over 1.13 billion doses as of 7 am today (Wednesday) provisional report.” By the end of the month, the country will vaccinate every Indian knock every house campaign,” he said.