In a recent study conducted by John Hopkins University, it was found that CD4+TLymphocytes last for more than six months in people who have received mRNA Covid vaccine. They mentioned that immune system cells which are also known as T cells produced by people who have received Pfizer or Moderna vaccine last for a period of approximately 6months and provide protection against the Covid infection.
The level of T cells went a little lower than they were after 2 weeks of vaccination. Surprisingly the helper T cells were still higher than any unvaccinated person.
“Previous research has suggested that humoral immune response where the immune sytem circulates virus-neutralising antibodies can drop off at six months after vaccination , whereas our study indicates that cellular immunity where the immune system directly attacks the infected cells remains strong” said Joel Blankson, MD, PhD, professor of Medicine at the John Hopkins University School of Medicine .
This study was conducted on 15 participants at three different occasions. Blood samples were collected from these patients once before vaccination, once 7-14 days after the second dose of vaccination and once 6months after the vaccination. The average age of the participants was 41 and there was participation of both men and women.
The study found that the number of helper T cells was low prior to vaccination, this frequency rose to much higher levels in 7-14 days of vaccination. These levels dipped to almost half after 6months of vaccination. These numbers were still significantly higher than the numbers obtained before vaccination.
