SHARE ON: |
| |
| |
 |
 |
|
|
The emergence of coronavirus variants has provoked concern about their impact on the effectiveness of vaccines, and whether people who were previously infected might be more susceptible to reinfection.
But in welcome news, a new study on Tuesday showed that a key player in the immune response, called the killer T cell, remained mostly unaffected.
The finding is encouraging because although these white blood cells are not a first line defense against infection, they can help prevent severe disease.
Scientists at the National Institutes of Health and Johns Hopkins University analyzed blood samples from 30 people who had contracted and recovered from COVID-19 prior to the emergence of variants.
They published their findings in Open Forum Infectious Diseases, an Oxford University Press journal.
The team wanted to know whether these cells, known by their technical name CD8+ T cells, could still recognize three variants of SARS-CoV-2: B.1.1.7, first found in Britain, B.1.351, identified in South Africa, and B.1.1.248, first seen in Brazil.
What makes each of these variants unique is the mutations they carry, especially in a region of the virus spike protein, structures that stud its surface and allow it to invade cells.
It has already been shown that mutations to this region of the spike protein make some variants less recognizable to neutralizing antibodies -- infection fighting proteins produced by the immune systems B cells.
This seems to be particularly true, for instance, of B.1.351, according to research on the impact of current generation COVID-19 vaccines.
Neutralizing antibodies are custom-made to fit an antigen, or a specific structure of a pathogen.
In the case of the coronavirus, this is the spike protein, which the antibodies bind to, preventing the virus from infecting cells.
Killer T cells, on the other hand, look for telltale signs of cells that have already been infected with pathogens they have previously encountered, and then kill those cells.
In the new study, the researchers found that the killer T cell responses remained largely intact and could recognize virtually all mutations in the variants studied.
The researchers noted that larger studies are needed to confirm the results, but said that it nevertheless demonstrated that killer T cells are less susceptible to mutations in the coronavirus than neutralizing antibodies are.
Antibodies are still important to prevent infection in the first place -- and the reduced efficacy of vaccines to the variants seems to be evidence of this.
But a killer T cell response that kicks in later and aids in clearing off the disease, helps explain why the vaccines seem to be able to prevent severe disease and hospitalization, even though their efficacy at stopping infection by variants is reduced.
|
 |
|
 |
|
 |
|
 |
5 pm |
| 34 ℃ |
| BROKEN CLOUDS |
WIND: WNW 21 KM/H
GUSTING TO 32 KM/H |
|
|
|
6 pm |
| 34 ℃ |
| BROKEN CLOUDS |
WIND: WNW 16 KM/H
GUSTING TO 31 KM/H |
|
|
|
7 pm |
| 32 ℃ |
| BROKEN CLOUDS |
WIND: N 10 KM/H
GUSTING TO 15 KM/H |
|
|
|
8 pm |
| 30 ℃ |
| BROKEN CLOUDS |
WIND: NE 10 KM/H
GUSTING TO 9 KM/H |
|
|
 |
9 pm |
| 26 ℃ |
| SCATTERED CLOUDS |
WIND: E 10 KM/H
GUSTING TO 10 KM/H |
|
|
|
10 pm |
| 23 ℃ |
| SCATTERED CLOUDS |
WIND: ESE 16 KM/H
GUSTING TO 20 KM/H |
|
|
 |
11 pm |
| 20 ℃ |
| LIGHT RAIN |
WIND: SE 13 KM/H
GUSTING TO 16 KM/H |
|
|
|
12 am |
| 21 ℃ |
| SCATTERED CLOUDS |
WIND: W 18 KM/H
GUSTING TO 30 KM/H |
|
|
|
 |
TODAY |
HIGH OF 34 ℃
LOW OF 16 ℃ |
| LIGHT RAIN |
|
|
|
FRIDAY |
HIGH OF 33 ℃
LOW OF 12 ℃ |
| LIGHT RAIN |
|
|
 |
SATURDAY |
HIGH OF 38 ℃
LOW OF 14 ℃ |
| CLEAR SKY |
|
|
|
SUNDAY |
HIGH OF 36 ℃
LOW OF 21 ℃ |
| LIGHT RAIN |
|
|
|
MONDAY |
HIGH OF 32 ℃
LOW OF 17 ℃ |
| CLEAR SKY |
|
|
|
TUESDAY |
HIGH OF 33 ℃
LOW OF 17 ℃ |
| CLEAR SKY |
|
|
|
WEDNESDAY |
HIGH OF 37 ℃
LOW OF 19 ℃ |
| CLEAR SKY |
|
|
|
THURSDAY |
HIGH OF 32 ℃
LOW OF 18 ℃ |
| CLEAR SKY |
|
|
|
|
|
|
 |
 |
BLAKE SHELTON
STRANGERS
05:00 PM |
|
 |
DYLAN MARLOWE
COMING HOME TOMORROW
04:54 PM |
|
 |
SAM GROW
WAY IM LIVING
04:52 PM |
|
 |
RILEY GREEN
RATHER BE
04:49 PM |
|
 |
GORD BAMFORD
WHEAT KINGS
04:43 PM |
|
 |
JOSH TURNER
HEATIN THINGS UP
04:40 PM |
|
 |
CHRIS JANSON
THE BRIDE
04:37 PM |
|
 |
RASCAL FLATTS
I DARE YOU
04:32 PM |
|
 |
THOMPSON SQUARE
YOU MAKE IT LOOK SO GOOD
04:29 PM |
|
 |
SAMMI PALINKAS
THE LAST GIRL
04:25 PM |
|
 
 |
