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.
|
 |
|
 |
|
 |
|
 |
11 am |
| 17 ℃ |
| VERY HEAVY RAIN |
WIND: SSE 12 KM/H
GUSTING TO 21 KM/H |
|
|
|
12 pm |
| 17 ℃ |
| LIGHT RAIN |
WIND: SSE 12 KM/H
GUSTING TO 22 KM/H |
|
|
|
1 pm |
| 17 ℃ |
| LIGHT RAIN |
WIND: WSW 9 KM/H
GUSTING TO 10 KM/H |
|
|
|
2 pm |
| 18 ℃ |
| HEAVY INTENSITY RAIN |
WIND: NW 13 KM/H
GUSTING TO 15 KM/H |
|
|
|
3 pm |
| 17 ℃ |
| HEAVY INTENSITY RAIN |
WIND: W 28 KM/H
GUSTING TO 32 KM/H |
|
|
|
4 pm |
| 16 ℃ |
| HEAVY INTENSITY RAIN |
WIND: WNW 32 KM/H
GUSTING TO 50 KM/H |
|
|
|
5 pm |
| 16 ℃ |
| HEAVY INTENSITY RAIN |
WIND: NW 27 KM/H
GUSTING TO 44 KM/H |
|
|
 |
6 pm |
| 15 ℃ |
| OVERCAST CLOUDS |
WIND: WNW 19 KM/H
GUSTING TO 38 KM/H |
|
|
|
|
TODAY |
HIGH OF 18 ℃
LOW OF 13 ℃ |
| VERY HEAVY RAIN |
|
|
|
MONDAY |
HIGH OF 15 ℃
LOW OF 10 ℃ |
| MODERATE RAIN |
|
|
 |
TUESDAY |
HIGH OF 24 ℃
LOW OF 11 ℃ |
| CLEAR SKY |
|
|
 |
WEDNESDAY |
HIGH OF 29 ℃
LOW OF 16 ℃ |
| SCATTERED CLOUDS |
|
|
|
THURSDAY |
HIGH OF 22 ℃
LOW OF 18 ℃ |
| MODERATE RAIN |
|
|
|
FRIDAY |
HIGH OF 28 ℃
LOW OF 16 ℃ |
| CLEAR SKY |
|
|
|
SATURDAY |
HIGH OF 30 ℃
LOW OF 18 ℃ |
| OVERCAST CLOUDS |
|
|
 |
SUNDAY |
HIGH OF 33 ℃
LOW OF 19 ℃ |
| FEW CLOUDS |
|
|
|
|
|
 |
 |
|
| MEL Science Back to School - Spark Curiosity! |
| |
| Make learning exciting with MEL Science! Explore hands-on STEM kits, experiments, and educational activities designed to inspire young minds. |
| |
| Back to School savings won’t last - start exploring today! |
|
 |
|
 |
|
|
 |
 |
JADE EAGLESON
PURE COUNTRY
11:00 AM |
|
 |
POST MALONE
GUY FOR THAT
10:57 AM |
|
 |
JASON ALDEAN
COUNTRY BOYS WORLD
10:53 AM |
|
 |
KEVIN FOWLER BAND
BEACH PLEASE
10:50 AM |
|
 |
ASHLEY COOKE
BABY BLUES
10:47 AM |
|
 |
RUSSELL DICKERSON
THOSE NIGHTS THESE DAYS
10:41 AM |
|
 |
LARRY FLEET
SOMEWHERE IN THE SOUTH
10:37 AM |
|
 |
CARLY PEARCE
DREAM COME TRUE
10:34 AM |
|
 |
TERRI CLARK
GIVIN UP GIVIN A DAMN
10:31 AM |
|
 |
BRETT YOUNG
YUKON
10:28 AM |
|
 
 |
