The document discusses how T cells, unlike antibodies, provide long-lasting immunity against COVID variants even as the virus mutates. While antibodies target specific proteins of the virus, T cells mount a broader response that protects against severe illness from new variants. Experts say widespread T cell buildup through vaccination and infection has led to typically milder cases of current Omicron subvariants spreading in the US. T cells are described as the "unsung heroes" that help shelter people from the worst effects of COVID when antibodies can no longer prevent infection. Their role suggests herd immunity may be developing as new variants encounter increasing T cell protection in the population.

1. There is a benefit to COVID reinfection that could
help to control the pandemic.
Not just the temperatures are increasing rapidly at
the moment.
It's the summer of reinfection, and an extremely
contagious, immune-evading subvariant makes
getting COVID more likely than ever. These
variations have transformed what should have
been a carefree, enjoyable summer into yet
another oppressive season that must be
endured—with little chances for relief, even
outside.
On the chart from the US Centers for Disease
Control and Prevention, diseases are depicted as
a long wave (or wall? However, wastewater data,
which may currently be our best measure of
COVID in communities, refutes those figures. As
of this week, around to 50% of sewage testing
locations nationally reported COVID levels
between 60% and 100% of their all-time h

2. The good news is that T cells, the frequently
disregarded and poorly known other half of the
immune system, will still have to contend with
COVID mutations even if they manage to elude
antibody defense.
While antibodies, specialized proteins made by
the immune system, look for pathogens and
disable or destroy them, they are normally only
effective for a few months at a time. They attach
to a particular component of a virus that could be
altered by new versions, potentially decreasing
their effectiveness.
T cells, a subset of white blood cells generated by
bone marrow stem cells, cannot fight off
infections. However, they can significantly lessen
the severity of one, making it a potentially fatal
illness.

3. They continue to fight even when the virus
mutates and changes shape since their response
isn't restricted to a single area of the infection,
unlike antibodies. Additionally, its protection is
significantly more resilient and, in some situations,
is known to persist for years. According to
experts, widespread buildup of T cells in the
community through vaccination and/or infection
has probably resulted in typically less severe
results for the novel variations that are sweeping
the nation.
According to Dr. Duane Wesemann, a professor
at Harvard Medical School and a principal
investigator in the Division of Rheumatology,
Immunology, and Allergy at Brigham and
Women's Hospital, "T cells are kind of a win that I
don't believe is acknowledged as much as they
should be." They "aren't quite silver."
bullet, but one that is already in our possession
and has proven effective for us.

4. Because everyone is becoming infected with new
variants, society is "a little bit depressed,"
according to Wesemann. However, T cells are still
active and working to prevent serious illness.
The frequently overlooked second half of the
immune system
There have been numerous reinfections caused
by new COVID subvariants like BA.4 and BA.5,
which are currently sweeping the country. This
includes vaccinated people who were recently
infected by a different subvariant.
However, when we discuss immune-evading
variations, we are actually only discussing
antibody immunity, and this is only half of the
issue. There is a whole other aspect of immunity
that is understudied, in part because T cells are
less well understood and more challenging to
examine.

5. T cells are the "unsung heroes" of the pandemic,
according to Ekaterina Pesheva of Harvard
Medical School, who claims that they "have
played a vital role in sheltering us from the worst
ravages of COVID-19."
T cells step in to the rescue, she says, "when
antibodies fail to prevent the virus from entering
our cells." "If T cells are the elite guards inside the
castle, then antibodies are the rampart around it
that deters attackers from
entering,"successfully sneak in."
This suggests that our innate immune response to
COVID and vaccinations has been significantly in
fluenced by T cells.

6. We rely on antibodies to stop infections, but if
someone contracts an infection, "those T cells can
attenuate the course of the disease in what can
be a very dramatic way," said Dr. Bruce Walker,
co-leader of the Massachusetts Consortium on
Pathogen Readiness and director of the Ragon
Institute of MGH, MIT, and Harvard, a medical
center dedicated to curing disease.
According to a study published this spring in the
journal Nature Immunology, COVID infection
results in a "robust" T-cell response that lasts for
at least 15 months.
And in individuals who had already been infected
17 years earlier, a 2020 study published in Nature
discovered signs of T-cell response to another
coronavirus, SARS (severe acute respiratory
syndrome), an outbreak that broke out in 2002
and claimed hundreds of lives.
Herd Reconsidered immunity
According to Dr. Amesh Adalja, a senior scholar

7. at the Johns Hopkins Center for Health Security,
new subvariants like BA.4 and BA.5 are
progressively coming up against a wall of T-cell
based protection in the general population.
Adalja stated that immunity is a spectrum that
ranges from merely protecting against death,
hospitalization, and severe infection, to preventing
infection altogether. For severe disease, however,
the T-cell immunity is very, very important and is
not something you can just get around.
He predicted that during the BA.4 and BA.5 wave,
hospitalizations will increase. "But will they grow
too big to handle? The US has made it harder for
COVID to accomplish that.
Similar to how T cells "are actually what's going

8. to change this epidemic into something more
controlled," Walker believes this to be true.
We've observed that, in general, the virulence of
the disease has not been as significant as these
new varieties are emerging and people are being
exposed to and infected, he said earlier this
month. "I believe a large portion of that is due to
the fact that folks have produced some sort of T-
cell response," the author says.
"More transmission has been taking place for
weeks, yet hospital admissions haven't
skyrocketed. I believe it illustrates how the
epidemic has lost some of its wind, at least for the
time being.
Originally published on Fortune.com, this article