February 2022, ScientificAmerican.com 67their myeloma, those people who’ve [had] other treat-
ments or were failing their treatment—were much less
likely to respond” to COVID vaccination, Berenson says.
He is now studying the effect of additional vaccine
doses in multiple myeloma patients, and the results, he
says, are “shockingly promising.”
Antibody levels are only one part of immune pro-
tection, however. T cells and memory B cells also form
a critical part of the body’s immune arsenal after vac-
cination or infection, but Segev’s and Berenson’s stud-
ies did not evaluate them, because they are harder to
measure. T cells may provide some protection even in
people who lack detectable antibodies.
IMMUNE BOOST
reassuringly, people with some types of autoimmune
diseases have had fairly good responses to vaccina-
tion. Segev and his colleagues studied vaccinated peo-
ple with rheumatic and musculoskeletal diseases—
such as inflammatory arthritis or lupus—and found
that the vast majority of them produced COVID anti-
bodies after two doses of the mRNA vaccines.
Clinical neuroscientist Tjalf Ziemssen of University
Hospital Carl Gustav Carus in Dresden, Germany, and
his colleagues have been analyzing the response to
COVID vaccination in patients with multiple sclerosis,
a disease in which the immune system attacks the fatty
sheath that protects nerves in the brain and spinal cord.
It is often treated with immune-modulating drugs
called S1P receptor modulators and anti-CD20 mono-
clonal antibodies. In patients taking the latter, Ziems-
sen and his team found that the response among B cells
(which produce antibodies to COVID) was fairly low
but that there was a good response involving T cells
(which attack and kill viruses such as the COVID- caus-
ing SARS-CoV-2). Patients taking S1P receptor modu-
lators had a weaker response, but about two thirds still
developed a B or T cell response, or both.
Ziemssen does not recommend changing the dos-
ing of multiple sclerosis treatment to improve the vac-
cine response. Rather he suggests that patients getting
infusion treatments for the disease should wait a month
after an infusion to get vaccinated. In patients who had
a good B and T cell response, he recommends a booster
shot at six months. For those who did not have a good
response, he recommends a third dose given sooner.
Still, many people with other, rarer immune dis-
eases are left wondering whether they are protected
against COVID. Dinah S., who asked that her last name
not be given to maintain her privacy, has a rare condi-
tion called mucous membrane pemphigoid, which
causes blistering of the gums and other areas. She
takes mycophenolate mofetil, an immunosuppressant
drug often prescribed for organ transplant recipients,
and has taken the steroid prednisone in the past.
Dinah was part of Segev and his colleagues’ stud-
ies. She initially received two doses of the Pfizer vac-
cine, but an antibody test revealed she had no response.
She then got the one-dose Johnson & Johnson shot and
was still negative for antibodies. So Dinah next got
three Moderna doses, after which she finally achieved
a response similar to healthy people who have had two
doses. The entire process lasted six months. “My ordeal
has contributed to approval of boosters for everyone
but especially for immunocompromised people,” she
says. “Boosters work and are needed!”
Since the pandemic began, Dinah has remained
effectively locked down in a “bubble” of three people,
taking strict precautions to limit her infection risk.
Now that she has a measurable response to her vacci-
nations, she says she is finally able to relax a bit. “The
big excitement that the vaccine brings me is that I
might get to go into a grocery store for the first timesince before lockdown,” she says. “Fully masked, at a
quiet time of day and in a big airy store but still. The
bulk spice and tea aisle calls to me.”
Johns Hopkins’s Segev recommends a three-
pronged approach to improving the vaccine response
among people with weakened immune systems. First,
he recommends trying a third dose. If that does not
work, some patients may be able to temporarily reduce
the amount of immunosuppressive medication they
are taking (although only if their doctor deems this
safe) and get another dose. Finally, if vaccination fails,
Segev recommends giving patients monoclonal anti-
bodies as a form of passive immunity against COVID.
Monoclonals are currently authorized for use after
confirmed infection or exposure to COVID, but Segev
hopes the Food and Drug Administration will consider
allowing this option for prophylactic use.
Vaccination is not the only protective measure im -
munocompromised people can take. They can avoid
crowds or being indoors with unvaccinated individuals
or those with frequent exposure to other people. They
can wear a high-quality mask such as an N95 around
people they do not live with and increase ventilation by
opening windows and using air purifiers. They can have
others test themselves before interacting with them.
These precautions, though more onerous than a shot in
the arm, are effective when layered together. “The best
thing we can do for immunocompromised people,”
Segev says, “is for everybody else to get vaccinated, so
that we protect our vulnerable friends and neighbors.”FROM OUR ARCHIVES
The New Science of Autoimmune Disease. Special report; September 2021.
scientificamerican.com/magazine/sa“The best thing we can do for
immunocompromised people is for
everybody else to get vaccinated.”
—Dorry Segev Johns Hopkins University