1.INTRODUCTION
Since December 2019, COVID-19 infection caused by
severe acute respiratory syndrome
type 2 coronavirus (SARS-CoV-2)
has rapidly spread worldwide, posing significant challenges to public
health systems in various countries around the world. SARS-CoV-2 has
undergone multiple rounds of variation since the outbreak. As of March
31, 2023, it has caused more than 6.8 million deaths worldwide, and the
total medical costs and other economic setbacks caused by the prevention
and treatment of COVID-19 are unprecedented. In addition, long-term
chronic epidemics of the disease, as well as various anti-epidemic
measures have caused a large number of psychological and social problems
among the population, exacerbating social instability, particularly in
less developed countries[1].Presently, there are
few specific drugs against this highly contagious ribonucleic acid
virus, and widespread vaccination in the population is considered one of
the effective interventions to substantially reduce morbidity and
mortality and end the virus epidemic [2].As of 31
March 2022, more than 13 billion vaccine doses have been administered
all over the world(https://covid19.who.int.). Multiple large randomized
controlled trials and real-world studies have demonstrated the safety
and efficacy of COVID-19 vaccines in the general
population[3, 4]. However, the safety of COVID-19
vaccination for some patients with specific diseases, especially
autoimmune diseases, has not been confirmed. Because these patients
often have immune dysfunction and are immunocompromised by long-term use
of immunosuppressants, they tend to be excluded from vaccine RCTs trial
participant selection[5].
ANC is a large group of autoimmune diseases characterized by an
inappropriate immune response, in which the body mistakenly recognizes
the nervous system as an immune target[6], causing
neurological damage, which often progresses or repeatedly exacerbates,
resulting in disability or death. Common conditions include
multiple sclerosis (MS),
myasthenia gravis (MG),
Guillain-Barre syndrome
(GBS),
neuromyelitis optica spectrum
disorder (NMOSD) and
chronic inflammatory
demyelinating polyneuropathy (CIDP) , etc. Infection is the most common
cause of exacerbation in ANC[7],SARS-CoV-2 may
activate neuroinflammatory pathways[8], and severe
pneumonia rates and mortality are higher in ANC patients infected with
SARS-CoV-2[9].In addition,
immunosuppressive therapy (IST)
also increases the chance of severe pneumonia post-infection in ANC
patients. For these reasons, vaccination is necessary to protect these
patients from SARS-CoV-2 infection. Paradoxically, the vaccine itself
contains weakened or inactivated parts (antigens) of specific organisms
that can trigger immune responses and induce antigen production in the
body, and in general, this weakened version does not cause disease in
healthy people receiving the vaccine, but immune abnormalities and hypo
immunity are prevalent in people with autoimmune neurological diseases,
and the vaccine may elicit or aggravate autoimmune
diseases[10].Since the COVID-19 pandemic, multiple
studies have reported that vaccines induce autoimmune diseases or
exacerbate pre-existing conditions[11, 12],
however, more studies suggest that vaccination is safe for patients with
neuroimmune diseases[2, 13, 14]. These
contradictory conclusions fuelled the hesitancy of patients with
autoimmune diseases to vaccinate; Therefore, in the context of the
long-term epidemic of COVID-19, it is essential to clarify the risks and
benefits of post-inoculation for these patients.
Due to the lack of direct safety evidence for SARS-CoV-2 vaccination in
ANC patients, we conducted a systematic review and single-arm
meta-analysis based on various eligible safety studies in ANC patients
after vaccination to more fully assess the safety of SARS-CoV-2
vaccination in patients with autoimmune neurological diseases, eliminate
these patients’ hesitancy to vaccinate through evidence-based medicine,
and improve the protection rate of vulnerable populations.