Table 3.

Efficacy of vaccines in patients affected by myasthenia gravis*

Vaccine	Authors	Number of patients	Study design	Follow-up period	Results / Conclusions
Influenza	Zinman et al. 2009 [20]	513 hospitalised MG pts	Retrospective, self-matched, population-based study	42 weeks	Older pts had lower risk for exacerbation of MG in the immediate post-vaccination period, yet this was not statistically significant (p = 0.073)
Influenza	Hung Youl Seok et al. 2017 [22]	258 MG pts: 133 received influenza vaccination; 121 experienced a common cold or an influenza-like illness (ILI)	Retrospective multicentre survey	None	The vaccine does not confer protection from ILI: difference between 11/133 (8.3%) vaccinated pts with ILI and 14/125 (11.2%) of the unvaccinated pts with ILI was not significant
Influenza	Ellen Strijbos et al. 2019 [23]	47 anti-AchR AChR + MG pts: 29 with (IM +) and 18 without (IM-) immunosuppressive therapy; 47 healthy controls	Longitudinal prospective, placebo-controlled study	4 weeks	Post-vaccination seroprotection was similar between healthy controls, IM + and IM- and between thymectomised and non-thymectomised patients
Tetanus	Strijbos et al. 2017 [36]	65 MG/LEMS pts (verum group), 23 anti-AchR + MG pts (placebo group), 20 historical healthy controls	Longitudinal prospective, Placebo-controlled	4 weeks	MG pts treated with immunosuppressants had significantly lower pre- and post-vaccine titres compared to controls (p < 0.01; p < 0.01). Although 5 pts were non responders, all patients had protective pre- and post-vaccine titres. Tetanus revaccination is thus effective in MG/LEMS pts
Tetanus	Csuka et al. 2013 [38]	158 MG pts, 279 systemic lupus erythematosus (SLE) pts and 208 healthy control subjects	Case–control study	None	Tetanus-antitoxoid IgG titre decreased only in the elderly subjects in all 3 groups and was not associated with the presence of anti-AchR in MG pts (p = 0.112). Vaccine-induced immunity was comparable to that of the general population
Diphtheria	Csuka et al. 2013 [38]	158 MG patients, 279 systemic lupus erythematosus (SLE) patients and 208 healthy control subjects	Case–control study	None	Diphtheria-antitoxin IgG titre decreased significantly (p < 0.001) with age in all 3 groups and was not associated with the presence of anti-AchR in MG patients (p = 0.196). Vaccine-induced immunity was comparable to that of the general population
Staphylococcus pneumoniae (23 polysaccharidic antigen pneumococcal vaccine)	Nasca et al. 1990 [40]	25 MG pts (5 subgroups), 11 control pts, 17 healthy volunteers	Longitudinal prospective	28 ± 5 days	Post-immunization titres were not significantly different between MG and control patients. MG patients receiving prednisone and chronic plasmapheresis had higher pre-immunization titres than did other patient groups and had significantly higher postimmunization titres than other MG subgroups. Antibody rebound and overshoot phenomena after plasmapheresis is a possible explanation
SARS-CoV2 (Pfizer mRNA BNT162b2 and Moderna mRNA 1273 vaccines)	Plymate et al. [48]	1 MG pts	Case report	Immunogenicity tests 71 days after end of 1st cycle, 85 days after end of 2nd cycle	No detectable specific T- and B-cells vaccine immunogenicity tests after 1st cycle with BNT162b2; positive tests after 2nd cycle with M1273. Repeat vaccination might represent a strategy to increase vaccine efficacy
SARS-CoV2 (Pfizer mRNA BNT162b2 and Moderna mRNA 1273 vaccines)	Golding et al. [49]	1 MG pts	Case report	Immunogenicity tests 4 weeks after end of 1st cycle, 2 weeks after end of 2nd cycle	No detectable specific neutralising antibodies after 1st cycle with M1273; elevated titre after 2nd cycle with Pfizer BNT162b2 and temporary interruption of immunosuppressive therapy. Although revaccination might have played a role, transitory remodulation of immunosuppressive therapies may represent a strategy to increase vaccine efficacy

^*Articles regarding safety of vaccinations in MG patients, found in the online database “PubMed”, are listed and summarised here. For each one, vaccine type, authors, number of patients included, study design, follow-up period and results/conclusions are indicated. Complete references are available in the “Bibliography” section