Table 2.

Description of articles reporting observational clinical trials that provided data on at least one outcome by sex.

Citation	Objective	Primary Outcome	Quotes	Statistically Significant Difference?
McMahon et al., 2021 [33]	Cutaneous reactions to vaccine	Adverse events	“Ninety per cent of the vaccine reactions were reported in female patients.”	Yes
Greinacher et al., 2021 [34]	Thrombotic thrombocytopenia after vaccination	Adverse events	“Among these patients, the median age was 36 years (range, 22–49); 9 of 11 were women. All the patients presented with concomitant thrombocytopenia (median nadir of platelet count, approximately 20,000 per cubic millimetre; range, 9000–107,000).”	Yes
Salmerón Ríos et al., 2021 [35]	Vaccine efficacy in frail or disabled nursing home residents	Effectiveness	“Frailty, disability, older age, sex, cognitive impairment, and comorbidities were not associated with different antibody titres.”	No
Boyarsky et al., 2021 [36]	Immunogenicity in solid organ transplant patients	Effectiveness	“The immune response to the vaccine by sex was found to have a p value = 0.60 and therefore sex is not statistically significant.”	No
Shimabukuro, 2021 [37]	Allergic reactions after the Moderna vaccine (December–January)	Adverse events	“The clinical and epidemiological characteristics of anaphylaxis case reports after receipt of the Moderna COVID-19 vaccine are similar to those reported after receipt of the Pfizer-BioNTech COVID-19 vaccine (5). […] A strong female predominance of anaphylaxis case reports exists for both vaccines.”	Yes
Lacson et al., 2021 [38]	Immunogenicity in patients undergoing dialysis	Effectiveness	“Factors associated with poor seroconversion in our cohort include female sex, younger vintage, potential immunosuppression from diseases, transplant, or medications, [Congestive Heart Failure], and covaccination and hospitalization during the peri-vaccination period.”	Yes
Shimabukuro, 2021 [39]	Allergic reactions after the Pfizer-BioNTech vaccine (December only)	Adverse events	“A strong female predominance of anaphylaxis case reports exists for both vaccines.”	Yes
Ou et al., 2021 [40]	Immunogenicity in solid organ transplant patients	Adverse events	“Females were more likely to experience systemic symptoms after either dose.”	Yes
Street et al., 2021 [41]	Efficacy in patients with chronic lymphocytic leukaemia	Effectiveness	“In a univariate analysis (this table), the variables found to be significantly associated with response included: younger age (≤65 years), female sex, early disease stage (Binet stage A), mutated IGHV, b2-microglobulin (≤3.5 mg/L), untreated/off-therapy ≤ 12 months from the last anti-CD20 therapy, IgG levels ≤ 550 mg/dL, IgM levels ≤ 40 mg/dL, and IgA levels ≤ 80 mg/dL.”	Yes
Padoan et al., 2021 [25]	Antibody response in a cohort of characterized healthcare workers	Effectiveness	“No significant anti-S-RBD level differences were found between males and females in any of the studied conditions.”	No

CD20: B-lymphocyte antigen CD20; IGHV: immunoglobulin heavy chain variable region genes; IgA: immunoglobulin A; IgG: immunoglobulin G; IgM: immunoglobulin M; S-RBD: anti-spike protein receptor-binding domain.