Objectives:
Despite the universal use of the two-dose trivalent measles-mumps-rubella (MMR) vaccine in the past two decades, outbreaks of these diseases still occur in countries with high vaccine uptake, giving rise to concerns about primary and secondary failure of MMR vaccine components. Therefore, this review article has been conducted.

What is the seroconversion and waning rate estimates for the measles, mumps and rubella components of MMR vaccines?

Study design:
This review article included 62 studies.

Objectives:
Are comorbidities, like hypertension, diabetes, cardiovascular diseases, chronic obstructive pulmonary disease, chronic kidney disease and cancer associated with poor prognosis in COVID-19 patients?

Study design:
This review article included a total of 124 studies.

Objectives:
Do clinical symptoms, laboratory findings, radiographic signs and outcomes differ between COVID‐19 and influenza?

Study design:
This review article included 157 studies with 75,164 COVID-19 patients, 251 studies with 113,818 influenza type A patients and 47 studies with 9,266 influenza type B patients.

Objectives:
There are numerous trials reported the effect of alpha-lipoic acid (ALA) on obesity measurements; while no summarised dose-response meta-analysis is available to address the effects of dose and duration of ALA supplementation on obesity measurements. Therefore, this review article has been conducted.

Objectives:
Is the mortality rate related to the COVID-19 pandemic higher in European males than in European females?

Study design:
This review article included information from 23 European countries that reported separately by gender mortality rates related to COVID-19. The sample comprised 484,919 men and 605,229 women positive for COVID-19.

Results and conclusions:   

Objectives:
Malnutrition underlies 45% of under-5 deaths globally. Severe acute malnutrition (SAM) is the most serious form of undernutrition, characterized by wasting with or without edema. Mortality remains high (10%-40%) among children requiring hospitalization for complicated SAM. Therefore, this review article has been conducted.

Objectives:
What is the diagnostic accuracy of serologic methods for COVID-19 based on assay design and post-symptom?

Study design:
This review article included 4 cohort, 16 case-control and 7 longitudinal studies with a total of 4,565 participants.

Results and conclusions:   
The investigators found the pooled sensitivity of IgG, IgM and TAB in RNA-positive COVID-19 cases was 0.76 [95% CI = 0.65 to 0.86], 0.69 [95% CI = 0.59 to 0.78] and 0.78 [95% CI = 0.70 to 0.85], respectively.

Objectives:
COVID-19 has become a global epidemic and effective therapies have not been discovered up to now. Therefore, this review article has been conducted.

Does tocilizumab have potential effectiveness to treat COVID?

Study design:
This review article included 13 retrospective case-control studies (n = 2,285 patients) and 6 retrospective single-armed studies (n = 208 patients).

Objectives:
The prevalence and clinical outcomes of COVID-19 in patients with autoimmune diseases who are frequently treated with disease modifying therapies remains poorly understood. Therefore, this review article has been conducted.

Do patients with autoimmune diseases have an increased risk of COVID-19?

Study design:
This review article included 62 observational studies with a total of 319 ,025 patients with autoimmune diseases.

There was no publication bias.

Objectives:
Since licensure in 2006, rotavirus vaccines have been introduced in more than 100 countries. However, the efficacy of rotavirus vaccines is variable in settings with different child mortality levels. Therefore, this review article has been conducted.