For higher age groups the benefit to risk ratio increased.Also on 7 April 2021, an interim statement from the WHO said its advisory body, GACVS, found any "causal relationship" between the rare blood clot cases and AZD1222 to be "plausible but is not confirmed".On 20 April 2021, the safety committee of the EMA (PRAC) found a "possible link to very rare cases of unusual blood clots with low blood platelets" for the Johnson & Johnson Janssen vaccine; and required that these rare events, similar to those noted for AZD1222, should be listed as a very rare side effect. The EMA states the overall risk-benefit for the Janssen vaccine remains positive.On 16 December 2021, the US Centers for Disease Control and Prevention (CDC) recommended the Moderna and Pfizer­­-BioNTech vaccines should be preferred over the Janssen vaccine, following growing concerns about rare blood clots. Janssen should still be offered to people who specifically request it. History
Organizations
Global vaccine safety comes under the remit of the World Health Organization (WHO), and in particular its Global Advisory Committee on Vaccine Safety (GAVCS). Other drug regulatory agencies significantly involved include:
European Medicines Agency (EMA), the regional regulatory authority for the EU. Medicines and Healthcare products Regulatory Agency (MHRA), the medical authority for the United Kingdom. Paul Ehrlich Institute (PEI), a German federal agency supervised by the Federal Ministry of Health with expertise in vaccines and biomedicines. It is a WHO collaborating centre.
Psychiatric
Nausea may be caused by depression, anxiety disorders and eating disorders. Potentially serious
While most causes of nausea are not serious, some serious conditions are associated with nausea. These include pancreatitis, small bowel obstruction, appendicitis, cholecystitis, hepatitis, Addisonian crisis, diabetic ketoacidosis, increased intracranial pressure, spontaneous intracranial hypotension, brain tumors, meningitis, heart attack, rabies carbon monoxide poisoning  and many others. Comprehensive list
Inside the abdomen
Obstructing disorders

Gastric outlet obstruction
Small bowel obstruction
Colonic obstruction
Superior mesenteric artery syndromeEnteric infections

Viral infection
Bacterial infectionInflammatory diseases

Celiac disease
Cholecystitis
Pancreatitis
Appendicitis
HepatitisSensorimotor dysfunction

Gastroparesis
Intestinal pseudo-obstruction
Gastroesophageal reflux disease
Irritable bowel syndrome
Cyclic vomiting syndromeOther

Non-celiac gluten sensitivity
Biliary colic
Kidney stone
Cirrhosis
Abdominal irradiation

Outside the abdomen
Cardiopulmonary

Cardiomyopathy
Myocardial infarction (heart attack)
Paroxysmal coughInner-ear diseases

Motion sickness
Labyrinthitis
MalignancyIntracerebral disorders

Malignancy
Hemorrhage
Abscess
Hydrocephalus
Meningitis
Encephalitis
RabiesPsychiatric illnesses

Anorexia and bulimia nervosa
DepressionOther

Post-operative vomiting
Nociception

Medications and metabolic disorders
Drugs

Chemotherapy
Antibiotics
Antiarrhythmics
Digoxin
Oral hypoglycemic medications
Oral contraceptivesEndocrine/metabolic disease

Pregnancy
Uremia
Ketoacidosis
Thyroid and parathyroid disease
Adrenal insufficiencyToxins

Liver failure
Alcohol

Pathophysiology
Research on nausea and vomiting has relied on using animal models to mimic the anatomy and neuropharmacologic features of the human body. The physiologic mechanism of nausea is a complex process that has yet to be fully elucidated. There are four general pathways that are activated by specific triggers in the human body that go on to create the sensation of nausea and vomiting. Central nervous system (CNS): Stimuli can affect areas of the CNS including the cerebral cortex and the limbic system. These areas are activated by elevated intracranial pressure, irritation of the meninges (i.e. blood or infection), and extreme emotional triggers such as anxiety. The supratentorial region is also responsible for the sensation of nausea. Chemoreceptor trigger zone (CTZ): The CTZ is located in the area postrema in the floor of the fourth ventricle within the brain.