Measles Virus

Classification

General Characteristics

• Genus: Morbillivirus
• Family: Paramyxoviridae Paramyxoviridae A family of spherical viruses, of the order mononegavirales, somewhat larger than the orthomyxoviruses, and containing single-stranded RNA. Subfamilies include paramyxoviridae and pneumovirinae. Respiratory Syncytial Virus
• Single-stranded, linear, negative-sense RNA Negative-sense RNA RNA viruses that have their genetic material encoded in the form of single-stranded, negative-sense RNA. Unlike retroviruses they do not employ DNA intermediates in their life-cycle. Respiratory Syncytial Virus virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
• Enveloped virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
• Large helical Helical Computed tomography where there is continuous x-ray exposure to the patient while being transported in a spiral or helical pattern through the beam of irradiation. This provides improved three-dimensional contrast and spatial resolution compared to conventional computed tomography, where data is obtained and computed from individual sequential exposures. Computed Tomography (CT) capsid Capsid The outer protein protective shell of a virus, which protects the viral nucleic acid. Capsids are composed of repeating units (capsomers or capsomeres) of capsid proteins which when assembled together form either an icosahedral or helical shape. Virology carries RNA-dependent RNA polymerase RNA-dependent RNA polymerase An enzyme that catalyses rna-template-directed extension of the 3′- end of an RNA strand by one nucleotide at a time, and can initiate a chain de novo. Virology in virion.

Epidemiology and Pathogenesis

Epidemiology

• Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: 50–300/year in the United States
• Mainly a childhood disorder
• Since 2-dose measles, mumps Mumps Mumps is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. Mumps is typically a disease of childhood, which manifests initially with fever, muscle pain, headache, poor appetite, and a general feeling of malaise, and is classically followed by parotitis. Mumps Virus/Mumps, rubella Rubella An acute infectious disease caused by the rubella virus. The virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system. Rubella Virus ( MMR MMR A DNA repair pathway involved in correction of errors introduced during DNA replication when an incorrect base, which cannot form hydrogen bonds with the corresponding base in the parent strand, is incorporated into the daughter strand. Excinucleases recognize the base pair mismatch and cause a segment of polynucleotide chain to be excised from the daughter strand, thereby removing the mismatched base. Lynch syndrome) vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination, US cases ↓ 99%
• Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: males = females
• Higher mortality Mortality All deaths reported in a given population. Measures of Health Status observed in women at all ages
• Fatality rate 4%–10% in developing countries

Transmission

• Highly contagious → 90% secondary infection rate: CDC–reportable disease
• Humans are the only known reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli.
• Vectors:
  • Respiratory droplets Droplets Varicella-Zoster Virus/Chickenpox
  • Person-to-person contact
  • Fomites Fomites Inanimate objects that carry pathogenic microorganisms and thus can serve as the source of infection. Microorganisms typically survive on fomites for minutes or hours. Common fomites include clothing, tissue paper, hairbrushes, and cooking and eating utensils. Adenovirus
• Young children and pregnant women are particularly susceptible to infection.

Clinically relevant species

• Paramyxoviridae Paramyxoviridae A family of spherical viruses, of the order mononegavirales, somewhat larger than the orthomyxoviruses, and containing single-stranded RNA. Subfamilies include paramyxoviridae and pneumovirinae. Respiratory Syncytial Virus family:
  • Paramyxovirus Paramyxovirus Mumps Virus/Mumps: includes parainfluenza viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology and mumps Mumps Mumps is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. Mumps is typically a disease of childhood, which manifests initially with fever, muscle pain, headache, poor appetite, and a general feeling of malaise, and is classically followed by parotitis. Mumps Virus/Mumps virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
  • Pneumovirus Pneumovirus A genus of the family paramyxoviridae (subfamily pneumovirinae) where the human and bovine virions have neither hemagglutinin nor neuraminidase activity. Respiratory syncytial virus, human is the type species. Respiratory Syncytial Virus: includes respiratory syncytial virus Respiratory Syncytial Virus Respiratory syncytial virus (RSV) is an enveloped, single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae and the genus Orthopneumovirus. Two subtypes (A and B) are present in outbreaks, but type A causes more severe disease. Respiratory syncytial virus causes infections of the lungs and respiratory tract. Respiratory Syncytial Virus
  • Morbillivirus: includes measles virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology
• Paramyxoviridae Paramyxoviridae A family of spherical viruses, of the order mononegavirales, somewhat larger than the orthomyxoviruses, and containing single-stranded RNA. Subfamilies include paramyxoviridae and pneumovirinae. Respiratory Syncytial Virus family causes 30%–40% of all acute respiratory infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease in infants and children.

Pathophysiology

• Incubation Incubation The amount time between exposure to an infectious agent and becoming symptomatic. Rabies Virus period: 2–3 weeks
• Virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology enters via upper respiratory tract → infects local lymphatic tissues → amplification in regional lymph nodes Lymph Nodes They are oval or bean shaped bodies (1 – 30 mm in diameter) located along the lymphatic system. Lymphatic Drainage System: Anatomy → dissemination to various organs ( testes Testes Gonadal Hormones, ovaries Ovaries Ovaries are the paired gonads of the female reproductive system that contain haploid gametes known as oocytes. The ovaries are located intraperitoneally in the pelvis, just posterior to the broad ligament, and are connected to the pelvic sidewall and to the uterus by ligaments. These organs function to secrete hormones (estrogen and progesterone) and to produce the female germ cells (oocytes). Ovaries: Anatomy, thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy gland, pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas: Anatomy, and central nervous system Central nervous system The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges. Nervous System: Anatomy, Structure, and Classification)
• 2 envelope Envelope Bilayer lipid membrane acquired by viral particles during viral morphogenesis. Although the lipids of the viral envelope are host derived, various virus-encoded integral membrane proteins, i.e. Viral envelope proteins are incorporated there. Virology glycoproteins Glycoproteins Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins. Basics of Carbohydrates bind BIND Hyperbilirubinemia of the Newborn to host cells: 
  • Hemagglutinin (H)
  • Fusion protein (F)
• Negative-sense strand ssRNA (single-stranded RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure) used as template strand for positive strand
• ssRNA translated by host ribosomes Ribosomes Multicomponent ribonucleoprotein structures found in the cytoplasm of all cells, and in mitochondria, and plastids. They function in protein biosynthesis via genetic translation. The Cell: Organelles → produces proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis
• Viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology are packaged while host cells undergo lysis.
• Generalized immunosuppression: 
  • Suppression Suppression Defense Mechanisms of interferon production through nonstructural proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis V and C
  • ↓ In delayed-type hypersensitivity Delayed-type hypersensitivity Type IV hypersensitivity reaction, or delayed-type hypersensitivity, is a cell-mediated response to antigen exposure. The reaction involves T cells, not antibodies, and develops over several days. Presensitized T cells initiate the immune defense, leading to tissue damage. Type IV Hypersensitivity Reaction
  • ↓ Interleukin (IL)-12 production
  • ↓ Antigen-specific lymphoproliferative responses

Clinical Presentation

Clinical presentation

• Prodromal stage:
  • Cough
  • Coryza Coryza Inflammation of the nasal mucosa, the mucous membrane lining the nasal cavities. Rhinitis
  • Conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis
  • Photophobia Photophobia Abnormal sensitivity to light. This may occur as a manifestation of eye diseases; migraine; subarachnoid hemorrhage; meningitis; and other disorders. Photophobia may also occur in association with depression and other mental disorders. Migraine Headache
  • High fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
• Day 3: Koplik’s spots (bluish-gray grain of salt with red halo, 1–2 days)
• Day 4: maculopapular Maculopapular Dermatologic Examination rash Rash Rocky Mountain Spotted Fever (from head/ neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess → body)

Complications

At least 1 complication occurs in 30% of cases:

• Immune suppression Suppression Defense Mechanisms and secondary infection:
  • Secondary infection can be with viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology or bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology.
  • Tuberculosis Tuberculosis Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis complex bacteria. The bacteria usually attack the lungs but can also damage other parts of the body. Approximately 30% of people around the world are infected with this pathogen, with the majority harboring a latent infection. Tuberculosis spreads through the air when a person with active pulmonary infection coughs or sneezes. Tuberculosis reactivation Reactivation Herpes Simplex Virus 1 and 2 has been described.
• Diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea:
  • Most common
  • Seen in 8% of cases
• Pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia:
  • Most deadly complication
  • Seen in 6% of cases
• Otitis media
• Giant cell pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia: 
  • Seen in individuals with cellular immunity Cellular immunity Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role. Squamous Cell Carcinoma (SCC) deficiencies (e.g., leukemia, AIDS AIDS Chronic HIV infection and depletion of CD4 cells eventually results in acquired immunodeficiency syndrome (AIDS), which can be diagnosed by the presence of certain opportunistic diseases called AIDS-defining conditions. These conditions include a wide spectrum of bacterial, viral, fungal, and parasitic infections as well as several malignancies and generalized conditions. HIV Infection and AIDS)
  • Often fatal
• Acute disseminated encephalomyelitis Acute disseminated encephalomyelitis Acute disseminated encephalomyelitis (ADEM) is an immune-mediated, inflammatory, monophasic, demyelinating condition that affects the white matter of the brain and spinal cord. As a rapidly progressive post-infectious encephalomyelitis, ADEM is characterized by demyelination in the brain and spinal cord. Acute Disseminated Encephalomyelitis (ADEM) ( ADEM ADEM Acute disseminated encephalomyelitis (ADEM) is an immune-mediated, inflammatory, monophasic, demyelinating condition that affects the white matter of the brain and spinal cord. As a rapidly progressive post-infectious encephalomyelitis, ADEM is characterized by demyelination in the brain and spinal cord. Acute Disseminated Encephalomyelitis (ADEM)):
  • Postinfectious inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of central nervous system Central nervous system The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges. Nervous System: Anatomy, Structure, and Classification
  • Symptoms include weakness, fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia, and blindness Blindness The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of eye diseases; optic nerve diseases; optic chiasm diseases; or brain diseases affecting the visual pathways or occipital lobe. Retinopathy of Prematurity.
• Subacute sclerosing panencephalitis:
  • Fatal degenerative disease of CNS
  • Occurs 7–10 years after infection
  • Poorly understood
• Blindness Blindness The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of eye diseases; optic nerve diseases; optic chiasm diseases; or brain diseases affecting the visual pathways or occipital lobe. Retinopathy of Prematurity: due to keratitis Keratitis Inflammation of the cornea. Herpes Simplex Virus 1 and 2 and corneal ulceration Ulceration Corneal Abrasions, Erosion, and Ulcers

Diagnosis

The disease is diagnosed on clinical suspicion followed by confirmatory laboratory testing. Suspected cases should be isolated until confirmed.

• History reveals trio of symptoms: cough, coryza Coryza Inflammation of the nasal mucosa, the mucous membrane lining the nasal cavities. Rhinitis, conjunctivitis Conjunctivitis Conjunctivitis is a common inflammation of the bulbar and/or palpebral conjunctiva. It can be classified into infectious (mostly viral) and noninfectious conjunctivitis, which includes allergic causes. Patients commonly present with red eyes, increased tearing, burning, foreign body sensation, and photophobia. Conjunctivitis
• Exam confirms maculopapular Maculopapular Dermatologic Examination rash Rash Rocky Mountain Spotted Fever.
• Diagnosis made by 1 of 3:
  • Hemagglutination inhibition:
    • Rapid ↑ in IgG IgG The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b. Hypersensitivity Pneumonitis titers
    • Positive IgM IgM A class of immunoglobulin bearing mu chains (immunoglobulin mu-chains). Igm can fix complement. The name comes from its high molecular weight and originally being called a macroglobulin. Immunoglobulins: Types and Functions
  • RT-PCR RT-PCR A variation of the pcr technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard pcr protocols. Polymerase Chain Reaction (PCR) with detection of measles RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure
• Consider lumbar puncture Lumbar Puncture Febrile Infant if concern for encephalitis Encephalitis Encephalitis is inflammation of the brain parenchyma caused by an infection, usually viral. Encephalitis may present with mild symptoms such as headache, fever, fatigue, and muscle and joint pain or with severe symptoms such as seizures, altered consciousness, and paralysis. Encephalitis.
• Consider chest X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage and concern for pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia.

Management

Management

• Supportive care:
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever reduction
  • Rehydration Rehydration Dengue Virus
  • Superinfection prevention measures
• High-dose vitamin A Vitamin A Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies:
  • In patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with known nutritional deficiencies
  • 2-dose IM injection has been shown to ↓ morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status and mortality Mortality All deaths reported in a given population. Measures of Health Status in children < 5 years of age
• Ribavirin Ribavirin A nucleoside antimetabolite antiviral agent that blocks nucleic acid synthesis and is used against both RNA and DNA viruses. Antivirals for Hepatitis C:
  • Used in cases of pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia
  • Reduces duration of symptoms and hospitalization Hospitalization The confinement of a patient in a hospital. Delirium
  • Reduces morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status and mortality Mortality All deaths reported in a given population. Measures of Health Status
• Vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination counselling

Prevention

• MMR MMR A DNA repair pathway involved in correction of errors introduced during DNA replication when an incorrect base, which cannot form hydrogen bonds with the corresponding base in the parent strand, is incorporated into the daughter strand. Excinucleases recognize the base pair mismatch and cause a segment of polynucleotide chain to be excised from the daughter strand, thereby removing the mismatched base. Lynch syndrome triple vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination:
  • Children should get 2 doses.
  • 1st dose at 12–15 months and 2nd at 4–6 years
  • Can be given to all ages
• MMRV vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination (measles, mumps Mumps Mumps is caused by a single-stranded, linear, negative-sense RNA virus of the family Paramyxoviridae. Mumps is typically a disease of childhood, which manifests initially with fever, muscle pain, headache, poor appetite, and a general feeling of malaise, and is classically followed by parotitis. Mumps Virus/Mumps, rubella Rubella An acute infectious disease caused by the rubella virus. The virus enters the respiratory tract via airborne droplet and spreads to the lymphatic system. Rubella Virus, and varicella):
  • Children up to age 12 should get 2 doses.
  • Only approved for children who are 12 months to 12 years of age
  • 1st dose at 12–15 months and 2nd dose at 4–6 years
• Infection gives lifelong immunity.

Comparison of Common Childhood Rashes