Varicella

Highly contagious disease due to varicella-zoster virus

Spread by direct contact or the respiratory route

Characteristic pruritic vesicular rash with fever

Complications include pneumonia, encephalitis, and cellulitis

Varicella Epidemiology

Children» 3.5 to 4 million cases each year» generally mild disease with rare

complications Adults

» 5% of all cases occur in those > 15 years» complications much more common

Varicella Vaccine

Varivax licensed April, 1995 A live, attenuated viral vaccine Contraindicated in these situations:

– immunosuppression– pregnancy– receipt of blood products—dose dependent– active untreated TB

Evidence of Varicella Immunity

Born in United States before 1980 Physician documented clinical history of

chicken pox or zoster Laboratory evidence of immunity Two doses of varicella vaccine after first

birthday separated by at least 4 weeks

Evidence of Varicella Immunity for Healthcare Worker

Physician documented clinical history of chicken pox or zoster

Laboratory evidence of immunity Two doses of varicella vaccine after first

birthday separated by at least 4 weeks

Varicella Vaccine Indications

All infants at age 12 months with second dose prior to entering school

– Minimum 3 month interval between doses Second dose recommended for anyone who has received

only one dose Children entering child care facilities or elementary schools

(or evidence of immunity) Assume immune if born in US before 1980 unless healthcare

worker, pregnant woman or immunocompromised

Varicella Vaccine Indications

Routine immunization of all adolescents and adults without evidence of immunity

Prenatal assessment + postpartum immunization

Varicella Vaccine Adverse Effects

Fever Rash

– At injection site: median number of lesions=2– Generalized: median number of lesions=5

Post-Vaccination Herpes Zoster

VAERS rate after vaccination 2.6/100,000 doses distributed

Rate after natural infection for healthy children <20 years 68/100,000 person years

Compare rates with caution– shorter vaccine follow up time– vaccine cases not always caused by vaccine virus

Rotavirus Vaccine

Rotavirus Infection

Half million childhood deaths worldwide

One third of hospitalizations for diarrhea

Incidence similar in developing and developed countries

Impact of Rotavirus in US

MMWR 2006; 55(RR-12)

Rotavirus Vaccines

Live oral vaccine stored refrigerated Two preparations

– Rotateq (Merck) Pentavalent bovine reassortment viruses Three oral doses

– Rotarix (GSK) Attenuated human rotavirus Two oral doses

Recommended at 2, 4, and (6 if Merck product used) months

Vaccine Schedule

First dose between 6 and 14 weeks of age– If inadvertently started, complete series

Second and third doses spaced by 4 to 10 weeks Series must be completed by 8 months of age Initiate or complete series for infants who have

had rotavirus infection

RV and Intussusception

No evidence that risk is different between vaccines

About 45-213 cases per birth cohort Prevents 53,000 hospitalizations and

170,000 ED visits per birth cohort

Vaccine Impact

Dramatic reductions in disease Decreased hospitalization by 42-63% Decreased lost workdays by 87%