Adult chickenpox can be severe; vaccination provides up to 98% protection with full immunization schedule

Compared with children, chickenpox in adults often progresses more severely, with high fever, intense muscle pain, and a high risk of complications such as pneumonia, ARDS, encephalitis, or sepsis. Despite this, many people still treat it as a common skin condition, delaying care until the disease becomes critical.

Vaccination is an effective prevention measure, with protection up to 98% when the full immunization schedule is completed.

Severe adult cases highlight risks after delayed care

Doctors at the Intensive Care Center of the National Center for Tropical Diseases (Bệnh viện Bệnh Nhiệt đới Trung ương) have reported multiple cases of severe chickenpox complications requiring urgent intervention.

A typical case involved patient S.V.T., 39, from Lang Son. After undergoing bowel obstruction surgery at a local facility, chickenpox lesions began erupting on the abdomen immediately after the operation and rapidly spread across the body. The patient faced a difficult-to-control risk of intra-abdominal infection.

Laboratory results after admission showed CRP rising to 348 mg/L (more than 70 times the normal level), procalcitonin reaching 100 ng/mL, and white blood cell count dropping to 1.94 G/L—indicators consistent with severe immune suppression and widespread infection.

Dr. Nguyen Hong Ky, from the ICU at the hospital, said the case was particularly complex because postoperative complications and septicemia occurred simultaneously with a chickenpox-related infectious outbreak.

Another case involved patient L.V.T., 20, from Lao Cai, admitted late due to complacency about seeking early medical care. By the time of admission, the virus had invaded deep into internal organs, leading to respiratory failure and acute liver failure in the setting of severe nephrotic syndrome.

Pregnancy case and superinfection linked to lack of vaccination

Earlier, Viện Y học Nhiệt đới Bach Mai and Bệnh viện Bach Mai also treated a pregnant woman with chickenpox presenting with high fever and a widespread rash. Patient Q.H, 26, from Hanoi, was in her 18th week of pregnancy and worked as a kindergarten teacher with direct exposure to children with chickenpox.

After several days, she developed persistent fever (38.2°C), fatigue, headache, and vesicular rashes scattered on the face, chest, and back. Tests confirmed chickenpox with elevated inflammatory markers (CRP), spleen enlargement, and a rapid fetal heart rate of 177 bpm. She was admitted and treated with the antiviral drug Aciclovir, with close monitoring for both infection status and fetal well-being.

Doctors noted that a common feature across most severe cases is that patients had never received the varicella vaccine.

At the Cam Khê regional health center (Phú Thọ), clinicians have also recorded cases of varicella superinfection. The Department of General Internal and Infectious Diseases is treating patient D., 35, who had several days of high fever with chills, scattered blisters, and body weakness before admission. On arrival, the condition was more severe, with numerous crusted red lesions interspersed with blisters, along with itching and discomfort that affected daily activities.

Based on clinical assessment, doctors diagnosed extraneous varicella with superinfection—an uncommon complication that can occur when skin lesions are not properly cared for, allowing bacteria to invade.

How chickenpox spreads and when outbreaks peak

Doctors emphasized that chickenpox is an infectious disease spread mainly through respiratory transmission. The virus spreads via droplets when infected people talk, cough, or sneeze, then can persist in the air and infect healthy individuals. This transmission mechanism can drive rapid community outbreaks, with peak transmission typically occurring in warm, humid conditions from mid-March to May.

Impact and risk statistics for adults and pregnancy

Bạch Thị Chính, MD, PhD, Medical Director of the VNVC vaccination system, warned that chickenpox can lead to skin superinfections, pneumonia, encephalitis, and other serious outcomes—especially in adults, who face a much higher risk of severe progression than children, including acute respiratory failure, sepsis, liver inflammation, and encephalitis, and even death.

“Studies show that hospitalization rates for adults with chickenpox are about 13 times higher and mortality is about 25 times higher than in children. Pneumonia is the most common complication (5–15%), with mortality potentially reaching 30%. In pregnant women, the danger is even higher. About 20% of varicella cases can lead to pneumonia, with mortality up to 40%,” Dr. Chính said.

Prevention: vaccination, safe home care, and early medical attention

Doctors also highlighted that home care mistakes can break the skin’s protective barrier and allow bacteria to invade, potentially leading to sepsis and multi-organ failure. Examples include avoiding bathing or wind, applying leaves, self-medicating, or picking blisters.

From clinical practice, doctors advise the public not to ignore early signs such as fever, fatigue, or vesicular lesions. If symptoms are abnormal, patients should seek medical care promptly for timely diagnosis rather than relying on unverified home remedies. For pregnancy, proactive infection prevention before conception is essential, and if fever or rash develops during pregnancy, patients should seek medical care early for diagnosis and appropriate management.

Beyond vaccination, prevention measures include personal hygiene (handwashing with soap, using personal items, and cleaning and sanitizing living environments) and managing underlying conditions such as cardiovascular disease, diabetes, and asthma to reduce the risk of infection and complications. If infected, patients should be isolated and treated according to proper protocols to limit complications and transmission.

Vaccines available in Vietnam and timing for pregnancy

Currently, Vietnam has Varilrix (Belgium) for children from 9 months and adults, Varivax (USA) and Varicella (Korea) for children from 12 months and older and adults. Proquad (USA) covers measles, mumps, rubella in addition to varicella for children from 12 months and older and adults.

Pregnant women should be vaccinated against varicella before pregnancy at least 1–3 months prior, depending on the vaccine type.