Monday, March 20, 2023

How Effective Is The Chickenpox Vaccine

Children Aged < 14 Years

Double dose of chicken pox vaccine found very effective

All children < 14 years of age are recommended to receive 1 dose of varicella-containing vaccine at 18 months of age. Children should receive this dose as MMRV vaccine. See Measles.

Children can receive varicella-containing vaccine from as young as 12 months of age. This can provide earlier protection against varicella, which may be appropriate in the context of travel or a varicella outbreak. This dose does not need to be repeated at 18 months of age, but there is no safety concern if the child still receives the dose scheduled at 18 months of age.

A 2nd dose of varicella-containing vaccine can provide extra protection

2 doses of varicella-containing vaccine provide more protection and minimise the chance of breakthrough varicella in children < 14 years of age .1 However, a 2nd dose of varicella-containing vaccine for children is not included on the National Immunisation Program schedule.

If parents or carers wish to minimise the risk of breakthrough varicella in children < 14 years of age, a 2nd dose of varicella-containing vaccine is recommended .

The minimum interval between doses of varicella-containing vaccine is 4 weeks.

Previous varicella infection is not a contraindication to varicella vaccine

Previous varicella infection is not a contraindication to varicella vaccination. Children who have had varicella infection can receive varicella-containing vaccines. See also Serological testing for varicella immunity from infection or vaccination.

Can A Vaccine Prevent Chickenpox

Yes, it is highly effective and recommended by the American Academy of Pediatrics and Advisory Committee on Immunization Practices . Varicella vaccine has reduced the numbers of chickenpox cases and their complications by 90%. The current aim in the U.S. and many other countries is to achieve universal immunization of children with the chickenpox vaccine . The vaccination requires only two shots, may be combined with MMR in one vaccine, and is very safe and effective. The first vaccination is given at 12 to 15 months of age, and the second is given at 4 to 6 years of age. Catch-up vaccination in those who missed it in early childhood can be given at any time until adulthood, as long as a total of two doses have been given at least one to two months apart.

If an older person has not had chickenpox, the vaccine may be given at any time, although those over 50 should receive the shingles vaccine. There have been very few vaccine side effects. All but those with a compromised immune system should have the vaccination.

Chickenpox Vaccine Less Effective Over Time

But Protection Overall Is Still High, Study Shows

Feb. 17, 2004 — The chickenpox vaccine becomes less protective over time, but it remains highly effective for preventing more serious forms of the virus, a new study shows.

Researchers followed a group of children who had and had not been immunized to assess the long-term effectiveness of the varicella virus, or chickenpox, vaccine. They found that while the vaccine remained highly protective during the eight-year observation period, protection was greatest for most children in the first year following immunization. The vaccine’s overall effectiveness in preventing disease was 97% in that first year compared with 84% during subsequent years.

The vaccine is typically given to children between the ages of 12 and 18 months. The researchers also found protection to be compromised during the first year following vaccination with varicella in children immunized prior to age 15 months, but the difference in effectiveness disappeared over time.

The findings are reported in the Feb. 17 issue of the Journal of the American Medical Association.

Read Also: How Many People Are Fully Vaccinated

What Should I Do About An Exposure To Varicella

If you have been in contact with someone with chickenpox or shingles, or if you have a rash-associated illness that might be chickenpox or shingles, discuss your situation with your healthcare provider. Blood tests may be done to see if you have become infected with the virus or have had the disease in the past. If you are pregnant and not immune and have been exposed to chickenpox or shingles, call your healthcare provider immediately. Your provider may choose to treat you with a medication called varicella-zoster immune globulin , but in order for this medication to be most helpful, it needs to be given as soon as possible after your exposure to varicella.

Chickenpox Vaccine Loses Effectiveness In Study

Italian politician who opposed mandatory vaccination gets ...
  • Read in app

BOSTON, March 14 The chickenpox vaccine Varivax has changed the profile of the disease in the population, researchers are reporting.

In a study appearing Thursday in The New England Journal of Medicine, the researchers confirm what doctors have already known that the vaccine has sharply reduced the number of cases in children but that its protection does not last long.

With fewer natural cases of the disease, the study says, unvaccinated children or those whose first dose of the vaccine fails to work are getting chickenpox later in life, when the risk of complications is higher.

If youre unvaccinated and you get it later in life, theres a 20-times greater risk of dying compared to a child, and a 10- to 15-times greater chance of getting hospitalized, said Dr. Jane Seward of the Centers for Disease Control and Prevention in Atlanta, who worked on the study.

Preliminary findings have already helped prompt the agencys Advisory Committee on Immunization Practices to recommend a booster shot at age 4 to 6, and also for older children, adolescents and adults.

No one knows how long the effects of a second shot would last, said the research team, led by Dr. Sandra Chaves of the C.D.C.

The United States has been vaccinating against chickenpox since 1995. But tests have shown that the vaccine is not very effective in 15 percent to 20 percent of children who receive only one dose.

Read Also: Does Humana Cover Shingrix Vaccine

When Should Adults Be Vaccinated Against Chickenpox

All adults who have never had chickenpox or received the vaccination should be vaccinated against it. Two doses of the vaccine should be given at least four weeks apart.

If you’ve never had chickenpox or been vaccinated and you are exposed to chickenpox, being vaccinated right away will greatly reduce your risk of getting sick. Studies have shown that vaccination within three days of exposure is 90% effective at preventing illness vaccination within five days of exposure is 70% effective. If you do get sick, the symptoms will be milder and shorter in duration.

This Vaccine Side Effects

Get emergency medical help if you have signs of an allergic reaction: dizziness, weakness, fast heartbeats hives difficult breathing swelling of your face, lips, tongue, or throat.

You should not receive a booster vaccine if you had a life-threatening allergic reaction after the first shot. Keep track of any and all side effects you have after receiving this vaccine. When you receive a booster dose, you will need to tell the doctor if the previous shot caused any side effects.

Becoming infected with chickenpox is much more dangerous to your health than receiving this vaccine. However, like any medicine, this vaccine can cause side effects but the risk of serious side effects is extremely low.

  • high fever

  • seizure

  • cough, pain or tight feeling in your chest, breathing problems or

  • easy bruising or bleeding, unusual weakness.

Common side effects include:

  • redness, itching, tenderness, swelling, bruising, or a lump where the shot was given

  • low fever or

  • mild skin rash that looks like chickenpox .

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report vaccine side effects to the US Department of Health and Human Services at 1-800-822-7967.

Also Check: Is The Flu Shot A Vaccine

Are Chickenpox And Shingles Serious Illnesses

The symptoms may be more severe in newborns, persons with weakened immune systems, and adults. Serious problems can occur and may include pneumonia , brain infection , and kidney problems. Many people are not aware that before a vaccine was available, approximately 10,600 persons were hospitalized, and 100 to 150 died, as a result of chickenpox in the U.S. every year.

Im Pregnant And Have Had A Blood Test For Chickenpox What Do The Results Of This Test Show

What Happened To Chickenpox?

The blood test can show that you:

  • Are immune and have no sign of recent infection. You have nothing further to be concerned about.
  • Are not immune and have not yet been infected. You should avoid anyone with chickenpox during your pregnancy.
  • Have or recently had an infection. You should discuss what the risks are for your stage of pregnancy with your healthcare provider.

Also Check: Who Vaccination Rates By Country

Why Do People Need A Chickenpox Vaccine

Most cases of chickenpox are relatively mild and run their course in five to 10 days. But it can be very serious, even life-threatening, in a small percentage of people. Before the varicella vaccine was licensed in the U.S. in 1995, there were approximately 100 deaths and more than 11,000 hospitalizations a year from chickenpox.

The risk of serious, life-threatening complications is greatest among infants, elderly adults, and people with weakened immune systems. But anyone can develop serious complications and there is no way to predict who will.

There’s another reason for getting a shot for chickenpox. The illness is highly contagious and without the vaccine, it can be spread by direct contact or through the air by sneezing or coughing. Also, someone can get it by coming in contact with fluid from chickenpox blisters. For that reason, children with chickenpox need to be kept out of school or day care for about a week or more until all blisters have dried and crusted over. The illness causes an itchy rash that usually forms between 200 and 500 blisters over the entire body, headaches, coughing, and fussiness. So even if the illness is mild, it still means five to 10 days of being uncomfortable.

Dose Route Of Administration And Schedule

Live attenuated zoster vaccine


Each dose is 0.65 mL .

Route of administration

Each dose is 0.5 mL .

Route of administration

Intramuscular, into the deltoid region of the upper arm.

Administration of the RZV as a subcutaneous injection is a vaccine administration error and should be avoided. However, if Shingrix is inadvertently administered subcutaneously, that dose will be considered as valid in the vaccine series. The second dose will be given as per vaccine schedule.

For more information, refer to Vaccine Administration Practices in Part 1.


2 doses, 2 to 6 months apart. A 0,12 months schedule may be considered for improved adherence to the 2nd dose .

Providers should consider different strategies to promote adherence to the two dose schedule for RZV .

Recommended Reading: How Do Most Vaccines Work

Making A Decision About Immunisation


One dose of the vaccine will protect around four out of five people from any kind of chickenpox and almost everyone from severe chickenpox.

Some people who have been vaccinated may still get chickenpox, but they will have a milder illness.

Vaccination provides long term but probably not lifelong immunity to chickenpox.

Risks associated with chickenpox
  • Every year in New Zealand about 60,000 people catch chickenpox. Several hundred people need hospital treatment, and one or two people either die or suffer from long-term disability as a result of chickenpox.
  • The severity and risk of complications is greater for adults. Complications can include severe skin infection, pneumonia and inflammation of the brain, kidney problems and sometimes death.
  • Pregnant women and their babies are at greater risk of harm from chickenpox. Chickenpox is also dangerous for people whose immune systems are weak, and people with liver or kidney problems.
  • The lesions may leave mild scarring in some skin types. Chickenpox can lead to shingles many decades after the initial disease.
Risks associated with the vaccine
Who shouldnt have the vaccine?

You shouldnt get immunised against chickenpox if you:

  • are pregnant
  • have a severe allergy to the vaccine or its ingredients, or an immune deficiency condition.

If you have further questions, talk to your doctor or practice nurse or call the Immunisation Advisory Centre free helpline 0800 IMMUNE .

When To Delay Or Avoid Chickenpox Immunization

12 Myths and Facts About Vaccines

The varicella vaccine is not recommended if your child:

Talk to your doctor about whether the vaccine is a good idea if your child:

  • is currently sick. Generally, simple colds and other minor illness should not stop your child from getting a vaccine.
  • takes aspirin. People who take aspirin should stop for 6 weeks before getting the chickenpox vaccine.
  • has gotten any other vaccines in the past month because some can affect how well the chickenpox vaccine will work
  • has ever had a low platelet count

Your doctor may decide that the benefits of vaccinating your child outweigh the potential risks.

Pregnant women should not get the chickenpox vaccine until after they give birth.

Also Check: Where Can I Get My Meningitis Vaccine

Simultaneous Administration With Other Vaccines

RZV and LZV may be administered concomitantly with other live vaccines given by the parenteral, oral, or intranasal routes. For concomitant parenteral injections, different injection sites and separate needles and syringes should be used.

In general, inactivated vaccines including RZV may be administered concomitantly with, or at any time before or after, other inactivated vaccines or live vaccines protecting against a different disease.

LZV may be given at any time before or after live oral or intranasal vaccines. If two live parenteral vaccines are not administered concomitantly, there should be a period of at least 4 weeks before the second live parenteral vaccine is given.

Concomitant administration of pneumococcal 23-valent polysaccharide vaccine and LZV has not resulted in decreased efficacy and so the two vaccines can be given concomitantly.

For more information, refer to Timing of Vaccine Administration in Part 1.

Children 12 Months Through 12 Years Old

  • 2 doses of varicella vaccine should be given subcutaneously, separated by at least 3 months.
  • MMRV vaccine is approved for healthy children in this age group.

Single-antigen vaccine and MMWR vaccine can be used for the routine 2-dose varicella vaccination.

  • First dose: age 12 through 15 months
  • Second dose: age 4 through 6 years

For the first dose, CDC recommends that MMR and varicella vaccines be given separately in children 12 through 47 months old unless the parent or caregiver expresses a preference for MMRV vaccine. For the second dose of measles, mumps, rubella, and varicella vaccines at any age and for the first dose at age 48 months, use of MMRV vaccine generally is preferred over separate injections of MMR and varicella vaccines.

Both vaccines may be given at the same time as other vaccines for children age 12 through 15 months and age 4 through 6 years.

Recommended Reading: How Many People In The United States Have Been Vaccinated

What Is The Prognosis Of Chickenpox

The prognosis of uncomplicated chickenpox is generally good when acquired in childhood, and even in most adults, after the chickenpox rash goes away. Most people never experience chickenpox symptoms again after the first occurrence, and they are immune to other people’s chickenpox. This is because the virus remains dormant in the nervous system this also means that chickenpox can sometimes resurface later in life as shingles .

Concerns About Side Effects

Chicken Pox Vaccine

If a side effect following immunisation is unexpected, persistent or severe, or if you are worried about yourself or your child’s condition after immunisation, see your doctor or immunisation nurse as soon as possible or go directly to a hospital. It is important to seek medical advice if you are unwell, as this may be due to other illness, rather than because of the immunisation. Immunisation side effects may be reported to the Victorian vaccine safety service, the central reporting service in Victoria on 1300 882 924, select option one. You can discuss with your immunisation provider how to report adverse events in other states or territories.

Also Check: Who Should Not Get Meningitis Vaccine

Uncommon Rare And Very Rare Adverse Events

Uncommon adverse events occur in 0.1% to less than 1% of vaccinees. Rare and very rare adverse events occur, respectively, in 0.01% to less than 0.1% and less than 0.01% of vaccinees.

Both HZ vaccines are safe with serious adverse events reported very rarely in immunocompetent individuals.

Recurrence or exacerbation of herpes zoster ophthalmicus following LZV vaccination has been reported very rarely, involving several cases world-wide following LZV immunization. Following a causality assessment of seven cases of HZO which were temporally associated with the administration of LZV, NACI concluded that there was insufficient evidence to recommend for or against the administration of LZV in individuals with a history of HZO. More evidence is required for further assessment of risk related to HZO recurrence in LZV recipients. At this time, there is insufficient evidence to assess the risk related to HZO recurrence following RZV recipients.

See Contraindications and Precautions if considering vaccinating a person with previous HZO.

For more information, refer to Vaccine safety in Part 2 and the product monograph in Health Canada’s Drug Product Database.

The Chickenpox Virus Has A Fascinating Evolutionary History That Continues To Affect Peoples’ Health Today

by Patricia L. Foster, The Conversation

In July 2021, a Centers for Disease Control and Prevention presentation obtained by the press noted that the delta variant of COVID-19 “is as transmissible as chickenpox.”

As some researchers have pointed out, the CDC’s comparison was an overstatement. Based on various studies and projections, on average a person infected with the delta strain of COVID-19 can infect six or seven people, whereas someone infected with chickenpox can infect nine or 10. Nonetheless, both diseases are highly contagious, although the viruses that cause them are very different.

While many diseases, such as Ebola and influenza, originate from viruses that made relatively recent “jumps” from animals to humans, other disease-causing pathogens have been with humans throughout evolution. The virus that causes chickenpox is one of these, coexisting with the human evolutionary line for millions of years.

I am a microbiologist interested in pathogens and the diseases they cause. Chickenpox is a childhood disease, and until a couple of decades ago, nearly all children in the United States got it. A vaccine campaign that began in the 1990s has made the disease rare in children in the U.S., but the virus lingers in the body and can reappear in unvaccinated adults years later as shingles. The virus’s ability to do this disappearing-and-reappearing trick may be the key to its long evolutionary history.

Chickenpox and shingles stem from the same virus

Explore further

Read Also: How Many People Have Been Vaccinated In Kentucky

Popular Articles
Related news