This is a continuation of a series I’ve been helping to write for an education forum. This is the LONG version. For the short version, click here.
What is chickenpox? What is shingles?
Chickenpox (varicella) is a highly contagious illness caused by a virus known as varicella zoster virus. Cases tend to peak in winter and spring. You can also have chickenpox and develop immunity without ever developing symptoms. Generally speaking, chickenpox infection confers lifelong immunity. In children, chickenpox is generally very mild and only very rarely causes serious complications. However, in otherwise healthy adults, the complication rate is 15-25 times higher. Childhood chickenpox causes death in roughly 1 per 40,000 infections, so the risk of death from chickenpox in the U.S. is lower than the risk of death by lightning strike. However, the death rate from adulthood chickenpox infection is 20 times higher. In fact, even though children make up over 98% of chickenpox cases, adults make up almost half of chickenpox deaths [1-3]. Children with eczema are not at increased risk of complications .
After a chickenpox infection, the virus hibernates in a nerve. In times of stress and immune system dysfunction, the virus may reawaken and cause shingles. Shingles is associated with 4-5 times higher complication rate and medical costs than chickenpox .
In the U.S., the chickenpox vaccine is given at 12-15 months and again at 4-6 years . The shingles vaccine is recommended for people over the age of 60 .
In Canada, the chickenpox vaccine is given alone or with the MMR at 12 mo, 15 mo, 18 mo, and/or 4-6 years, depending on the province . The shingles vaccine is recommended for adults aged 50 and over .
How can I prevent chickenpox and shingles in my child?
A longstanding practice is to intentionally expose children to chickenpox because the infection is almost always harmless in children, but much more serious in adults. This practice is regarded as rarely harmful, but poses some risk of exposing immunocompromised people, with the exception that children with a planned exposure can have planned isolation during the potentially contagious period while children with an accidental exposure cannot. If you plan to intentionally infect your child, you should avoid immunocompromised people, pregnant women, and people with severe lung disease until you know for certain that your child is not contagious [1-2]. Also, if you choose to intentionally infect your child, be aware that mailing infectious material is highly illegal, in part because it is unknown how many people might be unknowingly exposed. Exposure is therefore best done in person.
It takes about 10-21 (usually 14-15) days after exposure to chickenpox before you develop the first spots; fever often occurs before the spots appear. The spots disappear within 7-10 days. Chickenpox is most contagious between 2 days before and 3 days after the start of the rash; but it is generally considered that children with chickenpox are contagious until at least 5 days after the onset of the rash or until all of the spots are dry and crusted. It is mainly contracted by direct contact with the spots, but it can be airborne as well. You can also catch chickenpox from direct contact with shingles lesions, but shingles is far less contagious. (You cannot catch shingles from shingles. But you can catch chickenpox from shingles. This is because the first time the virus causes an outbreak in you, it’s always chickenpox.)  To prevent chickenpox, avoid exposure to children with chickenpox, fever, or unidentified rash.
The chickenpox vaccine is a live virus vaccine, meaning the virus in the vaccine is capable of causing a chickenpox infection. There have been reported cases of people contracting the disease from a recently-vaccinated individual. For example, one pregnant woman contracted vaccine-strain chickenpox after her child was vaccinated . In another case, an adult woman received the vaccine and both she and her children shortly afterward developed vaccine-strain chickenpox . In yet another very alarming case, a woman who did not develop any symptoms, such as the characteristic rash, passed the vaccine-strain virus on to her newborn, who developed chickenpox . The shingles vaccine is also a live virus  and so can be presumed to shed as well. To prevent chickenpox, you should also avoid individuals who have recently received the chickenpox or shingles vaccines, as they should be considered just as contagious as someone who has an asymptomatic chickenpox infection.
However, ironically, the exact opposite should be done to prevent shingles. Regular exposure to chickenpox acts as a natural “booster shot” to protect adults against shingles [12-15]. In fact, working in childcare reduces your chances of developing shingles by 94% ! (That’s FAR more effective than the vaccine, as you’ll see later.) If you have been infected with the chickenpox virus in the past, then to prevent shingles, you should seek exposure to chickenpox.
How can I treat chickenpox and shingles in my child?
Even though exposure to chickenpox boosts immunity, and exposing a child with an active infection to people who are already immune would boost their immunity and benefit them by reducing their risk of shingles, it is considered unethical to intentionally expose someone without their knowledge. Thus, you should isolate your child during the contagious period, except to people who are aware of your child’s contagiousness and willing to expose themselves. You should also keep your child away from people who are at higher risk of complications, such as infants, pregnant women, and immunocompromised people.
Generally speaking, you can give anti-fever medicine if your child develops fever. However, research has shown that Tylenol is not effective for chickenpox . Other research has shown that anti-fever medicine degrades some of the immune response and makes the illness last longer, and so giving anti-fever medicine may be counterproductive [16, 17]. Do not give aspirin, which may cause a serious disorder called Reye’s syndrome in children with chickenpox. If you do give aspirin and your child develops vomiting, go to the emergency room, as this is a sign of Reye’s syndrome . In short, Tylenol doesn’t work, ibuprofen might be counter-productive, and aspirin might be dangerous. In other words, it’s probably best not to use anti-fever medicine unless the fever is over 106°F (41.1°C) .
Do not give Benadryl, including any creams that have Benadryl in them, because Benadryl toxicity has often been reported in children with chickenpox . Calamine lotion can give effective symptom relief, but make sure it doesn’t have Benadryl (diphenhydramine) in it. Daily baths with soap and water can also help destroy the virus and prevent bacterial infection .
Children with eczema are not at increased risk of complications. However, it’s important to note that a steroid cream should not be used during chickenpox, so if a child’s eczema is being treated with a steroid cream, you should stop using the cream while he has chickenpox .
An antiviral drug called acyclovir may shorten the length of the illness and reduce its severity, but does not reduce contagiousness. However, it does not reduce complications and has to be started no later than the first day of the rash because if it is started on or after the second day, it is ineffective . Acyclovir also does not reduce complications in adults .
The most common complication, occurring in 1-4% of chickenpox infections, is a bacterial infection of the spots . This should be prevented by keeping the spots clean, not breaking them open, and treating them with an anti-infective such as silver nitrate or certain essential oils. A brief fever before the spots appear is common. But if a second fever occurs several days after the spots appear, your child may have a serious bacterial infection and you should seek immediate medical attention .
Chickenpox may rarely cause pneumonia. You can prevent this by boosting your child’s immune system during the outbreak and having him breathe in an anti-infective such as certain essential oils. However, if your child develops difficulty breathing or starts looking sicker after he had started to get better (e.g., tired/lethargic, feverish, etc.), you should seek immediate medical attention .
How effective are the vaccines at preventing asymptomatic carriage?
Some studies have found that children who were vaccinated may develop shingles with the wild-type virus [19-20]. In other words, even though they never had symptomatic chickenpox, they apparently had an asymptomatic infection with the wild-type virus. This means vaccinated individuals can have asymptomatic infections with the wild-type virus in spite of having been vaccinated. Furthermore, as mentioned earlier, there has been at least one recorded case of an asymptomatic individual passing on vaccine-strain virus to her newborn child .
So, in short, vaccinated people can have asymptomatic infections with both the wild-type and the vaccine-strain virus, and can be contagious during that time. However, whether the vaccine affects the degree or duration of asymptomatic contagiousness has not to my knowledge been studied with the chickenpox vaccine. (Other studies have found that some vaccines increase or decrease, but do not eliminate, the length of asymptomatic carriage, as discussed in my previous posts on pertussis, meningococcal, HiB, and pneumococcal.)
Until proven otherwise, vaccinees should be considered at equal risk of asymptomatic carriage.
How effective are the chickenpox and shingles vaccines?
The chickenpox vaccine has highly disputed effectiveness. Because natural exposure to children with the infection boosts immunity, the vaccine is more effective when fewer children receive it [12-15, 21]. We also know, for example, that vaccinees can get both chickenpox [8-9] and shingles [19-20, 22] from the vaccine virus.
A Japanese study reported that 34.2% of chickenpox-vaccinated children developed symptomatic chickenpox within 7 years after vaccination. The study did not continue after 7 years, but it can presumably affect more children who are further away from the date of their vaccine. The study also did not look for evidence of asymptomatic infection. The authors concluded that the vaccine may reduce the severity of the symptoms but is not strong enough to prevent infection . A South Korean study found that chickenpox cases actually increased after the vaccine was introduced, and that symptoms were not milder in vaccinated children .
Since exposure to chickenpox boosts immunity and prevents shingles, researchers had long predicted that a decrease in chickenpox might cause an increase in shingles, estimating that it would result in an overall increased mortality rate (because shingles is more dangerous), with the increased disease and complications from shingles cancelling out any benefit from decreased chickenpox [12, 25-26]. In fact, this was the primary reason why nearly all European countries have chosen to forgo chickenpox vaccination. Some researchers even argued that it is unethical to vaccinate children against chickenpox, knowing that it will result in increased overall morbidity and mortality .
The researchers who predicted an increase in shingles were proven right when numerous studies in multiple countries using the chickenpox vaccine (including North America, Southeast Asia, and Australia) found that shingles cases increased and occurred in younger and younger ages, that cases of severe complications from shingles increased and occurred in ever younger ages, that chickenpox also occurred at younger and younger ages, and that chickenpox vaccination overall increased complications and medical costs—in other words, it was neither effective nor cost-effective [14-15, 21, 28-34].
Because the vaccines had very little effectiveness and also increased the incidence of shingles, it was necessary to add a booster shot  and later a shingles vaccine. The addition of these new vaccine doses is not cost-effective and is associated with a higher rate of complications than if vaccination had never been started .
According to CDC, the shingles vaccine lasts 5 years . However, the research is less than inspiring. The study conducted by the shingles vaccine manufacturer, Merck, found that it was at best 51% effective, but many of the patients were only followed for 31 days , so all we know for certain is that it might cut your risk in half for the first month after receiving it. Furthermore, they found it to be less than 40% effective for those aged 70 and older, while in people over 80 years old, the vaccine was only as effective as placebo—in other words, completely ineffective [11, 35]. It is also not effective at preventing postherpetic neuralgia (i.e., shingles pain) .
Are there other infectious diseases related to chickenpox and shingles vaccination?
After the MMR (measles-mumps-rubella) vaccine was introduced, cases of encephalitis (serious brain inflammation) due to measles, mumps, and rubella essentially disappeared. However, it was replaced with an even greater number of encephalitis cases by other bacteria and viruses that both had and had not been previously associated with encephalitis, including chickenpox encephalitis. Furthermore, these new cases of encephalitis occurred in younger age groups, which post more serious risks . In other words, MMR vaccination triggered more dangerous chickenpox infections, and one of the CDC’s cited reasons for chickenpox vaccination is the potential for severe complications like encephalitis . In most of Europe, it is still argued that because chickenpox is very mild in childhood and very severe in adulthood, and the increased shingles risk offsets any potential benefit, there is no justification for routine childhood chickenpox vaccination .
What are the risks of the vaccines?
Some research suggests that adverse events from varicella vaccination are at least equal to the adverse events of chickenpox infection that the vaccine prevented—in other words, there is no net change in adverse events between nearly 100% natural infection rate and nearly 100% vaccination rate .
In one study, systemic adverse reactions occurred in 11.9% of the vaccinated children . The manufacturer reports that the vaccine has caused some of the same serious side effects associated with the wild-type disease, such as pneumonitis . There is a combination MMR and chickenpox vaccine called ProQuad which is associated with higher fever and seizure rates compared to children who get MMR and chickenpox vaccination separately .
Shingles. Non-immunocompromised individuals can also develop vaccine-strain shingles as shortly as 2 years after vaccination [19-20, 22].
Indirect risks include the following:
Multiple Sclerosis. There is an increased risk of MS in people who contract measles, mumps, rubella, or chickenpox at a later age . Because the vaccines wear off and therefore put the individual at increased risk of infection at a later age, there is an indirectly increased risk of MS in children who receive the vaccine at a young age.
Heart Disease/Attacks. There is a decreased risk of heart disease such as coronary artery disease (CAD) and heart attacks in people who had chickenpox in childhood. Chickenpox reduces the risk of heart disease and heart attacks by 33% . Thus, indirectly, chickenpox vaccination may increase the risk of heart disease and heart attacks.
Brain Tumors. People who have had chickenpox in childhood have a lower risk of certain aggressive brain tumors called gliomas [42-44]. Thus, indirectly, chickenpox vaccination may increase the risk of brain tumors.
One study by the manufacturer of the shingles vaccine, Merck, reported a relatively high adverse reaction and severe adverse reaction rate following shingles vaccination. The complication rate was especially high in those over 80 years old [11, 35].
The shingles vaccine has been noted to cause severe autoimmune reactions, including a doubled risk of arthritis and a tripled risk of alopecia . The manufacturer study also found that people who received the shingles vaccine at the same time as the pneumonia vaccine had less of an immune response .
Another study of a newer shingles vaccine that is not currently available in the U.S. found that adverse reactions occurred in 84% of vaccine recipients within 7 days, and adverse reactions that were severe enough to prevent daily activities occurred in 17% of vaccinees .
What vaccines are offered against chickenpox and shingles?
(NOTE: These ingredients lists are not complete; they only list the most alarming ingredients.)
- ProQuad (U.S.). MMRV (measles-mumps-rubella-varicella) vaccine. Contains live measles, mumps, rubella, and varicella viruses. Ingredients include chick embryo, aborted human fetus lung cells (WI-38), aborted human fetus cells (MRC-5), cow serum, human albumin, monosodium L-glutamate (MSG), human albumin, and neomycin .
- Varivax (U.S.). Varicella-only vaccine. Contains live varicella virus. Ingredients include human embryonic cells, aborted human fetus lung cells (WI-38), guinea pig cells, DNA and protein from aborted human fetus cells (MRC-5), monosodium L-glutamate (MSG), EDTA, and neomycin .
- Varilrix (AU). Varicella-only vaccine. Contains live varicella virus. Ingredients include aborted human fetus cells (MRC-5), human albumin, lactose, cow products, and neomycin .
Shingles (Herpes Zoster)
- Zostavax (U.S.). Contains live varicella virus. Ingredients include porcine (pig) gelatin, monosodium L-glutamate (MSG), residual DNA and protein from MRC-5 (aborted human fetus) cells, neomycin, and calf serum .
So what’s the bottom line?
Chickenpox is very mild in childhood and has some long-term health benefits (e.g., decreased risk of multiple sclerosis, heart disease/heart attack, brain tumors), but poses much greater risk and fewer benefits in adulthood. Vaccination may merely delay chickenpox infection until adulthood, when it has considerably more risk. Natural chickenpox infection and repeated exposure to chickenpox decreases the risk of shingles. Conversely, chickenpox vaccination has very low effectiveness against chickenpox, increases the risk of shingles, and results in more severe shingles occurring at younger ages. Shingles is much more dangerous than chickenpox. The shingles vaccine does not appear to be very effective, but research is very limited; it is not effective in the oldest groups and is not yet approved for people under 50. Both vaccines are associated with some serious adverse effects, especially the shingles vaccine.