Dr. Greene’s Answer:
When deciding upon any immunization, it is wise to consider both the risks versus benefits of the vaccine and the risks versus benefits of not receiving the vaccine. Children who do not get the vaccine are likely to develop chickenpox. This common viral infection is usually mild and not life-threatening. Although these children may be miserable for several days, and miss a week of school or day-care (stranding parents at home), they will likely recover from the 250-500 itchy blisters with nothing more to show for it than a few small scars. Each year, however, about 200,000 of the millions of people who contract chickenpox become seriously ill with complications such as pneumonia or encephalitis (inflammation of the brain). About 2,000 of these die. Those who are at higher risk for complications include those with an already weak immune system, those with eczema or other skin conditions, adolescents, and adults.
Adults who get chicken pox usually have a much more severe, prolonged case than children. Pneumonia is common. The rate of hospitalization for chickenpox is almost 900% higher in adults than in children. Adults are more than 20 times more likely to die from this disease. Pregnant women face the additional fear of serious, even fatal, damage to the baby developing within. Clearly it is beneficial to prevent chickenpox in adults.
In the recent past, the primary benefit of getting chickenpox as a child was the likelihood of attaining lifetime immunity. While 10-20% of people who had had chickenpox would eventually develop shingles (a condition characterized by numbness, itching, or severe pain that lasts for 2-3 weeks), most would not get chickenpox again. This may now be changing in areas where the chickenpox vaccine is common. In the past, multiple re-exposures helped to keep people’s immunity high. Since the vaccine is now standard in the United States, the frequency of the natural disease should decline. Those who have had chickenpox as children will not be re-exposed as often, if at all. Their immunity may wane over time, making shingles and adult chickenpox even more common than they are now.
To date, those who have received the vaccine have a much lower incidence of shingles than those who actually had chickenpox over the same time period. Those who receive the vaccine also have a dramatically decreased risk of scarring. Finally, studies so far have found the chickenpox vaccine to be highly effective in preventing moderate and severe chickenpox in children (Redbook: Report of the Committee on Infectious Diseases, 2009).
The other major benefit of the vaccine is an economic one. The vaccine reduces the costs related to the disease, including the costs of missed work, school, and child-care. This economic factor is a major force in the drive for universal immunization in the United States.
The American Academy Pediatrics currently recommends two doses of the chickenpox vaccine. Typically, the first dose of the vaccine is given at 12 to 15 months of age and the second at 4 to 6 years of age (at school entry). Older children who have not received two doses of the vaccine can receive their catch up shots 28 days apart.
What are the risks of the vaccine? For each individual, the vaccine seems quite safe. A chickenpox vaccine was developed in Japan twenty-five years ago. It has since been given to over 2 million people, with a good track record of safety. A similar vaccine has been in use in the United States since the early 1980’s. There is no thimerosal or other preservatives in the vaccine. Reported adverse effects are generally mild — soreness, swelling, or a rash (at the injection site), and fever, tiredness, or fussiness are the most common. The vaccine is not recommended for immunocompromised people, or for pregnant women.
For the environment, the risks increase the more effective the vaccine. If chickenpox — an old, familiar opponent with which we have developed a stable relationship — were eliminated, this might create a niche in the microscopic environment for a new, unknown, potentially more virulent, human virus.
The bottom line: While I remain unconvinced of the long-term wisdom of immunizing everyone against this generally mild disease, the benefits of the vaccine seem to me to outweigh the risks for:
- children with eczema (or other chronic skin conditions), asthma (or other chronic lung conditions), or a strong family history of allergic conditions;
- adolescents or adults who have not yet had chickenpox; and
- those who live in areas where immunization is widespread.
Before the vaccine became available, my three oldest children suffered through the chickenpox. Last week, I chose to give my youngest child the chickenpox vaccine simply because we live in an area where the immunization is widespread and I felt it was in his best interest to be vaccinated.