The U.S. Centers for Disease Control and Prevention (CDC) said in a report that chickenpox has continued declining in the country since the second dose of a vaccine was recommended in 2006. There has been an 85 percent drop in the disease caused by the varicella-zoster virus.
The most significant decrease has been among children aged 5 to 14, who are most likely to have received the 2-dose varicella vaccine. U.S. health officials recommend parents to get their kids receive their first dose at age 12-to-15 months and the second shot once they are 4 to 6 years old.
Children may also receive the measles, mumps, rubella and varicella (MMRV) vaccine, which follows the same vaccine schedule but protects them against these diseases. Parents can also choose to give their children varicella and MMR vaccines separately provided that all of them together provide the same level of protection than the vaccines administered separately.
Each year, vaccination has prevented more than 3.5 million cases of chickenpox, 9,000 hospitalizations, and 100 deaths, according to the CDC. The disease was so common before vaccination that 4 million Americans on average were affected by the virus annually in the early 1990s. About 13,500 people were hospitalized while 100 to 150 died any given year.
There was a 90 percent decline in chickenpox cases throughout the next decade after the vaccine was launched in 1996, but continued outbreaks led the CDC to recommend the two-dose schedule in 2006.
Although the vaccine can fail to prevent the disease in everyone, people who have received it and contract the disease usually present milder symptoms than unvaccinated patients.
Babies are the most vulnerable group alongside adults with a weakened immune system. Chickenpox causes symptoms such as fever, tiredness, and an itchy, blistery rash.
Scientists say that they can now conduct research to better understand the characteristics of new outbreaks, including the severity of the symptoms, the number of patients hospitalized and whether they received the vaccine, according to the CDC report. Researchers want to find out the reasons behind current cases of severe symptoms and believe it is essential to know whether such cases happen among vaccinated people.
“Further reduction in the number of varicella cases will provide states with increased opportunities for enhancing varicella surveillance and improving the completeness of reporting to monitor the impact of the vaccination program,” study author Adriana Lopez and colleagues wrote, as reported by CBS News.
Chickenpox vaccine’s side effects
Not everyone should get the double dose of the vaccine. People who have experienced life-threatening allergic reactions after their first dose should avoid getting their second shot.
Those severely allergic to neomycin, an antibiotic, or gelatin should not receive any dose. Allergic reactions such as throat and face swelling, weakness, dizziness and a fast heartbeat may not occur right away after getting the vaccine. People who experiment reactions like these a few hours after receiving the dose are advised to seek immediate medical care.
Pregnant women and people who are severely ill at the time of their scheduled vaccination should also not get the vaccine. Health experts recommend women to avoid pregnancy up to a month after receiving a dose.
Source: CBS News