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The Vaccine for chickenpox by Merck

November 29, 2001: CDC REMINDER: VARICELLA, MMR VACCINES SHOULD BE GIVEN AT LEAST 30 DAYS APART The US Centers for Disease Control and Prevention has affirmed its recommendation that physicians should either administer varicella vaccine simultaneously with the measles-mumps-rubella (MMR) vaccine or wait at least 30 days if the vaccines are administered separately.
Chickenpox Vaccine Deemed Safe And Effective Reuters Thursday, March 29, 2001 By Suzanne Rostler 
NEW YORK, Mar 28 (Reuters Health) - The days of "chickenpox playgroups" may have gone the way of pine-paneled station wagons and wall-to-wall shag, replaced by a simple shot in the arm, study findings suggest. The chickenpox vaccine became available in the US in 1995 and is now recommended by the American Academy of Pediatrics (AAP) for healthy children 12 months and older who have not had chickenpox. Dr. Marietta Vazquez of Yale University in New Haven, Connecticut, and her colleagues are conducting an ongoing trial of the vaccine. The vaccine is safe and is 97% effective in protecting children aged 12 months to 16 years from contracting a severe form of the disease. While 86% of the 56 vaccinated children in the study who developed chickenpox had a mild form of the disease, only 48% of the 187 unvaccinated children with chickenpox did, the researchers report in the March 29th issue of The New England Journal of Medicine. Chickenpox can lead to more serious complications in adults. For this reason, generations of parents have knowingly exposed their children to other kids with the virus, since an estimated 90% of unvaccinated people will catch the disease when exposed to an infected person. But while many children contract and recover from chickenpox through these gatherings, known as chickenpox playgroups, others have experienced serious complications including encephalitis (inflammation of the brain), pneumonia and death. According to the AAP, about 4 million cases of chickenpox occurred in the US each year before the introduction of the varicella vaccine, resulting in 10,000 hospitalizations and 100 deaths. Further, chickenpox is occurring among younger children, who are more susceptible to group A streptococcus bacterial infections. These bacteria cause mostly mild infections such as strep throat, but in rare instances can lead to more serious infections including necrotizing fasciitis and streptococcal toxic shock syndrome. "These results indicate that the effectiveness of the varicella vaccine as it is used in actual practice is excellent, at least in the short term," Vazquez and colleagues write. How long immunity from one shot will last, they note, remains unclear. Previous studies have shown that the vaccine used in the current study can cause mild side effects such as rash, fever, sore throats and cold-like symptoms, and that the rate of more serious side effects is extremely rare. The current report did not investigate side effects. Last year, the US Centers for Disease Control and Prevention recommended that children be vaccinated against the chickenpox virus before entry to childcare facilities and elementary schools. "It is important for all susceptible persons, adults as well as children, to get vaccinated against varicella," Vazquez stressed in an interview. Immunizing children "not only provides them with protection against the disease but prevents them from becoming susceptible adults." SOURCE: The New England Journal of Medicine 2001;344:955-960, 1007-1009. 

The true history of the vaccine for chickenpox

I attended a scientific conference, held by the Varicella Zoster Research Foundation, in 1997, and had the opportunity to actually meet the Japanese doctor who developed the original vaccine for chickenpox. In 1964, during his research fellowship at Baylor Medical College in Houston, Dr. Takahashi's three-year-old son suffered from a severe case of chickenpox. He remembers asking himself, "What if chickenpox could be prevented by a vaccine?" Eight years later, he isolated a strain of varicella virus from a child with chickenpox. That viral strain was used to develop the first chickenpox vaccine in Japan and later in the United States." Merck & Co., Inc. took it from there. Varivax was licensed by the FDA, after over a decade of testing, on St. Patrick's Day, March 17, 1995. Now we have a safe and effective vaccine for chickenpox.


Date last modified: October 16, 2007