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History of Vaccines Blog
A Monday afternoon session at the National Foundation for Infectious Diseases Annual Conference on Vaccine Research was entitled “Current Challenges in Immunization Policy.” The topics ranged from vaccine hesitancy, effectiveness of acellular pertussis vaccine, and the burden of adverse events from rotavirus vaccination. Saad B. Omer, MBBS, MPH, PhD, of the Emory Vaccine Center, is widely published on vaccine refusal and its consequences in relation to disease. Most of the work he presented Monday explored the relationship between vaccine hesitancy and pertussis incidence.
April 24, 2013
Day 2 of the National Foundation for Infectious Diseases Annual Conference on Vaccine Research included a focus on maternal immunization. Carol J. Baker, MD, of Baylor College of Medicine, opened the session (much to our pleasure!) with the history of evidence of the effectiveness of maternal immunization for preventing disease in newborns via passive transfer of antibodies via placenta or breastmilk. It’s generally accepted that this passive immunity, for some diseases, benefits the baby for about the first six months of life. We haven’t had a chance to look up her references, but she mentioned evidence from 1879 that showed vaccination with vaccinia prevented smallpox in infants, from 1938 showing that maternal immunization with whole-cell pertussis vaccine protected infants from pertussis complications, from 1961 showing vaccine-induced tetanus immunity transfer from mother to baby in New Guinea, and, finally, from 2011 leading to recommendation of pertussis-containing vaccine and influenza vaccine for pregnant women.
On March 13, the Children’s Hospital of Philadelphia Vaccine Education Center sponsored a vaccine update webinar with Paul A. Offit, MD, as the speaker and moderator. Dr. Offit discussed vaccine-related items in the news as well as decisions taken at recent Advisory Committee on Immunization Practices (ACIP) meetings in Atlanta. First on the agenda was a discussion of pertussis vaccine, particularly as it relates to a February 7 letter to the New England Journal of Medicine in which researchers (Queenan, Cassidy, & Evangelista) called attention to new strains of Bordatella pertussis that the group had observed at St. Christopher’s Hospital in Philadelphia. Specifically, these strains were classified as pertactin-negative. Pertactin is a protein that is normally a component of B. pertussis, and it is one several antigenic proteins in acellular pertussis vaccines. The letter questioned whether the acellular vaccine was generating pressure on B. pertussis, thus leading to the emergence of these pertactin-negative strains.
October 26, 2012
As of October 24, 2012, the U.S. Advisory Committee for Immunization Practices (ACIP) recommends to vaccinate all pregnant women against pertussis (whooping cough) with the Tdap vaccine regardless of whether they have had Tdap in the past. If that is not feasible, the vaccine should be given upon discharge from the hospital or birthing center. Giving the vaccine during pregnancy allows for the mother's immune system to make antibodies, that then get transferred to the newborn body through the umbilical cord. This can protect the infant during the time before he or she receives the first set of scheduled vaccines at two months of age. The vaccine was previously recommended to be given to pregnant women who never had the Tdap vaccine, but it has now been determined that a single dose of Tdap vaccine is not enough to protect for additional pregnancies.
May 15, 2012
The Secretary of Health of the state of Washington declared a pertussis epidemic on April 3, 2012, after the number of reported cases reached 640, compared to 94 cases reported in the same time period in 2011. Pertussis, or “whooping cough,” is a respiratory disease caused by the Bordetella pertussis bacteria. After a person becomes infected, it can take from 7 days to a month for pertussis symptoms to develop. The bacteria cause the disease by releasing toxins that lower the lungs’ ability to clear out respiratory secretions (mucus). After an initial period of a low-grade fever and mild cough, the cough becomes severe and occurs in episodes that prevent the patient from breathing properly, so much so that some patients turn blue during the coughing bouts and for a short time after. According to the Centers for Disease Control and Prevention (CDC), 27,550 cases of pertussis were reported to public health authorities in 2010.
July 19, 2011
In October 2010, the Advisory Committee on Immunization Practices (ACIP) issued a new recommendation for Tdap vaccination -- the booster vaccine that provides protection against tetanus, diphtheria, and pertussis (whooping cough). While the vaccine had previously been recommended as a one-time booster for adults up to age 64, replacing an individual tetanus booster, the committee voted to expand that recommendation: anyone older than 65 who had not received a prior dose of Tdap should receive one if they expected to have close contact with an infant younger than 12 months old.
This recommendation was made partially in light of the California whooping cough epidemic. While whooping cough is typically less severe in adults, the infection can still be passed to infants, for whom infections are much more severe. Study data has indicated that grandparents, for example, are the ultimate source of the infection in 6-8% of cases. However, the committee noted that there was a direct benefit to the individual as well, since whooping cough tends to be more severe in adults older than 65 than in younger adults. (For more details, see "Advisory Committee Votes for Expanded Pertussis Vaccine Recommendations" from the History of Vaccines blog.)
Although this recommendation was issued last October, some adults older than 65 who wanted to receive a Tdap booster had difficulties obtaining one due to confusion between the ACIP's recommendation and the FDA's approved label usage for the vaccine at the time. Neither of the two Tdap vaccines (Sanofi Pasteur's Adacel and GlaxoSmithKline's Boostrix) was approved by the FDA for use in adults older than 65.
April 28, 2011
National Infant Immunization Week is April 23-30 this year. This week, the History of Vaccines blog features posts about several diseases that can be prevented by vaccination of infants.
Although its name is not as well known as those of diseases like chickenpox or measles, rotavirus is the most common cause of severe diarrhea in children and infants worldwide. Before a vaccine was introduced in the United States, the disease caused more than 400,000 doctor's visits and 200,000 emergency room visits each year, causing as many as 60 deaths annually in U.S. children younger than five.
The virus spreads easily among children, and can also be passed from children to those with whom they're in close contact. Rotavirus spreads via the fecal-oral route -- that is, from the waste of an infected person to the mouth of another individual. This can occur via contamination on hands or objects like toys.
Rotavirus can be prevented by vaccination. The first dose of the vaccine series is recommended at two months of age.
February 22, 2011
The U.S. Supreme Court ruled on February 22 on Bruesewitz vs. Wyeth, upholding a federal law that established protection for vaccine makers from lawsuits and that provides compensation for certain vaccine injuries.
The Bruesewitz suit claimed that a vaccine Hannah Bruesewitz received in 1992 (her third dose of the diphtheria-whole cell pertussis-tetanus vaccine) was defective in its composition and thus resulted in the girl’s seizures and developmental delays. The Bruesewitz family earlier had been denied compensation from the National Vaccine Injury Compensation Program.
Antonin Scalia wrote the majority opinion, stating that "Vaccine manufacturers fund from their sales an informal, efficient compensation program for vaccine injuries; in exchange they avoid costly tort litigation and the occasional disproportionate jury verdict." He asserted that the intention of the National Childhood Vaccine Injury Act of 1986 (which established NVICP) to exclude drug design defects from liability claims is evident in its “lack of guidance for design defects combined with the expansive guidance for the grounds of liability specifically mentioned.”
October 27, 2010
Meeting in Atlanta, the Advisory Committee on Immunization Practices voted on October 27 for new recommendations regarding Tdap vaccination.
Tdap, the booster vaccine for tetanus, diphtheria, and pertussis (whooping cough) has been a source of confusion in recent months. In light of the pertussis outbreak that began in California, health authorities had issued reminders about the adult Tdap recommendation: adults aged 19-64 should substitute one Td booster (recommended every ten years to protect against tetanus and diphtheria) with a single Tdap booster, which also offers protection against pertussis. This is recommended to limit the disease's ability to spread; while adult pertussis cases are generally milder than those in children, adult patients can still spread the disease to young children, including those too young to be vaccinated. The adult vaccination schedule did not include a recommendation about Tdap for adults aged 65 and older, however, which includes many grandparents concerned about passing pertussis on to their grandchildren.
A post on the History of Vaccines blog earlier this month mentioned an outbreak of whooping cough in California, noting that at the time, four infants had already died from the disease. The death count has now reached five, all children less than three months of age, and the total number of confirmed cases reached 910 as of June 15th. The director of the California Department of Public Health declared in a statement that the outbreak is now an epidemic.
The most recent major outbreak of whooping cough was in 2005, when 3,182 cases were recorded in California. This year’s epidemic is on pace to surpass the number of cases from 2005. An outbreak has also been reported in Ohio, and Oregon public health officials have reportedly noted an unusually high number of cases there as well.
Whooping cough can be prevented by vaccination, but the first dose of the vaccine is not given until two months of age. Prior to that infants are highly susceptible to the disease, which is often spread by adults. A booster vaccine against whooping cough is available for adults as part of the Tdap (tetanus, diphtheria, pertussis) immunization, which can be substituted for one tetanus or Td vaccination between the ages of 19 and 64. The Advisory Committee on Immunization Practices (ACIP) recommends Tdap vaccination for adults who have contact with infants younger than 12 years of age.