The multicomponent serogroup B meningococcal (4CMenB) vaccine was recently tested for the persistence of antibodies in children at five-years-old by examining different schedules of vaccination. Researchers from the University of Oxford and Novartis (the 4CMenB vaccine manufacturer) looked at children of kindergarten age about 18-20 months after their last dose of the 4CMenB vaccine who had been enrolled in a previous randomized trial. The researchers also looked at 50 vaccine-naive children of the same age after the administration of two doses of the 4CMenB meningococcal vaccine. For the study, researchers measured antibodies “against 4 indicator strains of serogroup B meningococcus matched to each individual vaccine component and against 4 mismatched strains,” according to the Canadian Medical Association Journal.
The authors said that the objective of the study, registered at ClinicalTrials.gov as trial number NCT01027351, was to explore antibody persistence in vaccinated 40-month-old children compared to vaccinated 60-month-old children about a year and a half after they are given an additional booster shot. Another objective of the trial, as listed by the authors, was to determine the safety of the 4CMenB and how well children tolerated a booster shot of the 4CMenB at 40-months-old.
Children were excluded from the trial if they had any symptoms believed to be caused by N. meningitidis, according to the authors. Children who had a history of severe allergic reactions or hypersensitivities to any previous vaccines or vaccine components were also excluded from the vaccine trial intended to measure the safety and persistence of antibodies from the 4CMenB by Novartis. All children with any serious chronic or progressive diseases were also excluded. Similarly, children who had suspected or diagnosed impairments or alterations of the immune system were excluded from the trial.
Between 44 and 88 percent of children who were in groups given the 4CMenB vaccine at two, four, six, 12 and 40 months of age had protective antibody titres against vaccine-matched strains when they were five-years old, according to the study’s authors. Between 13 and 81 percent of children in groups vaccinated on this same schedule had protective antibody titres against mismatched strains of the disease. Similar findings were shown in other test groups.
“Loss of protective titres was also observed for those who received the 4CMenB vaccine at 12, 40 and 42 months (n = 5) (80%–100% against matched strains, 60%–100% against mismatched strains) or at 40 and 42 months (n = 29) (31%–100% against matched strains, 41%–81% against mismatched strains).”
When the 4CMenB vaccine was given to five-year-old vaccine-naive children, the protective titers against matched strains could be found in between 92 and 100 percent of the children and protective titers against mismatched strains could be found in between 59 and 100 percent of the children.
The authors said that the results of this clinical trial gives researchers important new information about the 4CMenB vaccine that is dependent on the test strains and the vaccination schedule itself. The authors further suggested that the introduction of the 4CMenB into the UK routine immunization schedule could allow researchers to study the effects of the vaccine in a real-world setting, according to the Canadian Medical Association Journal.
“Introduction of the 4CMenB vaccine into the UK’s routine immunization schedule provides an ideal opportunity to assess the effect of this vaccine in a real-world setting and will guide the implementation of 4CMenB vaccination in Canada and worldwide.”
The study concluded that by five-years-old, waning of immunity occurred if the 4CMenB vaccine in given during infancy, even when children were given another booster when they were 40-months. The authors said, “The 4CMenB vaccine is immunogenic and was fairly well tolerated by 5-year-old children, although injection-site pain was noteworthy.” The study showed few serious adverse events and other events that were reported were primarily associated with redness and pain, according to the authors.
Serogroup B meningococcal disease is known to be the leading cause of meningitis and the leading cause of blood infections in developed countries like the United States and Canada, according to the CMAJ, and children under five-years-old are considered especially at risk, with another peak in cases associated with late adolescence. Novartis announced in January that the U.S. Food and Drug Administration (FDA) granted accelerated approval of its 4CMenB vaccine licensed as Bexsero® for people between the ages of 10-years-old through 25-years-old and will complete ongoing studies to confirm effectiveness. Other meningococcal vaccines (Menactra®, Menveo®, MenHibrix®) are recommended for some children less than 10-years-old in the U.S., but only if their risk is high, according to the CDC. Public Health Agency of Canada currently recommends Novartis’ 4CMenB vaccination only for those in defined high-risk groups.
[Photo credit: Novartis AG/Flickr]
Novartis’ 4CMenB Meningococcal Vaccine Wanes By Kindergarten Age In Clinical Trial is an article from: The Inquisitr News
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