December 28, 2016
By Will Boggs MD
NEW YORK (Reuters Health) - The quadrivalent meningococcal conjugate vaccine appears safe for adolescents and young adults, despite a possible association between the rare occurrence of Bell's palsy and receipt of the vaccine concomitantly with other vaccines.
"Among 26 pre-specified events that were examined in the study, only one event (Bell's palsy) was found to have some temporal association (5-10 weeks after vaccination) with the vaccine (Menveo) given concomitantly with other vaccines (Tdap, flu, or HPV)," Dr. Hung-Fu Tseng from Kaiser Permanente Southern California, Pasadena, California told Reuters Health by email. "The association could be due to chance alone or due to some recipients have conditions predisposing them to Bell's palsy."
The case-fatality rate of meningococcal disease is as high as 14% among adolescents, and 11% to 27% of survivors experience significant sequelae. The Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices recommends routine vaccination with meningococcal vaccines for individuals ages 11 through 18 and for others who are at an increased risk of invasive meningococcal infection.
Dr. Tseng and colleagues used data from three Kaiser Permanente medical centers to evaluate the safety profile of GlaxoSmithKline's quadrivalent meningococcal conjugate vaccine among 48,899 individuals ages 11 to 21.
Using a self-controlled case series method, they found significantly increased rates for only one of the 26 prespecified events of interest, according to the December 26th Pediatrics online report.
The risk of Bell's palsy increased 2.9-fold in the 12 weeks after receipt of the vaccine. In stratified analyses, the increased risk was apparent only among individuals receiving concomitant vaccines.
In all eight cases, Bell's palsy resolved completely.
There were no significant increases in the risk of Guillain-Barre syndrome, myasthenia gravis, multiple sclerosis, rheumatoid arthritis, juvenile diabetes, Graves disease, asthma, or any of the other events of interest.
"This observational study was not intended to provide conclusive evidence of causality," the researchers note.
"The possible link between receiving several vaccines (including the meningococcal vaccine) concomitantly and a mild form of Bell's palsy needs further evaluation," Dr. Tseng said.
"The vaccine is generally safe," Dr. Tseng concluded. "The possibility of temporal association between concomitant vaccination (including Menveo) and Bell's palsy should be weighed against the risk of severe consequences of meningococcal infection."
Dr. Lee H. Harrison from the University of Pittsburgh's Infectious Diseases Epidemiology Research Unit told Reuters Health by email, "As an exploratory study that requires confirmation, I do not believe that the evidence is strong enough to indicate a causal relationship at this point. Therefore, in my opinion, this study should not influence informed consent discussions about meningococcal vaccines. That said, physicians should be prepared to discuss the study if patients bring it up."
"Meningococcal disease can be devastating and result in death and severe, permanent sequelae," he said. "Meningococcal vaccines are safe and effective and should be administered according to ACIP guidelines."
"Be on the lookout for additional studies that confirm or refute the findings of this exploratory study," Dr. Harrison added.
Dr. Anna-Lisa Farmar from Denver Health and the University of Colorado in Aurora told Reuters Health by email, "With any informed consent discussion with parents regarding vaccination, I think it is important to remind parents that the vast majority of possible adverse events are rare and pale in comparison to the diseases the vaccines prevent, many of them potentially fatal. In this study, all eight of the reported cases of Bell's Palsy completely resolved, whereas the complications of actual meningococcal disease include serious permanent sequelae and death."
"For physicians who have children, it can also be helpful to share our own choices to vaccinate our kids despite the potential adverse events," she said. "I regularly let my patients' parents know that I vaccinate my children according to the schedule recommended by ACIP, and for vaccine-hesitant parents this knowledge can reassure them about their choice to proceed with vaccination."
Novartis Vaccines and Diagnostics, Inc., now part of GlaxoSmithKline Vaccines, sponsored the trial, employed three of the 14 authors, and provided research support to the other 11 authors.
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