meningococcal B vaccine

Researchers sought to determine whether the use of meningococcal B vaccine in the UK infant immunization program upheld safety guidelines.

The 4CMenB vaccine received its first license in the year 2013 in Europe. It went through vigorous clinical trials for safety and efficacy. The results from the trials showed more side-effects than expected, such as fever and skin reactions, when the meningococcal B vaccine was paired with other vaccines. The meningococcal B vaccine was still deemed safe enough for future studies.

In the year 2015, the meningococcal B vaccine was added to the United Kingdom’s infant immunization program. It was delivered to children at eight and 16 weeks of age, with a final booster at one year of age. Previous evidence showed a 94% effectiveness score in those taking the vaccine ten months into the program.

This UK study, published in The Lancet Child Adolescent Health journal, aimed to further examine the safety of the vaccine. Bryan and colleagues used the Yellow Card Scheme – a tool used to report adverse reactions to vaccines – to look at meningococcal B vaccine safety.

They used six criteria to assess how adverse the reactions were, ranging from a medically significant reaction to patient death. They looked at children 18 months old or younger. They considered instances of death, local reactions, Kawasaki disease, fever and seizures to be a cause for concern for further analysis.

Side-effects from the immunization

The meningococcal B vaccine was given on its own without other vaccines to avoid the emergence of other symptoms that could occur from mixing vaccines. They found that this independent vaccination scheme did not affect patients’ agreement for the administration of other vaccines at later dates. The researchers administered about 1.29 million doses, not including second or third doses. This is equivalent to about three million doses of the vaccine over 20 months.

Of the doses given, about 52% of yellow card reports were considered to be a cause for concern. There were no reports of bacterial infections. Of all the reports, 364 cases were cases of fever, with 58% of the fever cases being noted as serious. Usually, serious cases meant cases of high fever.

Seizures accounted for 6% of the reports, with more seizures occurring in the following administered doses. Skin infections counted for 41% of the reports, with 120 considered serious. There were three cases of Kawasaki disease, but there is no clear evidence that Kawasaki disease is caused by vaccinations. Unexpectedly, they found cases of subcutaneous nodules that could last for months where the vaccine was administered in a little under half of the cases that had local reactions.  These were not accompanied by other symptoms. Very little could be concluded from these nodules because of lack of sufficient information to explain it.

Limitations of the Yellow Card Reporting Tool

There are limitations to the Yellow Card reporting tool. There may have been under-reporting of reactions. In addition, these reports do not prove that this specific vaccine is what caused the adverse reactions. More data and studies are needed, especially to examine rare adverse events. Electronic data also has its faults. Some examples include the slow transfer of data between hospitals and the possibility of missing data.

Overall, the data was as expected, based on predictions from previous statistical analyses. The vaccine was shown to be beneficial, with little to no safety concerns. The researchers stress the importance of further long-term studies and monitoring of the vaccine to uphold safety standards.

Written by Olajumoke Marissa Ologundudu B.Sc. (Hons)

Reference: Bryan, P. et al. Safety of multicomponent meningococcal group B vaccine (4CMenB) in routine infant immunisation in the UK: a prospective surveillance study. Lancet Child Adolesc Health (2018). http://dx.doi.org/10.1016/S2352-4642(18)30103-2

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