Adolescent Meningitis Vaccination Program Found to Boost Herd Immunity at All Ages

Researchers at the University of Oxford today reported the results of a large-scale study examining the impact of the UK’s MenACWY vaccination program on the carriage of meningitis bacteria in the throats of British teenagers. They demonstrated the vaccine’s effect on creating a herd defense, also called herd immunity, that protects all age groups

In a study published in Clinical microbiology and infection, researchers took throat swabs and assessed the prevalence of meningitis-causing bacteria before and after the introduction of the vaccination program, using two cross-sectional studies conducted almost four years apart. They found vaccine the carriage of meningococcal groups W and Y is significantly reduced, and the level of group C remains low.

In 2015, in response to an increase in cases of meningitis caused by W and Y strains since 2009, the UK replaced the C-only vaccine (introduced in 1999) with the quadrivalent MenACWY vaccines. To increase the level of collective immunity, the vaccination program included adolescents aged 14 to 19 years, where meningococcal transmission is known to be the highest.

One of the lead authors, Matthew Snape, who was professor of paediatrics and vaccinology in the Oxford Vaccine Group at the time of the study, says: “These studies report on the results of throat swabs taken from more than 24,000 teenagers over 170 years. secondary schools across the country, demonstrating once again the fantastic enthusiasm of the British public for research engagement.”

“The results show us that by immunizing teenagers with MenACWY vaccines, we not only protect them directly, but also reduce the risk of everyone else suffering from meningitis and sepsis from these bacteria.”

“Immunizing teenagers rather than infants means we get more benefit from each dose administered. So these two studies provide invaluable data to help us use these vaccines effectively both in the UK and abroad.”

Researchers compared two studies, the UKMenCar4 study, which was conducted between September 2014 and March 2015 before the MenACWY vaccine was introduced, and the Be on the TEAM study, which was conducted between March 2018 and November 2018 after the vaccine was introduced.

Data from 24,062 students aged 15 to 19 were included: 10,624 from UKMenCar4 and 13,428 from Be on the TEAM. The researchers concluded:

• C, W and Y meningococcal carriage decreased from 2.03% to 0.71%;
• group W shipments decreased from 0.34% to 0.09%;
• group Y transportation decreased from 1.6% to 0.5%; and
• carrier group C remained rare (0.07% to 0.13%).

The findings are consistent with data from the UK showing that the incidence of MenW has fallen across the board age groups since the teenage MenACWY vaccine campaign; not only in teenagers themselves. Taken together, these data provide compelling evidence for the need to target age groups with high rates of meningococcal transmission to maximize the use of these vaccines, and not necessarily immunize other high-risk age groups (such as infants), the researchers added.

Martin Mayden, Professor of Molecular Epidemiology in the Faculty of Biology at the University of Oxford, lead author of the paper, says they have “systematically investigated meningococcal vaccination and its impact on carriage in Oxford since 1999. These studies have been crucial in ensuring the most effective use of the meningococcal vaccine worldwide “.

“Combined with our work with colleagues at Public Health England (now HSA), which characterized the MenW epidemic variant at the genomic level, this work helped to stop an epidemic that likely affected thousands of people. This demonstrates the importance of ongoing urgent research that allows us to anticipate epidemics and pandemics and allow them to be limited before they too seriously affect the population.”

Dr Tom Nutt, chief executive of the charity Meningitis Now, which played a key role in facilitating Be on the TEAM, says: “Meningitis is a devastating disease that can strike anyone at any time and leave a devastating impact. Many youth will know of someone in their community whose life, as well as the lives of their family and friends, has been torn apart by its impact.”

“We are delighted to see that this important study has shown such positive results, not only for the health of young people, but for society as a whole. We now need to redouble our efforts to encourage all those eligible for the free MenACWY vaccination to take advantage of it.”

Liz Rogers, head of research at the Meningitis Research Foundation, who was instrumental in getting the team involved, says they are “delighted to contribute to this important research initiative, which has provided evidence that protection from the MenACWY vaccine extends to a wider population”.

“With many teenagers across the country about to enter or return to university, achieving high uptake of the MenACWY vaccine is increasingly important, so we encourage all teenagers and young adults to check that they have had their routine vaccinations.”

Professor Nick Lemoine of the National Institute for Health and Care Research (NIHR) says “this NIHR-supported study has provided important evidence of the effectiveness of MenACWY vaccines in inducing population immunity against meningitis, which has been shown to protect against of all ages is a potentially life-threatening disease. We want to thank the incredible 24,000 teenage participants who took part for their contribution.”

Health and Mental Health Minister Dr Caroline Johnson says “this study shows why the MenACWY vaccination program is so important in enabling young people to protect themselves and in turn all age groups from this potentially life-threatening disease”.

“Vaccination remains the best line of defense against infectious diseases, including meningitis, and I encourage everyone who is eligible to get the free shot.”