Your companion on the red-eye from Dulles airport to Geneva is a two inch-thick Yellow Book—478 pages of previous meeting notes, disease eradication plans, reviews of evidence, references, and more related to the meeting of WHO’s Strategic Advisory Group of Experts (SAGE)—including at least seven global policy questions you will need to make a decision about. All this in 30 hours of meetings over three days.
Feeling fuzzy getting off your flight? Grab a double expresso as you are head over to WHO HQ on Avenue Appia. Outcomes of these meetings will inform WHO’s Director-General and lead to new recommendations from WHO for all countries on the best ways to ensure vaccines improve health and save lives for as many people as possible.
Welcome to SAGE!
IVAC's Delegation at SAGE 2017
From October 17-19, three faculty members from the International Vaccine Access Center (IVAC), of the Johns Hopkins Bloomberg School of Public Health (JHSPH), provided technical expertise and leadership at the annual SAGE meeting, an advisory body formed in 1999 to provide guidance on immunizations to the WHO.
IVAC’s delegation included Director of Epidemiology Bill Moss, Director of Science Maria Deloria Knoll, and IVAC Executive Director Kate O’Brien. The meeting, held in the August Room where WHO’s 34-member Executive Board meets, was attended by about 200 people and included presentations from nine Working Groups. SAGE Working Groups delve in to key immunization-related questions of interest to policymakers around the world.
The Executive Board’s elevated screen helps viewers sitting on multiple tiers follow presentations. Maria’s purple sweater helped people locate her in the immense room.
How did IVAC members at SAGE support policy-making for WHO?
Measles and Rubella
Dr. Moss, who also serves as a Professor in the Departments of Epidemiology, International Health, and Molecular Microbiology and Immunology (MMI) at JHSPH, has been a member of SAGE’s Measles and Rubella Working Group since 2011. Dr. Moss presented evidence supporting a recommendation that people living with HIV do not need to be re-vaccinated against measles if they were not infected with HIV at the time of their measles vaccination in young childhood. This policy has implications on the estimated 34.5 million adults living with HIV infection and on the achievement of measles elimination goals.
Dr. O’Brien, who is a Professor in both Departments of International Health and Epidemiology at JHSPH, has served as a SAGE member since 2012 and has participated in multiple Working Groups over the past four years. This year Dr. O’Brien chaired the SAGE Working Group on rabies vaccines and rabies immunoglobulins, which are antibodies that recognize and bind to the rabies virus to destroy it. Sidebar… Dr. O’Brien’s analysis of rabies vaccine policy became personally relevant during a holiday in Mexico: a bat flew into her son Jack’s face and sent them on a complicated journey to locate rabies immune globulin and vaccine (fortunately, they found them both and Jack remains healthy!).
Pneumococcal conjugate vaccine
Dr. O’Brien also co-led the Pneumococcal Conjugate Vaccines Working Group (more about this below). During this meeting, Dr. Knoll, who serves as an Associate Scientist in the JHSPH Department of International Health, presented on a review IVAC authored of over 200 studies assessing the effect of both of WHO’s recommended dosing schedules on vaccine-type disease, or the strains of pneumococcus included in the 10- and 13-valent conjugate vaccines.
Recommendations to WHO Director-General
Dr. O’Brien and the other 14 members of SAGE—each representing a different institution and country—considered the evidence and made formal recommendations to WHO. For example, based on the evidence presented, SAGE concluded that both WHO-recommended PCV schedules have a substantial impact on reducing vaccine-type disease. All evidence presented during the meeting is available in the Yellow Book.
How SAGE gathered evidence to optimize the impact of pneumococcal conjugate vaccines
Starting in January, the pneumococcal conjugate vaccines (PCV) working group, led by SAGE members Dr. O’Brien and Dr. Andrew Pollard of the University of Oxford, reviewed extensive evidence on PCV impact. One of the main sources of evidence was the PCV Review of Impact Evidence (PRIME) Systematic Review, an effort co-led by IVAC with partners including the US CDC, WHO, the University College of London, and Agence de Médecine Préventive. Over the past two years, the PRIME group reviewed studies to assess differences in disease, immunogenicity, and carriage impact by PCV schedule and product, as well as evidence of immunogenicity of catch up immunization. This systematic review served as an update to a previous review conducted by IVAC, which compared impact of different schedules in the context of PCV7 use and served as an important evidence base for previous SAGE WHO PCV recommendations.
Among the PRIME review’s findings on PCV schedules:
Immunogenicity: A 3-dose primary series induces a greater immune response compared to a 2-dose primary series. However, in a 3-dose schedule, the third dose is more immunogenic when given as a booster (2+1) for most serotypes. It is important to note that greater immunogenicity may not necessarily mean better protection from disease.
Nasopharyngeal Carriage: Both schedules showed an impact on overall vaccine serotype carriage (product specific vaccine-type).
Invasive Pneumococcal Disease: Both schedules showed impact on overall vaccine-type invasive disease. For serotype 1, the 2+1 schedule showed clear evidence of impact from a substantial body of evidence; for the 3+0 schedule although some impact was seen the data were more limited.
WHO’s recommendations related to dosing schedule, catch up vaccination, and product usage will be published in a PCV Position Paper in 2018. If there are opportunities to improve impact, countries using pneumococcal vaccines may consider update their schedule and product choices.
In the meantime, we’re clearing off our bookshelf space for the next onslaught of documents… SAGE will re-convene April 17-19, 2018 – see you there!
For more information, see the resources below: