Improving Tdap maternal immunization rate in Saudi Arabia.

Pertussis is a serious and potentially fatal disease in infants too young for vaccination. Despite a high vaccine coverage in children, pertussis continues to occur in unvaccinated infants in the Kingdom of Saudi Arabia (KSA). Available data supports the use of maternal pertussis immunization for preventing pertussis in young infants. In June 2019, the Saudi Ministry of Health recommended maternal pertussis immunization with combined tetanus-diphtheria-acellular pertussis vaccine (Tdap) during every pregnancy. To understand barriers to maternal immunization and identify strategies to improve maternal immunization, we conducted an online survey in November and December 2020, asking 60 obstetricians/gynecologists about their attitudes to maternal pertussis immunization. Fewer than 50% survey respondents considered maternal immunization as part of their role, and only 47% were aware of the national recommendation. Consequently, the uptake of maternal vaccination in KSA may be sub-optimal. The key barriers that hinder obstetricians/gynecologists from recommending maternal Tdap immunization were the anticipation of patient refusal, and their own need for more information/experience about the disease and the national recommendation. Vaccine availability and supply were important barriers, whereas cost/reimbursement and resource issues were of lesser concern. Disseminating evidence based information to physicians, educating pregnant women and addressing public misconceptions.

What is the context?Pertussis (whooping cough) can be life-threatening when it occurs in very young infants.The most effective strategy to prevent whooping cough in young infants is to vaccinate their mothers during the third trimester of pregnancy.Maternal antibodies transferred to the fetus can provide protection against infection until the first routine whooping cough vaccine at 2 or 3 months of age.Maternal pertussis vaccination has been recommended in Saudi Arabia since 2019.What is new?A survey of obstetricians/gynecologists found that almost 50% were unaware of the recommendation, suggesting poor uptake of maternal vaccination.What is the impact?Strategies to improve maternal immunization rates in the Kingdom of Saudi Arabia need to include education of obstetricians/gynecologists, mothers, and the general public about the disease, how it can be prevented, and the benefits and risk of vaccinating versus not vaccinating.

Meningococcal B Immunisation in Adults and Potential Broader Immunisation Strategies: A Narrative Review.

Recombinant vaccines against invasive meningococcal disease due to Neisseria meningitidis serogroup B (MenB) have shown substantial impact in reducing MenB disease in targeted populations. 4CMenB targets four key N. meningitidis protein antigens; human factor H binding protein (fHbp), Neisserial heparin binding antigen (NHBA), Neisseria adhesin A (NadA) and the porin A protein (PorA P1.4), with one or more of these expressed by most pathogenic MenB strains, while MenB-FHbp targets two distinct fHbp variants. While many countries recommend MenB immunisation in adults considered at high risk due to underlying medical conditions or immunosuppression, there are no recommendations for routine use in the general adult population. We reviewed the burden of MenB in adults, where, while incidence rates remain low (and far lower than in young children < 5 years of age at greatest risk), a substantial proportion of MenB cases (20% or more) is now observed in the adult population; evident in Europe, Australia, and in the United States. We also reviewed immunogenicity data in adults from clinical studies conducted during MenB vaccine development and subsequent post-licensure studies. A 2-dose schedule of 4CMenB generates hSBA titres ≥ 1:4 towards all four key vaccine target antigens in up to 98-100% of subjects. For MenB-FHbp, a ≥ fourfold rise in hSBA titres against the four primary representative test strains was observed in 70-95% of recipients following a 3-dose schedule. While this suggests potential benefits for MenB immunisation if used in adult populations, data are limited (especially for adults > 50 years) and key aspects relating to duration of protection remain unclear. Although a broader adult MenB immunisation policy could provide greater protection of the adult population, additional data are required to support policy decision-making.

Epidemiology of Varicella Zoster Virus and Herpes Zoster Virus in Gulf Cooperation Council Countries: A Review of the Literature.

INTRODUCTION: The reactivation of varicella zoster virus (VZV) in previously infected individuals can cause herpes zoster (HZ), which is characterized by a localized, painful dermatomal rash. While there is a global trend of increasing HZ cases, there is a lack of research examining the epidemiology of HZ within the Gulf Cooperation Council (GCC) countries. Therefore, we aimed to critically appraise evidence on VZV and HZ epidemiology in the GCC countries and identify gaps in the current literature. METHODS: A literature review was conducted via a comprehensive appraisal of the literature. PubMed and local-language journals were searched to identify articles related to HZ and VZV published up until 31 January 2022, with a sole focus on the GCC countries. Included studies reported on surveillance data, seroepidemiology, and patient outcomes for HZ and VZV, and comprised primary data reports, case series, case reports, narrative and systematic literature reviews, studies reporting HZ incidence or prevalence, and Ministry of Health reports. RESULTS: Thirteen studies were found that reported on VZV seroprevalence in Saudi Arabia, the United Arab Emirates (UAE), and Qatar, ranging from 15.0% to 92.2%, while no data were identified for Bahrain, Kuwait, or Oman. There was very limited country-wide information on the incidence of HZ in GCC countries, and three identified studies reported HZ prevalence as seen in a single clinic, ranging from 0.62% to 2.3%. A single study from Saudi Arabia and government surveillance data reported on the impact of VZV vaccination on VZV infection, though there was no evidence on the impact of VZV vaccination on HZ. CONCLUSION: There is a clear gap in the literature regarding the incidence of HZ infection, and the impacts of HZ and VZV vaccinations in the GCC countries. Further research into the epidemiology of HZ is necessary to inform the implementation of vaccination programs in the GCC countries.

Meningococcal Disease and Immunization Activities in Hajj and Umrah Pilgrimage: a review.

Invasive meningococcal disease (IMD) outbreaks associated with Hajj and Umrah pilgrimage events in the Kingdom of Saudi Arabia (KSA) are well recognized. Past outbreaks have been associated with substantial intercontinental spread of specific Neisseria meningitidis serogroups. The emergence of meningococcal serogroup W (MenW) was a global concern following the 2000/2001 Hajj outbreaks. Broader compulsory meningococcal serogroups A, C, W and Y (MenACWY) immunization strategies for pilgrims were introduced in response to these events and led to substantial declines in IMD cases associated with these mass gatherings. However, there remains potential for future outbreaks either within KSA during the Hajj or in local populations via pilgrim meningococcal transmission on their return. While the annual Hajj involves pilgrims from over 185 countries, two-thirds of these arrive from 13 countries, chiefly from across South-East Asia, the Middle East and North African (MENA) regions; for which we review the relevant epidemiology of IMD and meningococcal carriage. While disease surveillance is limited and data are often lacking, MenB is an important serogroup associated with IMD and carriage in a number of countries. Available literature suggests that most pilgrims receive polysaccharide MenACWY vaccines (which do not impact carriage and onward transmission) and incomplete compliance with visa/entry immunization regulations is reported. Existing preventative approaches for visiting pilgrims require continued oversight. More complete compliance and switching to the conjugated MenACWY vaccine can provide more robust and broader protection for pilgrims. Additional immunization options could also be considered.

Hepatitis A in the Eastern Mediterranean Region: a comprehensive review.

INTRODUCTION: With 583 million inhabitants, the Eastern Mediterranean Region (EMR) is a worldwide hub for travel, migration, and food trade. However, there is a scarcity of data on the epidemiology of the hepatitis A virus (HAV). METHODS: The MEDLINE and grey literature were systematically searched for HAV epidemiological data relevant to the EMR region published between 1980 and 2020 in English, French, or Arabic. RESULTS: Overall, 123 publications were extracted. The proportion of HAV cases among acute viral hepatitis cases was high. HAV seroprevalence rate ranged from 5.7% to 100.0% and it was decreasing over time while the average age at infection increased. CONCLUSION: In the EMR, HAV remains a significant cause of acute viral hepatitis. The observed endemicity shift will likely increase disease burden as the population ages. Vaccinating children and adopting sanitary measures are still essential to disease prevention; vaccinating at-risk groups might reduce disease burden even further.

What is the context?Hepatitis A is a viral liver disease caused by the hepatitis A virus.It is generally transmitted by ingestion of contaminated food or water or through contact with an infected person.Disease severity increases with age. Children under 6 years of age are usually asymptomatic, while adults are the most affected.Limited information exists on the number of cases and transmission of hepatitis A in the Eastern Mediterranean region, which includes 21 countries and Palestine, as defined by the World Health Organization.What is new?We performed a literature review to summarize data on hepatitis A disease in the Eastern Mediterranean region over the last 40 years (1980-2020). As information for many countries is scarce or outdated, most of the data is from Egypt, Iran and Saudi Arabia.We found that: Hepatitis A virus is the most common cause of acute viral hepatitis.Hepatitis A exposure varied according to the country's income level.Low- and middle-income countries showed a universal immunity to hepatitis A virus, although this is not the case anymore.What is the impact?Hepatitis A infections have decreased worldwide. Lower exposure to the virus has led to an increase in the susceptible population (including adolescent and adults).Hepatitis A vaccination for children and high-risk groups such travelers should be considered in the Eastern Mediterranean region.

The Epidemiology of Invasive Meningococcal Disease in the Kingdom of Saudi Arabia: A Narrative Review with Updated Analysis.

Reducing invasive meningococcal disease (IMD) through MenACWY immunization is a critical healthcare strategy in the Kingdom of Saudi Arabia (KSA). Robust IMD surveillance is essential to help assess the need for additional immunization initiatives in target populations. This is particularly important in KSA, where mass gatherings accompanying Hajj/Umrah pilgrimages have been associated with IMD outbreaks within the local KSA population, and subsequent intercontinental spread via returning pilgrims. This narrative review of the published literature describes the changing epidemiology of IMD in KSA to provide a perspective on the impact of current immunization strategies and potential gaps. As recent published surveillance data are lacking, we also evaluated publicly reported data from the KSA Ministry of Health (MoH) for 2012-2019 to inform more recent IMD trends. Between 1995 and 2011, national surveillance data indicate that 1103 IMD cases were reported in KSA: 60% in 2000-2001, involving two (mainly MenW) outbreaks involving KSA citizens/residents and pilgrims focused in Mecca and Medina. Across 2002-2011, 184 cases of IMD were reported, with a higher proportion occurring in KSA citizens/residents, and with less focus within pilgrimage centers than apparent in previous years. Our analysis of MoH data found that, between 2012 and 2019, 44 IMD cases were reported, all in KSA citizens/residents, and chiefly in children or infants. No pilgrimage-associated outbreaks have occurred since 2001. Serogroup data were available for 62.5% of all cases for 2002-2011; MenW (40.0%), MenA (35.7%), and MenB (16.5%). Serogroup data for 2012-2019 remain incompletely reported, and the existing surveillance system could be improved, as some element of underestimation/underreporting of IMD may exist. While existing MenACWY immunization strategies for KSA citizens/residents and visiting pilgrims have been successful in reducing IMD due to specific serogroups, disease due to MenB remains a potential risk, and additional immunization strategies should be considered.

A review of the experience of childhood hepatitis A vaccination in Saudi Arabia and Turkey: implications for hepatitis A control and prevention in the Middle East and North African region.

In most countries of the Middle East and Northern African (MENA) region, a high hepatitis A virus (HAV) endemicity has been documented. Few others, such as Saudi Arabia and Turkey, are transitioning from high to intermediate endemicity. There is a paucity of recently published HAV disease burden that could be useful to inform or strengthen relevant national hepatitis A vaccination policy and other prevention strategies in the region. This review summarizes information on HAV epidemiology before and after the implementation of a childhood hepatitis A vaccination program in Saudi Arabia and Turkey. In both countries, a clear shift in the age of first HAV exposure has been documented, with more homogeneous trends across regions in Saudi Arabia compared to Turkey. Utilizing the experience of Saudi Arabia and Turkey with hepatitis A vaccination, countries in the region are encouraged to foster discussions on potential vaccination strategies suitable for their own setting.

Systematic review of the rotavirus infection burden in the WHO-EMRO region.

Rotavirus gastroenteritis imposes a heavy burden on low- and middle-income countries. The World Health Organization defines the Eastern Mediterranean region (WHO-EMRO) as a diverse area in terms of socioeconomic status and health indicators. Rotavirus vaccination has been introduced, at least partially, in 19 out of the 22 EM countries; however, vaccine coverage remains low, and data on rotavirus disease burden is scarce.Available data on rotavirus prevalence, seasonality, vaccination status, and genotype evolution was systematically compiled following a literature review that identified 165 relevant WHO-EMRO epidemiology studies published between 1990 and 2017.Although the infectious agents responsible for acute gastroenteritis vary over time, rotavirus remained the leading cause of acute gastroenteritis in children, as seen in 76.3% of reviewed publications. Younger children (<2 years old) were at higher risk and thus increased vaccination coverage and surveillance systems are required to reduce the rotavirus gastroenteritis burden in WHO-EMRO countries.