Seroconversion rates following 2 doses of measles- mumps- rubella vaccination given at the ages 12 and 18 months: data for possible additional dose at older age

Background Despite high rate of vaccination coverage with 2-doses of measles containing vaccine among Iranian children, outbreaks of measles occurred among different age groups and fully vaccinated subjects. Although the main reason for these outbreaks is unknown, however, vaccine failure was supposed to be an important cause. This study was designed to determine the seroconversion rates to measles- mumps- rubella (MMR) vaccine currently in use among Iranian children. Methods This prospective study was conducted among healthy children older than 12 months who were candidates of scheduled MMR vaccination. Blood samples were obtained from each mother- infant pair just before vaccination, and from infants 4–6 weeks after MMR1 and MMR2 immunization. Collected sera were tested for specific lgG antibodies against MMR agents using ELISA method. The proportion of seroprotected subjects among mother- infant pairs before vaccination as well as the prevalence rates of seroconversion after MMR1 and MMR2 vaccination were calculated. Collected data were analyzed using descriptive statistical methods. Results During 22-months study period, 92 mother- infant pairs were participated. Seroimmunity rates against MMR viruses were 85.8%, 84.7% and 86.9% for mothers, and 3.2%, 2.1% and 1.0% for children, respectively. After MMR1 vaccination from 52 seronegative children, 80.7%, 78.8% and 75% were seroconverted. These rates increased to 94.8%, 89.7% and 94.8% after the MMR2 vaccination. Also, the specific immunity was enhanced among seropositive children. Conclusion Majority of the mothers and few infants were immune to MMR viruses prior to MMR1 vaccination. Immune responses detected after MMR1 injection, and overall seroconversion rates achieved after 2-doses of MMR vaccination were less than expected and inadequate to preserve long-term protection against MMR agents.

Epidemiology of mumps outbreaks and the impact of an additional dose of MMR vaccine for outbreak control in regional Queensland, Australia, 2017–2018

Background In recent years, there have been ongoing outbreaks of mumps reported in Northern and North-Western Queensland, Western Australia and the Northern Territory, Australia. We aimed to define the epidemiology of mumps outbreaks in Central Queensland, Australia between October 2017 and October 2018 and evaluate the effectiveness of an additional dose of measles, mumps, rubella (MMR) vaccine. Methods A retrospective case control study was conducted, including outbreak investigations with laboratory-confirmed cases of mumps and subsequent comparison with matched controls. We analysed mandatory notifications from the Queensland Health Notifiable Conditions System database and immunisation information from the Queensland Health Vaccination Information and Admin System (VIVAS) and the Australian Immunisation Register. Results Between October 2017 and October 2018, there were 93 cases of mumps reported in Central Queensland with three distinct outbreaks: a discrete Indigenous community; a correctional facility; and a boarding school. Among all cases, 74 (79.6%) were fully vaccinated and 14 (15.1%) were partially vaccinated with MMR vaccine. Eighty-six cases (92.5%) were reported among Aboriginal and Torres Strait Islander people. In all outbreaks, an additional dose of MMR vaccine was offered with 35.4%, 73.6% and 35.8% of the target population being immunised in the discrete Indigenous community, the correctional facility and the boarding school, respectively. Prior to this additional dose of MMR, the mumps attack rate was 31.0 (95% confidence interval [95% CI]: 24.2–39.0) per 1000 population, compared to the post-additional dose MMR attack rate of 10.6 (95% CI: 6.7–15.9) per 1000 population. Conclusion An additional or booster dose of MMR should be included as an effective public health intervention strategy, particularly in communal or high-density living conditions to control mumps outbreaks in highly vaccinated populations.

Antecedents of Vaccine Hesitancy in WEIRD and East Asian Contexts

Following decreasing vaccination rates over the last two decades, understanding the roots of vaccine hesitancy has become a public health priority. Vaccine hesitancy is linked to scientifically unfounded fears around the MMR vaccine and autism which are often fuelled by misinformation spread on social media. To counteract the effects of misinformation about vaccines and in particular the falling vaccination rates, much research has focused on identifying the antecedents of vaccine hesitancy. As antecedents of vaccine hesitancy are contextually dependent, a one-size-fits-all approach is unlikely to be successful in non-WEIRD (Western, Educated, Industrialised, Rich, and Democratic) populations, and even in certain (non-typical) WEIRD sub-populations. Successful interventions to reduce vaccine hesitancy must be based on understanding of the specific context. To identify potential contextual differences in the antecedents of vaccine hesitancy, we review research from three non-WEIRD populations in East Asia, and three WEIRD sub-populations. We find that regardless of the context, mistrust seems to be the key factor leading to vaccine hesitancy. However, the object of mistrust varies across WEIRD and non-WEIRD populations, and across WEIRD subgroups suggesting that effective science communication must be mindful of these differences.

Number of doses of Measles-Mumps-Rubella vaccine applied in Brazil before and during the COVID-19 pandemic

Background Due to the social isolation measures adopted in an attempt to mitigate the risk of transmission of SARS-CoV-2, there has been a reduction in vaccination coverage of children and adolescents in several countries and regions of the world. Objective Analyze the number of doses of vaccine against Measles-Mumps-Rubella (MMR) applied before and after the beginning of mitigation measures due to COVID-19 pandemic in Brazil. Methods The data collected refer to the number of doses of the MMR vaccine applied monthly to the target population residing in Brazil: cahildren, aged 12 months (first dose) and children, aged 9 years (second dose), from April 2019 to December 2020. Differences in MMR vaccine doses from April 2019 to March 2020 (before the start of mitigation measures) and April 2020 to September 2020 (after the start of the mitigation measures) were evaluated. Spatial analysis identified clusters with a high percentage of reduction in the median of applied doses no Brazil. Results There was a reduction in the median of doses applied in the Regions North (− 33.03%), Northeast (− 43.49%) and South (− 39.01%) e nos Estados Acre (− 48.46%), Amazonas (− 28.96%), Roraima (− 61.91%), Paraíba (− 41.58%), Sergipe (− 47.52%), Rio de Janeiro (-59.31%) and Santa Catarina (− 49.32) (p < 0.05). High-high type spatial clusters (reduction between 34.00 and 90.00%) were formed in the five regions of Brazil (Moran’s I = 0.055; p = 0.01). Conclusion A reduction in the number of MMR vaccine doses was evidenced as a possible effect by the restrictive actions of COVID-19 in Brazil.

KNOWLEDGE AND ATTITUDE OF MOTHERS TOWARDS MEASLES AND MEASLES, MUMPS AND RUBELLA (MMR) VACCINE IN IDI- ABA COMMUNITY ABEOKUTA, NIGERIA

Measles has remained endemic in some part of the world where the vaccine is not easily accessible. Although vaccine is available in some parts of the world, with routine immunization services and campaigns, many children are yet to be vaccinated. Hence, this study assessed the knowledge and attitude towards measles and Measles, Mumps and Rubella vaccine (MMR) among mothers in Idi-aba community. This was a descriptive research design using multistage sampling technique to choose participants for the study. A self-constructed questionnaire was used to collect information from participants. After the distribution and collection of the questionnaires, data was analyzed using descriptive statistics. Results showed that 93.2% (386) and 65.9% (273) participants indicated that they knew what measles and MMR vaccines are respectively. However, overall analysis revealed that only 165 (39%) participants had high knowledge of measles and MMR vaccine while 303 (74%) had good attitude towards measles and MMR vaccine. This study showed that there are some knowledge gaps. Factors significantly associated with high percentage of mothers having good attitude are occupation (????2=20, P=0.000), income (????2=5.9, P=0.009) and parity (????2=23, P=0.000). In conclusion, this result implies that in order to sustain the good attitude displayed by the mothers, there is need for strategic intensive health educational programs for the mothers of the community.

Safety of Live-Attenuated Measles, Mumps, and Rubella Vaccine Administered Within 2 Years of Hematopoietic Cell Transplant

Background Measles, mumps, and rubella (MMR) vaccine is a live-attenuated vaccine usually contraindicated within the first 2 years of hematopoietic cell transplant (HCT). The objective of this study was to assess the safety of MMR vaccine when administered within 2 years of HCT. Methods We conducted a retrospective review of patients who received MMR vaccination within 2 years of an autologous or allogeneic HCT, mostly in the context of the 2019 measles outbreak. Adverse reactions were collected for 42 days postvaccination, and all hospitalizations and deaths following vaccination were reviewed. Results A total of 129 patients (75 autologous and 54 allogeneic HCT) were vaccinated 300–729 days after HCT (median, 718 days), and 39 (30%) of these were vaccinated earlier than 23 months post-transplant. Ten adverse reactions in 7 patients (5%) were identified within 42 days of vaccination: 6 respiratory tract infections (3 with fever) and 1 rash. The rash was seen in a 37-year-old female who had an allogeneic HCT 542 days before vaccination. She presented with a centrifugal maculopapular rash, confirmed to be caused by the vaccine strain rubella virus. She fully recovered. No other vaccine-associated illness was identified in the cohort after a median follow-up of 676 days. Conclusions MMR vaccine appears to be well tolerated in select HCT recipients when given between 300 and 729 days after transplant. An uncomplicated case of vaccine-associated rubella illness was seen after vaccination. Assessment of potential risks and benefits of MMR vaccination given within 2 years of HCT remains important.

Mumps in Vaccinated Children and Adolescents: 2007–2019

BACKGROUND Despite a &gt;99% reduction in US mumps cases after the introduction of mumps vaccine in 1967, outbreaks have occurred in schools and other settings involving vaccinated children and adolescents since 2006. METHODS We analyzed mumps cases reported by US health departments to the National Notifiable Diseases Surveillance System. We present the incidence and vaccination status of pediatric cases (age &lt;18 years) during 2007–2019 and describe demographic, clinical, and vaccination characteristics of pediatric cases reported during the most recent resurgence in 2015–2019. RESULTS During 2007–2019, 9172 pediatric cases were reported, accounting for a median of 32% of all cases reported each year (range: 13%–59%). A median of 87% (range: 81%–94%) of pediatric patients each year had previously received ≥1 measles, mumps, and rubella (MMR) vaccine dose. During 2015–2019, of 5461 pediatric cases reported, only 2% of those with known import status (74%) were associated with international travel. One percent of patients had complications and 2% were hospitalized. Among patients aged ≥1 year with known vaccination status (72%), 74% of 1- to 4-year-olds had received ≥1 MMR dose and 86% of 5- to 17-year-olds had received ≥2 MMR doses. Since 2016, pediatric mumps cases have been reported in most US states each year (range: 38–45 states). CONCLUSIONS Since 2007, one-third of US reported mumps cases occurred in children and adolescents, the majority of whom were vaccinated. Clinicians should suspect mumps in patients with parotitis or mumps complications, regardless of age, travel history, and vaccination status.

Rubella, German Measles

Rubella is caused by an RNA virus. Infection results mostly in few or no symptoms. Viremia and viral shedding start before a rash may be seen. German physicians were probably the first to describe rubella in the early 19th century, hence the name "German measles". A British physician reported an outbreak in a boys’ school in India in 1841. He used the word rubella, "little red", a Latin diminutive from ruber (red). Rubella is often indistinguishable from other viral exanthematous diseases, but palpable posterior auricular and suboccipital lymph nodes are almost pathognomonic. Rubella infection during pregnancy may result in cataract, heart disease and deafness in an infant, forming the key triad defining “congenital rubella syndrome”, CRS. Also, mental retardation is common. After birth, rubella is a mild disease with rare complications only. There is no treatment for rubella or CRS, but vaccination programs usually with MMR-vaccine maintaining high vaccine uptake over time can virtually eliminate rubella.

100. Safety Analysis of Live-Attenuated Measles, Mumps, Rubella Vaccine Among Hematopoietic Cell Transplant Recipients Vaccinated Within Two Years of Transplant

Background Measles, mumps and rubella (MMR) vaccine is a live-attenuated vaccine usually contraindicated within the first two years of hematopoietic cell transplant (HCT). During the 2019 measles outbreak at our center, the benefits of administering MMR vaccine within the first two years after HCT were weighed against the potential risks. Methods We conducted a retrospective review of patients who received MMR vaccination within two years of an autologous or allogeneic HCT. Patients’ demographics, date and type of HCT, underlying hematologic disease, type of immunosuppressive therapy and date of MMR vaccination were extracted from the electronic medical record. Adverse reactions that could be related to the vaccine were collected for up to 42 days post-vaccination and all hospitalizations and deaths following vaccination were reviewed. Results A total of 129 patients (75 autologous and 54 allogeneic HCT) were vaccinated between 300-729 days after HCT (median of 718 days). The median age at vaccination was 61 years old, 57% of the patients were male and 43% were on immunosuppressive therapy, 87% of whom were on maintenance therapy for multiple myeloma after auto-HCT. Seven patients (5%) had adverse reactions within 42 days of vaccination: six had respiratory tract infections (three with associated fever) and one had a rash leading to a brief hospitalization. This was a 37-year-old female who had an allogeneic HCT 542 days prior to MMR vaccination. She presented with a centrifugal maculopapular rash that was confirmed to be caused by the vaccine strain rubella virus (Fig 1). She fully recovered without sequalae. There was no other vaccine-associated illness identified in the cohort, after a median follow-up of 676 days. Conclusion MMR vaccine appears to be well tolerated in selected HCT recipients when given earlier than 2 years after transplant. No attributable severe outcomes or deaths were described. A mild uncomplicated case of vaccine-associated rubella illness was seen after vaccination. In the setting of a measles outbreak, assessment of potential risks and benefits of MMR vaccination given within two years of HCT remains important. Disclosures Stephen R. Walsh, MDCM, Janssen Vaccines (Scientific Research Study Investigator)Regeneron (Scientific Research Study Investigator)Sanofi Pasteur (Scientific Research Study Investigator) Matthew Cheng, MD, GEn1E Lifesciences (Advisor or Review Panel member)Kanvas Biosciences (Board Member, Shareholder)nplex biosciences (Advisor or Review Panel member) Sanjat Kanjilal, MD, MPH, GlaskoSmithKline (Advisor or Review Panel member) Nicolas C. Issa, MD, AiCuris (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)GSK (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)