Neutralizing Antibody Response to Genotypically Diverse Measles Viruses in Clinically Suspected Measles Cases.

The neutralizing antibody (Nt-Ab) response to vaccine and wild-type measles viruses (MeV) was studied in suspected measles cases reported during the years 2012-2016. The neutralization activity against MeV A, D4 and D8 genotypes was studied on sera (Panel A; n = 68 (measles-immunized) and Panel B; n = 50 (unvaccinated)) that were either laboratory confirmed or not confirmed by the presence of IgM antibodies. Additionally, the Nt-Ab response in Panel A was measured against the MeV vaccine and four wild-type viruses. Neutralization results were compared using homology modeling and molecular dynamics simulation (MDS) of MeV-hemagglutinin (H) and fusion (F) proteins. Overall, the Nt-Ab titres for MeV-A were found to be significantly lower than MeV-D4 and MeV-D8 viruses for Panel A. No major difference was noted in Nt-Ab titres between MeV-D8 viruses (Jamnagar and New Delhi), whereas MeV-D4 (Sindhudurg and Bagalkot (BGK) viruses) showed significant differences between Nt-Ab titres for Panel B. Interestingly, the substitutions observed in epitopes of H-protein, L249P and G316A are observed to be unique to MeV-BGK. MDS of H-protein revealed significant fluctuations in neutralizing epitopes due to L249P substitution. The majority of the clinically suspected cases showed Nt-Abs to MeV wild-types. Higher IgG antibody avidity and Nt-Ab titres were noted in IgM-negatives than in IgM-positives cases, indicating reinfection or breakthrough. MDS revealed reduced neutralization due to decreased conformational flexibility in the H-epitope.

Epidemiological characteristics of measles cases with immunization history of MCV in Liaoning in 2014-2021 / 公共卫生与预防医学

Objective To analyze the epidemiological characteristics of measles cases with immunization history of measles-containing vaccine (MCV), and to provide a basis for improving measles prevention and control measures. Methods Data were collected through the measles surveillance system and the immunization program information management system. Data were analyzed by descriptive epidemiological methods. Results A total of 9 164 cases of measles were reported in Liaoning Province during 2014-2021, of which the cases of measles with immunization history of 1 dose MCV accounted for 5.64%, and ≥ 2 doses accounted for 3.60%. There was a statistically significant difference in the immunization proportion among different years (χ2=184.534, P2=109.448, P2=4.147, P<0.05). The onset time of most cases was over 2 weeks after the last dose of MCV vaccination, accounting for 82.06%. The incidence rates of fever, cough, catarrh symptoms, conjunctivitis, lymph node enlargement and articular pain were all significantly lower in the cases with immunization history than those in the patients without a history of MCV immunization (P<0.05). Conclusion The cases with immunization history account for a certain proportion in measles cases, mainly secondary vaccination failure. The incidence rate of fever, cough, catarrhal symptoms, conjunctivitis, Koch's patches, lymphadenopathy, joint pain, and other clinical symptoms in measles patients with a history of MCV immunization is lower than that in patients without immunization history. Inoculation of MCV is of great significance in relieving clinical symptoms. It is necessary to inoculate two doses of MCV in time for measles prevention and control.

Rubella IgM epidemiology in the pre-rubella vaccination era in Uganda.

BACKGROUND: Control of Rubella and Congenital Rubella Syndrome using vaccination has shown great success in the America's. Uganda is due to introduce the Rubella vaccine however the magnitude of transmission is not well documented. Therefore this study was done to determine IgM sero-prevalance for Rubella in order to help monitor vaccine effectiveness post introduction of the vaccine in routine vaccination programme. METHODS: A retrospective review of suspected measles cases data for the reporting period January 2007 to December 2016 in Uganda was Done. rubella IgM testing was done on 15,296 of the cases and the data was analyzed using STATA version 13. RESULTS: In total 15,296 cases were tested and 4255 (27.8%) tested positive and among females aged 15-49 years 88 out of 322 (27%) tested positive. The age distribution range was 0-80 years, rubella IgM positivity was reported in all the 15 regions of Uganda and throughout the ten year period in every month. Age group 5-15 years had OR 2.5 p-value < 0.001 of being rubella IgM positive compared to age < 5 years and testing measles IgM negative OR 6.3 p-value < 0.001. CONCLUSION: Rubella is endemic in Uganda and although rubella IgM positivity is highest in the age 5-15 years even the younger, older and women of reprodutive age are affected. This means the risk of Congenital Rubella Syndrome is high hence the need to introduce the rubella vaccine for infants and pregnant mothers and continued surveillance to enhance its control.

Reported measles cases, measles-related deaths and measles vaccination coverage in Myanmar from 2014 to 2018.

BACKGROUND: There is a global resurgence of measles, consequent upon worldwide stagnating measles vaccination coverage. The study aim was to document trends and characteristics of reported cases of measles, measles-related deaths, and measles vaccination coverage (MCV1-first dose of measles-containing vaccine and MCV2-second dose of measles-containing vaccine) at national and sub-national level in Myanmar over a five year period between 2014 and 2018. METHODS: This was a descriptive study using routine data collected and submitted to the Expanded Programme on Immunization. RESULTS: Between 2014 and 2018, there were 2673 measles cases of which 2272 (85%) occurred in 2017 and 2018. Five adjacent regions in lower Myanmar were the most affected: in 2017 and 2018, these regions reported 1647 (73%) of the 2272 measles cases in the country. Overall, 73% of measles cases were laboratory confirmed, 21% were epidemiologically linked, and 6% were clinically compatible (clinical diagnosis only), with more laboratory confirmed cases in recent years. Annual measles-related deaths were either zero or one except in 2016 when there were 21 deaths, all occurring in one remote village. In the recent years, the most commonly affected age groups were 0-8 months, 9 months to 4 years, and ≥ 15 years. Among 1907 measles cases with known vaccination status, only 22% had been vaccinated and 70% of those had only received one dose of vaccine. Annual MCV1 coverage nationally varied from 83 to 93% while annual MCV2 coverage nationally varied from 78 to 87%, with no clear trends over the years. Between 2014 and 2018, a high proportion of the 330 townships had MCV coverage < 95%. Over 80% of measles cases were reported from townships that had MCV coverage < 95%. CONCLUSION: There have been a large number of measles cases in recent years associated with sub-optimal measles vaccine coverage. Myanmar has already conducted supplemental immunization activities in October and November, 2019. Myanmar also needs to improve routine immunization services and targeted responses to measles outbreaks.

Test result analysis on IgM antibody determination in 367 cases of suspected measles in Changshu City / 上海预防医学

[Objective]To analyze the IgM antibody detection results for suspected cases of measles from2013 to 2016 in Changshu City, in order to provide basis for formulation of strategies of prevention and control of measles. [Methods] The serum samples of 367 suspected measles cases were detected for measles IgM by enzyme linked immunosorbent (ELISA) methods. [Results] The serum samples of 246 suspected measles cases were measles IgM positive, the positive rate being 67.03％. The number of cases of measles obviously increased in 2015 and 2016, and the paroxysm of measles tended to occur in the population of low and older ages, showing dipolar pattern. The differences of IgM antibody between different age groups had statistical significance (χ2= 27.03, P < 0.01). Measles broke out mainly from March to August, when there were obvious differences on the positivity of IgM antibody detected at different times after rash occurrence (χ2= 13.62, P < 0.01). [Conclusion] Measles immunization should be enhanced and measles vaccination replenished properly. It is also necessary to raise the rate of measles vaccination among children of suitable age within the jurisdiction. Strengthen monitoring on measles in floating population, enhance vaccine replanting and revaccination of measles in floating population, adult and fertile women and enhance immune level in high incidence population.