Investigation of an outbreak of measles: Failure to vaccinate or vaccine failure in a community of predominantly fishermen in Kerala

Maternally transmitted anti-measles antibodies, and susceptibility to disease among infants in Chandigarh, India: A prospective birth cohort study

Prior to the age of measles vaccination, infants are believed to be protected against measles by passively transferred maternal antibodies. However, the quantity and quality of such protection have not been well established in the Indian setting. We undertook this study to characterize the transfer and decline in maternal anti-measles antibodies among infants, and determine their susceptibility to measles. In this population-based, birth-cohort study, we enrolled pregnant women and their newborn infants, from a catchment area of 30 Anganwadis in Chandigarh, India. We collected maternal blood at delivery, and infant blood samples at birth, and 3, 6, and 9 months of age. Anti-measles IgG antibodies were measured using quantitative ELISA. We assessed antibody decline using log-linear models. In total, 428 mother-infant dyads were enrolled, and data from 413 dyads were analyzed. At birth, 91.5% (95% CI: 88.8, 94.2) of infants had protective antibody levels, which declined to 26.3% (95% CI: 21.0%, 31.9) at 3 months, 3.4% (95% CI: 0.9, 5.9) at 6 months, and 2.1% (95% CI: 0.1, 4.1) at 9 months. Younger mothers transferred lower levels of antibodies to their infants. We concluded that the majority of infants are susceptible to measles as early as three months of age, much earlier than their eligibility to receive measles vaccination.

Measles Outbreak Investigation in Guradamole District of Bale Zone, South Eastern Ethiopia, 2021

Background

Method

Results

Conclusion

Epidemiology of measles cases, vaccine effectiveness, and performance towards measles elimination in The Gambia

Introduction

In 2011, member states of the World Health Organization (WHO) Africa Regional Office (AFRO) resolved to eliminate Measles by 2020. Our study aims to assess The Gambia’s progress towards the set AFRO measles elimination target and highlight surveillance and immunisation gaps to better inform future measles prevention strategies.

Material and methods

A retrospective review of measles surveillance data for the period 2011–2019, was extracted from The Gambia case-based measles surveillance database. WHO—UNICEF national coverage estimates were used for estimating national level MCV coverage. Measles post campaign coverage survey coverage estimates were used to estimate national measles campaign coverage.

Results

One hundred and twenty-five of the 863 reported suspected cases were laboratory confirmed as measles cases. More than half (53.6%) of the confirmed cases have unknown vaccination status, 24% of cases were vaccinated, 52.8% of cases occurred among males, and 72.8% cases were among urban residents. The incidence of measles cases per million population was lowest (0) in 2011–2012 and highest in 2015 and 2016 (31 and 23 respectively). The indicator for surveillance sensitivity was met in all years except in 2016 and 2019. Children aged 5–9 years (Incidence Rate Ratio—IRR = 0.6) and residents of Central River region (IRR = 0.21) had lower measles risk whilst unvaccinated (Adjusted IRR = 5.95) and those with unknown vaccination status (IRR 2.21) had higher measles risk. Vaccine effectiveness was 89.5%.

Conclusion

The Gambia’s quest to attain measles elimination status by 2020 has registered significant success but it is unlikely that all target indicators will be met. Vaccination has been very effective in preventing cases. There is variation in measles risk by health region, and it will be important to take it into account when designing prevention and control strategies. The quality of case investigations should be improved to enhance the quality of surveillance for decision making.

Factors associated with and screening models of national immunization programme vaccine series completion among preschool children in Fujian Province, south-eastern China

BACKGROUND

An effective method for the rapid identification of vulnerable preschool children at risk of not completing the national immunization programme (NIP) vaccine series in China is still lacking.

METHODS

A cross-sectional study involving 772 preschool children born between September 1 2009 and August 31, 2011 was conducted in 2015 in Fujian Province, south-eastern China. The data were collected by face-to-face interviews with the parents or guardians of the children using a standard questionnaire.

RESULTS

Children who received the first dose of a hepatitis B vaccine (HepB) less than 24h after birth and those who received one or more doses of surrogate for-fee vaccines (SFVs) were more likely to complete the NIP vaccine series with adjusted odds ratios (ORs) of 3.12 (95% confidence interval [CI]: 1.19-8.23) and 4.74 (1.41-15.90), respectively. The cut-off value of the prediction score for the completion of the NIP vaccine series was 92.5%, and the sensitivity, specificity, and positive and negative predictive values were 87.5%, 47.1%, 11.4% and 98.0%, respectively.

CONCLUSIONS

The receipt of a timely first dose of HepB and one or more doses of SFVs were associated with and good predictors of NIP vaccine series completion by preschool children in Fujian, China.