Measles Outbreak Among Previously Immunized Healthcare Workers, the Netherlands, 2014

Abstract

Measles occurred in 6 twice-vaccinated HCWs, despite 2 having adequate pre-exposure neutralizing antibodies. None of the twice-vaccinated cases had severe measles, and none had onward transmission, consistent with laboratory findings suggesting a secondary immune response. Improving 2-dose MMR coverage among HCWs would have likely reduced the size of this outbreak.

Measles outbreak after 12 years without endemic transmission, Portugal, February to May 2017

“…However, immunity gaps persist, with vulnerable population pockets [3,14,15]. We found a relatively large proportion of measles cases in vaccinated individuals and this has also been reported in other outbreaks [16-18]. This situation is expected in highly vaccinated communities and might be explained by the fact that MMR is not 100% effective, with around 7.5% and 5.0% non-respondents to the first and second doses, respectively [19].…”

Public health responses during measles outbreaks in elimination settings: Strategies and challenges

“…Use of oral fluid testing for seroprevalence studies 98 and for diagnostic and genotyping purposes 99–104 has proven valuable in a several European countries over the last decade. Collection of oral fluid specimens is less invasive than collection of serum and self-collection of oral fluid is possible.…”

Measles outbreak in a tertiary level hospital, Porto, Portugal, 2018: challenges in the post-elimination era

“…This feature has also been documented in other outbreaks [9,15]. The high frequency of cases among vaccinated people, likely due to waning vaccine-derived immunity [15] in a situation where natural boosting is taking place to a very limited extent, points towards the need to further investigate this issue to recommend new approaches. This is especially important for populations that are at a higher risk of being exposed to diseases, such as HCW, and spreading disease to individuals in a vulnerable situation, such as patients.…”

“…According to the National Plan for Measles Elimination [14], HCW are highly recommended to receive two doses of MMR vaccine or documented evidence of measles infection, considering they are at a higher risk of exposure to the virus. Nevertheless, we are seeing outbreaks occurring that encompass healthcare settings [9,15]. The frequency of cases among HCW directs attention to the need of considering interventions to ensure this group is well protected, including vaccination and infection control and prevention measures.…”