Two Case Studies of Modified Measles in Vaccinated Physicians Exposed to Primary Measles Cases: High Risk of Infection But Low Risk of Transmission

Abstract

In 2009, measles outbreaks in Pennsylvania and Virginia resulted in the exposure and apparent infection of 2 physicians, both of whom had a documented history of vaccination with >2 doses of measles-mumps-rubella vaccine. These physicians were suspected of having been infected with measles after treating patients who subsequently received a diagnosis of measles. The clinical presentation was nonclassical in regard to progression, duration, and severity. It is hypothesized that the 2 physicians mounted vigorous secondary immune responses typified by high avidity measles immunoglobulin G antibody and remarkably high neutralizing titers in response to intense and prolonged exposure to a primary measles case patient. Both of the physicians continued to see patients, because neither considered that they could have measles. Despite surveillance for cases among contacts, including unvaccinated persons, no additional cases were identified.

A systematic review of tetanus in individuals with previous tetanus toxoid immunization

“…This is in keeping with an attenuation of clinical severity in immunized hosts that is recognized in other vaccine-preventable diseases (24)(25)(26).…”

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

“…38 , 39 Their ability to transmit virus, however, is thought to be greatly diminished, as subsequent spread of measles from a person with prior immunity has rarely been documented. 38 , 40 , 41 Because primary versus secondary vaccine failure cases cannot be readily distinguished without specialized testing and cases with a past immunologic response to measles might be contagious, 38 any person with confirmed measles, regardless of vaccination status, is recommended to be isolated for the duration of the infectious period. 1-4 (Of note, transmission from previously immune individuals is of great interest and has important implications for sustaining elimination; studying such transmission requires clinical specimens and specialized laboratory investigations.…”

The Largest Measles Outbreak, Including 38 Modified Measles and 22 Typical Measles Cases in Its Elimination Era in Yamagata, Japan, 2017

“…3). Moreover, we considered that the two associates developing M-Me were not related to the measles transmission because preceding studies indicated that the transmissibility of M-Me was low (12,13).…”

“…These patients could be sources of transmission even though the risk is low (12)(13)(14). In order to prevent measles transmission and outbreaks, cases of M-Me should be adequately diagnosed, as should cases of T-Me.…”