A severe case of post-vaccination measles infection is described. Serology and molecular detection were consistent with measles virus infection and the phylogenetic analysis confirmed that the infection was due to the measles virus vaccine strain “Schwarz”, contained in the Priorix -Tetra® vaccine.

1. Measles virus infection by the vaccine strain in Athens, 2015: the importance of genotyping
E. Horefti (1), M. Emmanouil (1), V. Pogka (1), T. Liakopoulou (2), A. Mentis (1)
10th European Scientific Conference on Applied Infectious Disease Epidemiology, Stockholm, 28‐30 November 2016
1. Department of Public Health, Hellenic Pasteur Institute, Athens, Greece
2. Department of Paediatrics, IASO Children’s Hospital, Athens, Greece
Background
Although vaccine‐associated measles is a rare phenomenon, a few cases have been reported globally (Murti et al., 2013 and Xu et al., 2015) in
otherwise healthy individuals. MMRV vaccine may cause mild adverse effects such as febrile seizures in 1 in 1,250 children and low platelet
count that can cause a bleeding disorder in 1 in 40,000 children, but severe complications such as deafness, long‐term seizures and permanent
brain damage are classified as extremely rare (CDC, Vaccine Safety).
We report a case of infection by the measles vaccine strain in a 2‐year old boy with no history of underlying diseases, as well as of any type of
immunodeficiency. The boy was admitted to hospital nine days after being vaccinated with the live, attenuated vaccine against measles
(containing the attenuated Schwarz measles virus strain), rubella, mumps and varicella zoster virus Priorix ‐Tetra®. The clinical signs included
fever up to 40oC, generalized erythematous popular eruption, nasal congestion, pharyngitis and bilateral conjunctivitis. On day 5 of
hospitalization his general condition worsened as he developed acute respiratory distress (ARDS), stridor and tonsillitis. He was transferred to
the ICU where he remained for 20 days; upon release from the hospital the patient was in good condition.
Methods
Serum, whole blood and bronchial secretions samples were collected from the patient. Specific anti‐measles IgM antibodies were detected in the
serum by ELISA (Enzygnost ® Anti‐Measles Virus IgM). The bronchial secretions and the whole blood were tested for detection of varicella zoster
virus, Epstein‐Barr virus, cytomegalovirus with Real‐time PCR and for measles virus with rRT‐ PCR. Nested PCR and sequencing for measles
genotyping followed in the bronchial secretions sample. The sequence was aligned to the measles reference strains using the sequence alignment
editor BioEdit and the phylogenetic tree was constructed using the MEGA6 software.
Results
Th f d iti f th d t ti f I M tib di i t l i Th h l bl d ti f ll th i t t d
REAL – TIME PCR
(WHOLE BLOOD)
RESULT
V i ll Z t i N ti
The serum was found positive for the detection of IgM antibodies against measles virus. The whole blood was negative for all the viruses tested,
whereas the bronchial secretions sample was positive for the detection of measles virus and negative for the rest , as shown in Tables 1 and 2,
respectively. The virus genotype was determined as vaccine strain, genotype A, MVs/Athens.GR/10/2015 (Figure 1 ).
Table 1: Real‐time PCR results in the
whole blood sample.
Figure 1: The phylogenetic tree constructed that shows the relationship between the
strain isolated in our laboratory and other vaccine strains.
Varicella Zoster virus Negative
Cytomegalovirus Negative
Epstein‐Barr virus Negative
Adenoviruses Negative
Measles virus Negative
Table 2 : Real‐time PCR results in the
bronchial secretions sample.
REAL – TIME PCR
(BRONCHIAL
SECRETIONS)
RESULT
Varicella Zoster virus Negative
Cytomegalovirus Negative
Epstein‐Barr virus Negative
Adenoviruses Negative
p
Conclusion
We describe a severe case of post vaccination measles infection Serology and molecular detection were consistent with measles virus
Adenoviruses Negative
Measles virus Positive
According to the phylogenetic tree analysis, the measles strain isolated in our laboratory is closely related to Measles virus strain
Rouvax‐Schwarz nucleoprotein (N) mRNA and Measles virus vaccine strain Schwarz nucleoprotein gene , showing a 100% nucleotide identity.
We describe a severe case of post‐vaccination measles infection. Serology and molecular detection were consistent with measles virus
infection and the phylogenetic analysis confirmed that the infection was due to the measles virus vaccine strain “Schwarz”, contained in
the Priorix ‐Tetra® vaccine.
The measles vaccine‐associated infection is indistinguishable from the wild type and genotyping is a useful tool for the differentiation
between measles genotypes and, thus, the exclusion of a wild type infection. This is important for public health, as during measles
outbreaks the vaccine is provided in order to control the spread of the infection, a vaccine reaction may be falsely classified as a wild
type case. Also, as in our case, a quick and valid vaccine genotype determination excludes the possibility of an outbreak, maintaining
the accuracy of the measles surveillance system.