Updates of safety information on the known and rare risk of encephalitis with varicella vaccines

Following a review of all data regarding a very rare risk of encephalitis associated with varicella vaccines, which was necessitated by a new reported case, the EMA has updated the information regarding the severity of this condition in all vaccines containing the varicella component, providing further details on this known and very rare adverse event. These vaccines remain contraindicated in people with conditions that reduce the immune system's response, and no further measures are necessary.

Clozapine: New rules for blood monitoring

The PRAC has updated recommendations for blood monitoring in patients taking clozapine, a medicine indicated for resistant schizophrenia and psychotic disorders in Parkinson's disease.  . The risk of neutropenia (low white blood cell count) is higher in the first year; therefore, after 12 months the check-up may be less frequent (every 12 weeks, then annually after 2 years). It is recommended to check only the neutrophil count (which is a specific type of white blood cell), not the total white blood cell count.
The new indications will be updated in the leaflets of clozapine medicines and healthcare professionals will be informed with an important safety note.

Valproate and risk of neurodevelopmental disorders in children born to exposed fathers: data review is ongoing

The PRAC is evaluating new data on the risk of neurodevelopmental disorders (such as autism or ADHD) in children of fathers treated with valproate. A recent Danish study did not confirm this risk, unlike previous studies. The committee will investigate the differences between the studies to decide on possible updates.

New information on the Chikungunya virus vaccine

The EMA's safety committee (PRAC) has completed its review of the Ixchiq chikungunya vaccine. The temporary suspension of vaccination in people aged 65 and over has been lifted, but it has been established that the vaccine should only be used in cases of significant risk of chikungunya and after careful medical evaluation, especially in relation to the presence of other conditions.
Please note that the Ixchiq vaccine is not available in Italy. In the EU/EEA, the vaccine is available in Austria, Belgium, Denmark, Finland, France, Germany, Luxembourg, the Netherlands, Norway, and Sweden.

Published on: 11 July 2025