Although Zika and dengue are considered different virus “species,” they are so closely related that the immune system treats Zika just like another version of dengue, report researchers. Their latest study shows that pre-existing immunity to dengue virus modulates the magnitude and breadth of the immune system’s T cell response to Zika.
In February 2017, a new A(H7N9) virus -- indicating high pathogenicity in poultry -- was detected in three patients connected to Guangdong, China, as well as in environmental and poultry samples. This is an important development to be monitored, however, ECDC's updated rapid risk assessment concluded that the risk of the disease spreading within Europe via humans is still considered low, as there is no evidence of sustained human-to-human transmission.
Older adults are at high risk for serious complications from flu and account for a majority of flu-related deaths and hospitalizations. H3N2 influenza viruses typically hit this age group particularly hard and have been associated with higher mortality than infections by H1N1 or influenza B viruses. During the 2012-2013 season, when H3N2 viruses were dominant, high-dose flu vaccine was 36 percent more effective at preventing deaths in the Medicare beneficiaries studied, compared to standard-dose vaccine.