RIO DE JANEIRO – Two people died in the Brazilian state of Sao Paulo from negative reactions to yellow fever vaccinations at a time when thousands of people are jamming into medical centers to be immunized, in view of the big increase in deaths from the disease, officials announced on Friday.
As Municipal Health Secretary Wilson Pollara stated on the G1 online news site, the victims were two people with “low immunity,” a woman age 76 and a man whose identity has not yet been revealed.
The vaccine is currently recommended for those between the ages of nine months and 59 years. People older than that need a medical exam to find out the state of their immunological system and to see if they have a high risk of being contaminated by the disease or not.
Dr.Expedito Luna, an epidemiologist and professor with the Tropical Medicine Institute at the University of Sao Paulo, said on G1 that since the year 2000 it has been identified in Brazil and other places in the world that a small proportion of those who are vaccinated could develop a serious case of the yellow fever itself.
“In the study of those rare cases with adverse reactions, it turned out to be common among those over age 60, with diseases of the thymus and autoimmune system, which led to a greater restriction of administering the vaccine in those cases,” the doctor said.
Specialists categorize two types of yellow fever, which are differentiated by the infecting mosquito: one is the “wild” kind transmitted by the Haemagogus and the Sabethes species, which mainly attack the macaque – and the “urban” type, which transmits the Aedes aegypti, also the vector of dengue, Zika and Chikungunya.
For several years, however, not one case of yellow fever caused by the urban type has been recorded.
Southeast Brazil, chiefly the states of Minas Gerais, Sao Paulo and Rio de Janeiro, for several weeks have seen an outbreak of this infectious viral disease that is transmitted by mosquito bites and has caused at least 15 deaths.