A yellow fever outbreak in Brazil that began in December of 2016 has continued to grow in this and several other South American countries, leading to shortages of the conventional vaccine for the virus for Americans looking to travel Brazil and other affected areas. Now an alternative vaccine available in other countries has received approval in the United States, and can be found in vaccination clinics around the country.
Yellow fever is a mosquito-borne virus which has caused outbreaks in North America centuries ago and is now mostly isolated to tropical and subtropical parts of Africa and South America. Aedes and Haemagogus mosquitos transmit the virus from infected humans and non-human primates. Most people who become infected with yellow fever do not present with symptoms or only exhibit mild illness. When symptoms do occur, they typically develop within 3 to 6 days of infection and can include fever, severe headache, chills, back and body aches, and nausea. While symptoms clear in most infected individuals, infection can become more severe in about 15% of cases after a brief remission period. This can result in high fever, jaundice, bleeding, and even organ failure. Up to half of those who develop severe yellow fever symptoms die from the virus.
In Brazil, a large outbreak of yellow fever has continued to grow. According to a recent situation summary from the Pan American Health Organization (PAHO), Brazil has reported 3,192 suspected cases since December. Of those, health officials have confirmed 758 cases, discarded 1812, and is continuing to investigate 622 cases. Brazil’s Ministry of Health has reported 426 deaths linked to the outbreak, making it a 34% fatality rate among confirmed cases. In addition, the country has reported 3,660 deaths in non-human primates since the start of the outbreak, with yellow fever confirmed to be the cause of 565 deaths, and 1467 deaths still under investigation.
While the outbreak has largely remained in low population areas of Brazil, the recent PAHO update notes that health officials have directed available reserves of the yellow fever vaccine, YF-VAX, to preventing these outbreaks from spreading into more populated, urban areas. In recent months 24.5 million doses of YF-VAX have gone to a selective vaccination strategy in more than 1,000 Brazilian municipalities. As a result, 285 municipalities in the country have achieved more than 95% vaccination coverage, while 375 municipalities have achieved between 74% and 94.9% coverage. However, this outbreak in Brazil coupled with the ongoing outbreak in Angola have led to the depletion of the vaccine supply. In fact, the Centers for Disease Control and Prevention (CDC) recently stated that YF-VAX maker Sanofi Pasteur announced that the vaccine will be unavailable until mid-2018. For American travelers visiting countries requiring yellow fever vaccination, Sanofi Pasteur has recently received approval from the US Food and Drug Administration to distribute Stamaril, an alternative vaccine that offers active immunization against the virus in a single-dose injection. Stamaril is already available in more than 70 countries. Now, in the United States the vaccine has been FDA-approved through an Expanded Access Investigational New Drug Application, meaning that it is still considered investigational. Due to this limitation, “Sanofi Pasteur can support only a limited number of sites,” including several US vaccination clinics; however, the pharmaceutical company is working with the CDC to expand distribution of and access to the vaccine.
The CDC recommends one dose of the yellow fever vaccine for those ages 9 months or older who are traveling to areas experiencing outbreaks of the virus, or to countries in sub-Saharan Africa and tropical South America where the virus is endemic and intermittently epidemic. Those travelling to Brazil or other countries with active yellow fever outbreaks should receive the Stamaril vaccineat least 10 days before entering an affected area to ensure they’ve receive protective immunity. The World Health Organization Advisory Group of Experts on Immunization notes that one dose of the vaccine offers lifelong protection from the yellow fever virus.
Source
Yellow fever is a mosquito-borne virus which has caused outbreaks in North America centuries ago and is now mostly isolated to tropical and subtropical parts of Africa and South America. Aedes and Haemagogus mosquitos transmit the virus from infected humans and non-human primates. Most people who become infected with yellow fever do not present with symptoms or only exhibit mild illness. When symptoms do occur, they typically develop within 3 to 6 days of infection and can include fever, severe headache, chills, back and body aches, and nausea. While symptoms clear in most infected individuals, infection can become more severe in about 15% of cases after a brief remission period. This can result in high fever, jaundice, bleeding, and even organ failure. Up to half of those who develop severe yellow fever symptoms die from the virus.
In Brazil, a large outbreak of yellow fever has continued to grow. According to a recent situation summary from the Pan American Health Organization (PAHO), Brazil has reported 3,192 suspected cases since December. Of those, health officials have confirmed 758 cases, discarded 1812, and is continuing to investigate 622 cases. Brazil’s Ministry of Health has reported 426 deaths linked to the outbreak, making it a 34% fatality rate among confirmed cases. In addition, the country has reported 3,660 deaths in non-human primates since the start of the outbreak, with yellow fever confirmed to be the cause of 565 deaths, and 1467 deaths still under investigation.
While the outbreak has largely remained in low population areas of Brazil, the recent PAHO update notes that health officials have directed available reserves of the yellow fever vaccine, YF-VAX, to preventing these outbreaks from spreading into more populated, urban areas. In recent months 24.5 million doses of YF-VAX have gone to a selective vaccination strategy in more than 1,000 Brazilian municipalities. As a result, 285 municipalities in the country have achieved more than 95% vaccination coverage, while 375 municipalities have achieved between 74% and 94.9% coverage. However, this outbreak in Brazil coupled with the ongoing outbreak in Angola have led to the depletion of the vaccine supply. In fact, the Centers for Disease Control and Prevention (CDC) recently stated that YF-VAX maker Sanofi Pasteur announced that the vaccine will be unavailable until mid-2018. For American travelers visiting countries requiring yellow fever vaccination, Sanofi Pasteur has recently received approval from the US Food and Drug Administration to distribute Stamaril, an alternative vaccine that offers active immunization against the virus in a single-dose injection. Stamaril is already available in more than 70 countries. Now, in the United States the vaccine has been FDA-approved through an Expanded Access Investigational New Drug Application, meaning that it is still considered investigational. Due to this limitation, “Sanofi Pasteur can support only a limited number of sites,” including several US vaccination clinics; however, the pharmaceutical company is working with the CDC to expand distribution of and access to the vaccine.
The CDC recommends one dose of the yellow fever vaccine for those ages 9 months or older who are traveling to areas experiencing outbreaks of the virus, or to countries in sub-Saharan Africa and tropical South America where the virus is endemic and intermittently epidemic. Those travelling to Brazil or other countries with active yellow fever outbreaks should receive the Stamaril vaccineat least 10 days before entering an affected area to ensure they’ve receive protective immunity. The World Health Organization Advisory Group of Experts on Immunization notes that one dose of the vaccine offers lifelong protection from the yellow fever virus.
Source
No comments:
Post a Comment