U.S. scientists develop mouse model to test Zika vaccines, drugs
admin • March 29, 2016 • 2579
Aedes aegypti mosquitoes are seen at the Laboratory of Entomology and Ecology of the Dengue Branch of the U.S. Centers for Disease Control and Prevention in San Juan, March 6, 2016. REUTERS/Alvin Baez
U.S. scientists have identified a genetically modified strain of mice that develop Zika, an important tool needed for testing vaccines and medicines to treat the virus that is rapidly spreading across the Americas and the Caribbean.
Early tests on the mice show the virus growing in the testes, offering clues about how a virus typically spread by mosquito bites can be transmitted sexually.
“We are going to do experiments to see if we can produce sexual transmission” in these mice, said Scott Weaver, a virologist at the University of Texas Medical Branch in Galveston who worked on the study published on Monday in the American Journal of Tropical Medicine and Hygiene.
Weaver said the Zika mouse model will provide a critical tool to allow companies and scientists to test vaccines and antiviral drugs against Zika, which has been linked with thousands of cases of microcephaly, a rare birth defect marked by unusually small head size and possible developmental problems.
Zika has not been proven to cause microcephaly, but strong evidence connecting Zika infections with microcephaly cases in Brazil prompted the World Health Organization to declare Zika a global health emergency on Feb. 1.
Normally, creating this kind of mouse model would take several months. But the urgency of the Zika outbreak called for rapid response, and the team put together the results in just three weeks, said Shannan Rossi, a UTMB virologist who led the study.
Normally, mice do not become sick from a Zika infection. The team tested the virus on several genetically altered mice that had weakened immune systems. The young mice quickly succumbed to the virus, becoming lethargic, losing weight and typically dying six days later.
Testing on the mice showed virus particles in many major organs, including high concentrations in the spleen, brain and testes.
While Weaver says there are limits to what mouse models can tell about human infections, they may at least provide some early clues that could be followed up in non-human primates, a more costly animal model that is a better predictor of human disease.
“The mouse will mainly be used to do the very earliest testing of vaccines or drugs where the mechanism of disease doesn’t have to be a perfect model to what happens in humans,” Weaver said.
Brazil has confirmed more than 900 microcephaly cases and considers most related to Zika infections in the mothers. It is investigating nearly 4,300 additional suspected cases of microcephaly.
(Reporting by Julie Steenhuysen; Editing by Dan Grebler)
President Rodrigo Duterte said the Philippines will purchase the cheapest vaccine for the coronavirus disease (COVID-19).
During his public address Monday evening (September 7), the President said he is optimistic that a vaccine will be available this September.
“I think it’s Moderna. It’s a US company. I think they are ready by September,” he said.
Aside from China, Russia also offered their COVID-19 vaccine to the Philippines.
The President added that the government will choose the company that will offer the cheapest vaccine since the country has limited funds.
“Pare-pareho lang naman iyan. Parehong germs iyan. Kung sino lang ang nauna magbigay sa’tin na mura, doon tayo pupunta, kasi they know that we do not have enough money. Kung mahal masyado, we will go for the less expensive ones,” Duterte said. AAC (with reports from Rosalie Coz)
GENEVA, Switzerland — The World Health Organization (WHO) announced on Tuesday (February 11) that it takes time to develop a vaccine against the novel coronavirus now named COVID-19.
However, the international health body hopes to have an effective vaccine within 18 months.
“The development of vaccines and therapeutics is one important part of the research agenda. But it’s not only one part. They will take time to develop — but in the meantime, we are not defenseless,” said WHO Chief Dr. Tedros Adhanom Ghebreyesus during a press conference at the agency’s headquarters.
“The first vaccine could be ready in 18 months, so we have to do everything today using the available weapons to fight this virus, while preparing for the long-term,” he added.
He noted, however, that even though WHO already named the new virus as COVID-19, there are still many unknown factors that are preventing scientists from finding an exact cure.
“It’s hard to believe that just two months ago, this virus – which has come to captivate the attention of media, financial markets and political leaders – was completely unknown to us,” Tedros said.
“To defeat this outbreak, we need answers to all those questions and more,” he added.
During briefing, the official labeled the disease as “public enemy number one” that poses a global threat, despite most of the cases being confined in mainland China.
“With 99 percent of cases in China, this remains very much an emergency for that country, but one that holds a very grave threat for the rest of the world,” the official noted.
So far, Dr. Tedros said, WHO is working with countries to strengthen laboratory capacity around the world, ensuring enough supplies of testing kits and protective equipment for health workers and training them to help prevent further spread of COVID-19.
What’s important for now, he added, is for every individual to become part of the preventive strategy.
At least, he explained, individuals should be sensitive not only of his or her own health but also of the people around.
“And we’re keeping the public informed about what everyone can do to protect their own health and that of others,” he said.
“That’s why reaching out to the public directly and telling them the precautions they should take,” he added.
Dr. Tedros reiterated the basic preventive measures that people should religiously practice while there remains no cure for the coronavirus disease.
“Clean your hands regularly, either with alcohol-based rub or soap and water. Keep your distance from someone who is coughing or sneezing. And when you cough or sneeze, cover your mouth and nose with a tissue or your elbow,” he concluded.
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