BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: outbreak

There Are More Viruses On Earth Than Stars In The Universe. Why do only some infect us?

Scientists have estimated that there are 10 nonillion (10 to the 31st power) viruses currently on our planet. They are everywhere. Many viruses are beneficial for their host, many inflict no harm, but why do so few viruses affect us and even fewer severely affect us? The short answer: “These pathogens are extraordinarily picky about the cells they infect, and only an infinitesimally small fraction of the viruses that surround us actually pose any threat to humans” says virologist Sara Sawyer.

Understanding how certain viruses affect humans is crucial for protecting and preventing future outbreaks. COVID-19, the most recent outbreak that experienced a “spillover event,” was initially spread through interactions with an animal that is a “non-human primate”. This is called zoonosis. Multiple outbreaks have been introduced this way, but not can be started this way. Pathogens can also enter through cuts, scrapes, mosquitoes, ticks, etc. Once a virus has entered, it needs to find a way to get inside the cells and replicate. To do this, it must first attach to the surface of a host cell and then inject its genetic material (RNA) into the cell. The virus’s genetic material then takes over the machinery of the host cell, using it to replicate itself and produce new viruses. Viruses with a lot of genetic flexibility, and particularly those that encode their genomes as RNA rather than DNA, are well-suited to crossing the species divide. The majority of pathogens that have infected the human population in recent decades have been RNA viruses, including Ebola, SARS, MERS, Zika, several influenza viruses, and SARS-CoV-2. The more lethal viruses were found to have been hiding in their hosts for longer periods of time before showing any symptoms. This would allow it to replicate and spread to new species.

 

Coronavirus. SARS-CoV-2

So the answer is; that a virus has to be incredibly sophisticated for it to cause harm to a human, pandemics are so rare because of precautionary measures such as vaccines, healthcare, and proper sanitation. The continuous study of viruses and their behavior is an important task for the human population and its future as current viruses are continuously mutating and developing with each given day.

 

Pneumonia Outbreak in China: What You Should Know.

Weeks before the starting of 2020, a mysterious case of pneumonia seemingly caused by a contagious virus broke in Wuhan, China. The outbreak occurred in a local fish market which sold the meat of various exotic animals. The fascinating thing about this strange case is that scientists were unable to link it to previously known about pathogens such as SARS, MERS, or influenza. The true culprit of the spreading infection remained a mystery until scientists were able to analyze the genetic code of what they believed was the virus causing the panic.

A New Coronavirus

On January 10th the DNA Genome of the virus was recorded and scientists were finally able to identify the virus as a pathogen known as a “coronavirus“. Coronaviruses are fairly common and spread all types of illnesses from the common cold to severe acute respiratory syndrome or SARS. China and the world at large have actually gotten pretty familiar with handling these types of diseases as a global outbreak of SARS that originated in China occurred in 2003, barely a decade before the emergence of this new coronavirus. Thanks to this SARS outbreak, which infected 8,000 people and killed nearly 800, China has since had a very cautionary culture when it comes to medical issues. It is not uncommon to see people wearing medical masks regularly in public in order to prevent contamination in the highly populated areas of China. One can assume that this culture in China has helped with the current outbreak’s speedy treatment.

Effects and Outcomes

As a result of the spreading of the virus in the seafood supermarket, 59 patients were brought to the hospital, seven of which were in critical condition. It is known that coronaviruses all come from animal to human transmission so it is no surprise that the virus would appear so rapidly in an area where many humans interact with many animals. Since the outbreak, this market has been closed as of January 1st to few’s surprise. However, it is sad to say that the virus has claimed the life of a 61 year old man how seemingly was weak from many other ailments from his old age. While the newfound coronavirus has been proven to be deadly, many medical professionals and The WHO (World Health Organization) say there should be no cause for great concern as the outbreak has seemingly been contained since late December and there are no true prospects of it becoming a world like epidemic like SARS in 2003. Nonetheless, this recent case of pathological disease spreading serves as a reminder of the deadly forces we must all be careful of every day.

A Cure for Zika? Scientists successfully test a DNA-based Zika Vaccine

The Zika virus, widely known for its 2015 Latin and North America outbreak, is a mosquito-borne and transmitted virus that develops neurological complications and birth-defects in those infected. The Zika virus is able to be transmitted from a pregnant woman to her fetus, causing microcephaly– abnormal development of the brain. Currently, there exists no vaccine that would fully treat the virus, however, a solution may be in the works.

(Photo from Wikipedia Commons)

David B. Weiner, Ph.D., an executive vice president of The Wistar Institute and a developer of the Zika vaccine notes that, “Synthetic DNA vaccines are an ideal approach for emerging infectious diseases like Zika”. Synthetic DNA vaccines are vaccines with genetically engineered DNA. They work in the same way as regular vaccines, inciting cells to produce specific antigens for immunological responses. Synthetic DNA vaccines can also have potential benefits over traditional vaccines, including a higher predictability, stability, and ability to be manufactured and distributed safely and rapidly.

The current Zika vaccine in development, GLS-5700, houses multiple strains of genes with DNA instructions that tell a hosts’ cells how to react and fight off a Zika virus antigen. In late 2016, researchers tested the vaccine on 40 participants. Two groups of 20 received different does of the vaccine at zero, four, and twelve week intervals. At the end of the experiment, researchers found that all participants had developed Zika-specific antibodies and 80 percent of the participants developed neutralizing antibodies against the Zika virus.

Zika 2015-2016 Outbreak (Photo from Wikipedia Commons)

Although rare in the United States, Zika continues to threaten millions living in South and Central America. Despite being in its last stages of development, GLS-5700 and other Synthetic DNA vaccines are still prohibited from being used in the United States- although this may change with the introduction of the Zika vaccine. The future of Synthetic DNA vaccines and viral disease prevention lies in the success of the GLS-5700.

 

 

 

 

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