Saturday, September 26, 2020

Human semen can host different viruses

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What is semen?
Semen is a semi gelateneous fluid that is emitted from male reproductive tract and that contain spermatozoa/sperms in suspension of seminal fluids, which are capable of fertilizing female egg. Seminal fluids keep the sperm viable.

Can Viruses live in Semen?
It may seem strange, but yes, the viruses can live in semen. The question now is how many viruses can live in semen.
It’s more than what you might be thinking right now. At least 27 viruses can live in semen, and the number could be even more.

The study was recently conducted to find more  about human semen and the possibility of other viruses in human semen.
The researchers worked very hard in the process of finding out the possibility of other viruses. They reviewed 3,800 papers that were related to viruses and semen.

The findings from the research concluded that human semen is a safe haven for more than dozens of viruses. Unfortunately, these viruses often top the list of the world’s worst diseases.
Some of the worst diseases, such as HIV are found in semen. This was well-known before the study. However, some of the deadliest diseases that are very popular like Ebola, Zika, Mumps, and many other diseases were also found.

Can all these virus be transmitted through person to person contact?
In a research done,scientists discovered that the Zika virus can survive in semen for up to 6 months, people exposed to the disease-especially those hoping to have children-were horrified. It’s now known that the virus can be sexually transmitted up to 41 days.

READ ABOUT: Zika Virus : Structure, Epidemiology, Pathogenesis, Symptoms, Laboratory Diagnosis and Prevention

Now, a new meta-analysis has found that 26 other viruses can also live in human semen and go on to infect the bloodstream. Those include the viruses that cause Ebola, HIV, hepatitis B, and herpes.Though not all 27 viruses are capable of person-to-person transmission, they can have other serious consequences, like reducing fertility or increasing the risk of acquiring a sexually transmitted disease. Some of these viruses can even cause mutations in the DNA of sperm, which could then fertilize an egg and pass along the virus-induced mutations to future generations.

Monday, September 21, 2020

Why a vaccine is not an immediate solution for the COVID-19 pandemic but rather a long term solution!


Dr. Umair Shah remembers the last mass vaccination campaign the US waged. It was in 2009, when the H1N1 "swine" flu broke out in April, right at the end of the regular flu season. "That was very challenging," Shah, who heads the Harris County, Texas. "There were a lot of moving pieces. It took several weeks to months to not just organize but to implement and to do safely and effectively. And that was a mild pandemic." This is not a mild pandemic. And while vaccine manufacturers, public health experts, and the federal government are all confident one or more of the coronavirus vaccines being tested now will be shown to work safely by the end of the year, the US and the world will still be a long way from ending the pandemic.

"I feel cautiously optimistic that we will have a vaccine by the end of this calendar year, as we get into early 2021," Dr. Anthony Fauci, who, as director of the National Institute of Allergy and Infectious Diseases, is helping lead the medical battle against the virus, told CNN's Wolf Blitzer Friday.
"But it's not going to be turning a switch off and turning the switch on. It's going to be gradual," Fauci added.

First, any vaccine must either be approved or authorized by the US Food and Drug Administration. That's a process that under normal circumstances can take months or years. While the FDA has promised a speedier process for a Covid-19 vaccine, it must still go through a committee known as the Vaccines and Related Biological Products Advisory Committee, or VRBAC.
The FDA will almost certainly allow a shortcut process known as emergency use authorization, or EUA, but the agency has said it will require a "EUA-plus" that adds at least some layers of scrutiny.
"It's unlikely that a Covid-19 vaccine will receive full approval and broad distribution right away. Instead, the FDA will probably authorize vaccines for use in targeted groups of people at high risk from Covid and most likely to benefit from the vaccine," Dr. Mark McClellan and Dr. Scott Gottlieb, both former FDA commissioners, wrote in a commentary in the Wall Street Journal Monday. "All this means that at least initially, Covid vaccines won't provide the sort of herd immunity that can help extinguish an epidemic." That will take time likely well into next year, even if a vaccine were to be authorized in January.
"People can't be lulled into a false sense of security by knowing the vaccine is coming," Dr. Marcus Plescia, chief medical officer of the Association of State and Territorial Health Officers. Although manufacturers are already making vaccine doses, it takes time. And the US will likely need more than 600 million doses of the vaccine enough for everyone to get two doses of the vaccine.  "It won't be until we get into 2021 that you'll have hundreds of millions of doses, and just the logistics constraints in vaccinating large numbers of people it's going to take months to get enough people vaccinated to have an umbrella of immunity over the community."

The biggest mass vaccination program the US undertakes every year is the annual influenza vaccine. Only about half of Americans get a flu vaccine, and manufacturers make and distribute fewer than 150 million doses of it. Yet it takes a full year from start to finish to formulate, make, and distribute flu vaccines every influenza season. "We start planning for flu vaccines in January or February," Michael Einhorn, the president of Dealmed, an independent medical supply distributor covering New York, New Jersey, Connecticut, and Pennsylvania. Flu vaccines generally become available in August -- seven to eight months later. And that's with a vaccine made using familiar technology, and dispensed in ways that people are familiar with -- in pediatricians' offices, at pharmacies, in grocery stores, and at clinics.
"You have a playbook for influenza," Shah said. "This is not the same." Any coronavirus vaccines will involve new technology and a whole new process for distribution, administration, and then for payment. And while anyone can walk into, say, a pharmacy, get a flu shot and leave without ever thinking about it again, coronavirus vaccines will involve a whole lot more trouble and paperwork. People will probably need at least two doses about a month apart. Someone will have to track and follow up on that.
"We have to be able to see who has been vaccinated and who has not been," Dr. Ngozi Ezike, director of the Illinois Department of Public Health, told a public hearing about vaccine distribution organized by the National Academies of Science, Engineering, and Medicine. 
"To have two doses means that you provide the initial dose and we will need to bring the person back for a second dose a month later," Dr. Jinlene Chan, acting deputy secretary of public health for the state of Maryland. And it's very likely that vaccines made by several different companies will be in use by next year.  "We have to make sure that we give the person the same vaccine for their second dose that they got for their first dose," Chan said. No vaccination program can start until there are plans in place to manage this. Plus, the coronavirus vaccine or vaccines will still be experimental, so every person who gets one will need to be tracked to make sure there are no adverse reactions. There is no plan yet for any of this.
"We have gotten very little information on how this is going to roll out," said Harris County's Shah. "That makes it even more difficult to plan." One big potential stumbling block is what's known as the cold chain. The two vaccines furthest along in development both must be kept frozen. Moderna's vaccine must be kept at -4 degrees Fahrenheit (-20 degrees Celsius), while Pfizer's must be kept at -94 F (-70 C). While -4 isn't much colder than the optimal home freezer's setting of 0 degrees F, -94 is more of a challenge. "Throughout -- from every single point the vaccine has to traverse -- we have to maintain it at that temperature. Otherwise, there is a risk of some degradation and the vaccine possibly becoming less effective," Chan said. "We need to make sure that there is some capability to store it appropriately until it is ready to use."  Otherwise, a thawed batch could mean hundreds or even thousands of people get a dud vaccine. This can be a challenge, said Dr. Carlos del Rio, a vaccine expert at Emory University. "We simply don't have freezers that can reach minus 70 degrees in most clinics," he told the National Academies meeting.
To reach enough people, any mass vaccination effort will have to go beyond clinics, hospitals, and pharmacies. "You are going to have to get out to communities. You are going to have to get out to places of work," Del Rio said. That makes keeping the vaccines cold enough more of a challenge.
Plescia said Pfizer has a plan to help keep its vaccine cold. "Pfizer is going to have special boxes they ship the vaccines in, packed with dry ice," he said. "Once you get the box, it'll keep the stuff at negative 80 degrees for 10 days." But it's not clear, Plescia said, if the boxes could be opened and a few doses of vaccine taken out safely. "Even if these boxes work very well, it is still going to add a whole level of challenge," he said.
Adding to the timeline is simple biology. The Pfizer and Modern vaccines, at least, will have to be given in two doses, a month apart. After that, it takes about two weeks for immunity to build. That makes for six weeks from the time someone first gets vaccinated to when they can feel safe from infection.  On top of all of this, many Americans are fearful of vaccines -- especially a new one and especially a new vaccine rolled out in a time of intense politicization of the process. "There's general vaccination mistrust and then there's government mistrust," Ezike noted. The current atmosphere over mask use has not helped, added Harris County's Shah.

Unless a majority of the population gets vaccinated, the virus will continue its spread. Most estimates suggest that 60% to 70% of the population must be immune to provide enough herd immunity to interrupt the spread of the virus. Polls indicate that only about half of Americans feel confident right now about being vaccinated.  And if vaccines are less than fully effective, that may mean even more of the population needs to be vaccinated to have an effect on the spread. Then there are the unknowns.
"Testing has not been seamless at all. There are going to be some glitches," Plescia said. "I think there is a good chance there is going to be a vaccine that works and gets us out of this, but it is hard to believe that it is going to go really smoothly, given all the things that could happen." Shah is ready for unpleasant surprises. "This is a super slick virus that has broken every rule in the book," he said.
credit CNN.

Monday, September 14, 2020

Coronavirus vaccine: Everything you need to know

SARS-CoV-2, the virus that leads to coronavirus disease 19 (COVID-19), has spread rapidly from the first known cases in China in December 2019 to countries around the world.
What scientists are doing to develop a vaccine for the new coronavirus
On March 10, 2020, the World Health Organization (WHO) reported that there were 113,702 confirmed cases of COVID-19 around the world, plus 4,012 deaths.
In response to this global health crisis, researchers are working on developing a coronavirus vaccine as soon as possible.
Learn more about vaccine development and the possible timeline in this article.

scientists in a lab working on a coronavirus vaccineShare on Pinterest
Research into a coronavirus vaccine is ongoing.
Researchers striving to develop a coronavirus vaccine are working with different approaches, including:
  • whole virus vaccine
  • recombinant protein subunit vaccine
  • antibody vaccine
  • nucleic acid vaccine
The sections below will discuss these approaches in more detail.

Whole virus vaccine

Whole virus vaccines use weakened or dead forms of the virus that causes the disease.
They can be effective at providing immunity in the long run, but there is a risk that some people could develop symptoms of the illness due to the vaccination.
Reports state that Johnson & Johnson, Codagenix, and researchers at the University of Hong Kong are working on this kind of vaccine.

Recombinant protein subunit vaccine

Recombinant protein subunit vaccines do not carry the risk of causing an infection in people who receive them, because they do not contain any live pathogens.
Researchers are investigating whether or not they can make a recombinant protein subunit vaccine that targets a protein called spike (S-) protein. The new coronavirus uses the S-protein to attach to and infect cells.
Novavax, Clover Biopharmaceuticals, the University of Queensland, and a consortium led by Texas Children’s Hospital for Vaccine Development are using this approach to develop a coronavirus vaccine.

Antibody vaccine

Other researchers are investigating whether or not they can create a vaccine using antibodies from the SARS outbreak that began in 2002.
SARS has many similarities to COVID-19, as they are caused by related coronaviruses.
So far, scientists have shown that the antibodies that neutralize the SARS-causing virus can also limit how well the new coronavirus infects cells in laboratory studies.

Nucleic acid vaccine

Nucleic acid vaccines inject genetic material, such as DNA or RNA, into a live host. The cells that contain the new nucleic acid then make the proteins that were encoded in the DNA or RNA, which they present to the immune system.
Although the process is complex, nucleic acid vaccines enable the immune system to fight off particular pathogens.
Using nucleic acids such as DNA or RNA to deliver immunity is a promising approach, but to date, it is a technique only available in veterinary medicine.
However, researchers say that three companies are looking to develop a coronavirus vaccine using this approach: Inovio Pharmaceuticals, Moderna Therapeutics, and Curevac.

Projections for how long it will take to develop a coronavirus vaccine vary widely, depending on whether the person making the projection is a scientist, politician, or businessperson.
Politicians and manufacturers alike have implied that a coronavirus vaccine could be available within months.
However, based on their knowledge and experience, scientists say that developing a coronavirus vaccine:
If the timeline for the production and distribution of a coronavirus vaccine seems long, that is because there are many steps in place to ensure that it is safe and effective.
Specifically, once researchers create a potential vaccine, prospective producers must submit an Investigational New Drug Application to the Food and Drug Administration (FDA) that describes the product, the manufacturing process, and its effectiveness in animal testing.
In the next phase, a vaccine must successfully complete the following series of clinical trials:
  • Phase I: This evaluates the vaccine’s safety and ability to generate an immune system response in a small group of people.
  • Phase II: This tests many people, possibly hundreds, to determine the right dosage levels.
  • Phase III: This tests thousands of people to analyze the safety and effectiveness of the drug.

Specific medications to treat COVID-19 do not yet exist. Treatment will focus on alleviating symptoms while a person recovers.
Antibiotics cannot treat COVID-19, as they are meant for bacterial infections and have no affect on viruses such as coronavirus.
However, some researchers are looking at repurposing existing drugs, including antibiotics, as COVID-19 treatments. Learn more here.
Public health experts and medical professionals also recommend that people with the illness try to stay away from others during recovery.
Public health measures that limit the spread of infection include:
  • rapid testing and identification of sick people
  • isolation of people with COVID-19
  • social isolation, such as closing schools and businesses and canceling large gatherings
Different governments and organizations have taken varying approaches to limiting the spread of coronavirus.
People who think they have been exposed to someone with COVID-19 and develop symptoms such as a fever, cough, or trouble breathing should call their doctor, according to the CDC.
The most important thing that people with mild forms of the disease can do is make sure that they limit contact with others, especially older adults and those with compromised immune systems.
Some people with COVID-19 will require medical treatment, and some may need to stay in the hospital.
Before seeing a doctor or going to the hospital, however, a person should call the facility to alert them to the fact that someone is coming in who may have COVID-19. Also, wear a face mask on the way.
Hospitals are equipped with the medicine and personnel necessary to provide support for the most serious complications, including pneumonia and sepsis.

Vaccines work by prompting the immune system to make antibodies to defend the body against a specific disease, as if they had it.
The key is to do so without actually making the person sick.
After a person receives a vaccination, they develop immunity to the disease, which means that their bodies would be able to fight it off if they ever had exposure to it.
An effective vaccine must stimulate the immune system but not kick it into overdrive. Finding the right balance between an effective vaccine and one that does not cause unwanted side effects is a challenge for all vaccines under development.
During a health emergency, when speed is vital, this part may be the most significant factor to slow down the development of a safe new vaccine.
Vaccines also need to be safe for different groups of people to use, including young children, older adults, healthcare workers, and people with underlying health conditions.

To protect themselves and others from coronavirus, people can try:
  • frequently washing their hands with soap and hot water for at least 20 seconds
  • using hand sanitizer that contains at least 60% alcohol, if washing the hands is not possible
  • covering sneezes and coughing into the crook of the elbow
  • not touching their faces
  • regularly cleaning surfaces that people frequently touch, such as doorknobs
  • limiting or avoiding handshakes
  • staying home if sick

COVID-19 is currently a major health challenge as doctors and researchers work to develop effective preventive measures, such as vaccines.
Until a vaccine becomes available, people can protect themselves and others by following guidance from public health and medical experts.

Dangerous bacteria can survive disinfectant, putting patients at risk

Dangerous bacteria that pose a particular threat to the elderly and very sick hospital patients have been shown to survive on disposable hospital gowns and stainless steel surfaces — even after they're scrubbed clean.

The bacteria, called Clostridioides difficile or C. diff., cause almost a half million infections every year in the United States, according to the Centers for Disease Control and Prevention. An estimated 29,000 of those infected die.

The infection, which is spread by fecal to oral transmission, causes severe diarrhea, and can lead to intestinal inflammation and kidney failure. Those most at risk are people who have been given strong antibiotics, as well as those with long hospital stays, or those living in long-term care facilities like the elderly.

That means that keeping these facilities clean is incredibly important. But new research, published Friday in the journal Applied and Environmental Microbiology, shows how difficult that can be.

In lab studies, researchers found that C. diff spread easily from disposable gowns often employed in surgery or infection control to stainless steel and vinyl surfaces.

"The [bacteria] also transferred to vinyl flooring, which was quite disturbing. We didn't realize they would," said Tina Joshi, a lecturer in molecular microbiology at the University of Plymouth in the United Kingdom and lead author of the new study.

These bugs evolve. These bugs like to stay one step ahead. And even though we're using disinfectants and antibiotics appropriately, they still will become resistant in time. It's inevitable.

What's more, the bacteria didn't die when the researchers tried to kill them with concentrated chlorine disinfectant.

"Even if we applied 1,000 parts per million of chlorine, it would allow spores to survive in the gowns," Joshi told NBC News.

It's possible that increasing the amount of chlorine might kill the spores, but if the spores are indeed becoming resistant to the disinfectant, it will only be a matter of time before the stronger concentrations can't kill them.

"These bugs evolve. These bugs like to stay one step ahead. And even though we're using disinfectants and antibiotics appropriately, they still will become resistant in time. It's inevitable," Joshi said.

C. diff infections can occur when a patient is given broad spectrum antibiotics to tackle another infection.

Those antibiotics can wipe out a person's gut bacteria, but C. diff survive. That allows the bacteria to proliferate throughout the gut, and eventually come out in feces. If a person has severe diarrhea, for example, the bacteria can be launched into the air and spread around a room. That's when it's imperative to decontaminate clothing, curtains, tables and the bed.

If the bacteria aren't killed, hospital patients or people in nursing homes can become infected when they come into contact with contaminated surfaces, such as a bedside food tray.

But if traditional disinfectants are ineffective, as the new research suggests, what works?

One option is UV light, which could be useful in killing the bacteria. However, it can be challenging to make sure all surfaces are fully exposed to the light. At this point, Joshi said, highly concentrated bleach appears to be the best option.

For those who care for patients with compromised immune systems at home, the C. Diff Foundation says alcohol-based hand sanitizers are ineffective against the bacteria.

On its website, the group recommends instead using a cleaning solution of one cup bleach to nine cups of water, and leaving the mixture on surfaces for a minimum of 10 minutes.

Meanwhile, if C. diff spores can survive on gowns and other surfaces, it is likely also the case that they can live on doctor's coats and scrubs worn by hospital personnel all day.

"That's a real infection control hazard, because these spores can stick to fibers. We've proven that in this paper," Joshi said

Wednesday, September 2, 2020

Coronavirus: what are the latest scientific advances?

Coronavirus has accelerated scientific developments to a war time pace. Here are some of the significant scientific advances .

Antibody testing for all is on the horizon

Cheap, reliable antibody tests that reveal whether someone has previously hadCovid-19  are viewed as crucial for managing the next phase of the pandemic. Population-level screening can gauge the overall level of immunity and can allow people to incrementally return to work. Various teams around the world are already using lab-based antibody testing, but this is challenging to scale up, partly because the tests need to be performed a few weeks after infection. In parallel, companies have been working on home-testing kits that work something like a pregnancy test. This week, the UK government signalled it thought such tests could be reliable enough, announcing it had bought 3.5m testing kits, with a view to making them available first to healthcare workers, and then to the public through high street chemists or Amazon delivery. An unnamed prototype is being validated in Oxford this week and the proposal still hinges on the tests’ performance. “The one thing that is worse than no test is a bad test,” Chris Whitty, England’s chief medical officer, said on Wednesday. In Spain, the government was forced to withdraw 9,000 Chinese-made coronavirus testing kits from use after it emerged that they had an accurate detection rate of just 30%.

Covid-19 might affect your sense of smell and taste

Anecdotal reports have been circulating for weeks that Covid-19 can cause people to lose their sense of smell. This week, the idea gained credibility with the British Association of Otorhinolaryngology suggesting that so-called anosmia could be a useful symptom for screening for the virus, based on reports from South Korea, China and Italy, and higher than usual numbers reporting the complaint in UK clinics. On Monday, World Health Organization officials also said they were also looking into the possible link. “We are reaching out to a number of countries and looking at the cases that have already been reported to see if this is a common feature,” said Maria Van Kerkhove, the head of the WHO’s emerging diseases and zoonoses unit. “We don’t have the answer to that yet.”

The good news is that even if the coronavirus kills off some of your olfactory cells, the nose lining contains stem cells to make replacements. “Colleagues in Italy report encouraging rates of recovery, with many patients reporting return of sense of smell within seven to 14 days,” the British association advises. “This seems to be the experience of patients in the UK.”

The virus appears to be very stable

Coronaviruses, in general, don’t tend to mutate rapidly and this week scientists provided further reassurance that this is true for Covid-19. A team at Johns Hopkins University analysed 1,000 samples and, according to the Washington Post, found only four to 10 genetic differences between the strains circulating in the US and the original virus that was isolated from patients in Wuhan. An Italian analysis, also out this week, reached similar conclusions. This suggests that if an effective vaccine is found it should continue to work for some time. However, there is still an open question about how stable the human immune response is to Covid-19, and whether people who are infected once will be protected against reinfection long into the future.

Exit strategy

Hopes that life could get back to normal some time soon were dampened this week with models suggesting that lockdown measures need to remain in place for months to have their intended effect. A paper published in the Lancet suggested that if controls in Wuhan had been relaxed in early March, when case numbers dramatically dropped, the city would already be ramping up towards a fresh outbreak in June. China’s decision to maintain its lockdown until early April was estimated to reduce the average number of new infections by the end of 2020 by 24%. The restrictions currently in place in the UK will be reviewed on 13 April.

Men appear to be more susceptible to Covid-19

Evidence is growing that men are more likely to die from the disease than women. This was first observed in China, where the fatality rate was around 2.8% for men and 1.7% for women and the pattern has been mirrored as successive countries have released data. This week Spain reported that around twice as many men as women had died. The difference was initially put down to high rates of male smoking in China – about half of men smoke compared with just 2% of women. However, as the same trend has been replicated in countries with more equal proportions of male and female smokers, scientists are starting to consider other possibilities, including that women’s immune systems may be better able to overcome the virus. Serological studies from China, tracking the immune response throughout the course of infection, should soon start to provide some answers about why men appear more vulnerable and whether behaviour, lifestyle factors or biology is the leading factor.