Tag Archives: Antibodies

Chinese scientists seeking potential COVID-19 treatment find ‘effective’ antibodies

By Martin Quin Pollard

BEIJING (Reuters) – A team of Chinese scientists has isolated several antibodies that it says are “extremely effective” at blocking the ability of the new coronavirus to enter cells, which eventually could be helpful in treating or preventing COVID-19.

There is currently no proven effective treatment for the disease, which originated in China and is spreading across the world in a pandemic that has infected more than 850,000 and killed 42,000.

Zhang Linqi at Tsinghua University in Beijing said a drug made with antibodies like the ones his team have found could be used more effectively than the current approaches, including what he called “borderline” treatment such as plasma.

Plasma contains antibodies but is restricted by blood type.

In early January, Zhang’s team and a group at the 3rd People’s Hospital in Shenzhen began analysing antibodies from blood taken from recovered COVID-19 patients, isolating 206 monoclonal antibodies which showed what he described as a “strong” ability to bind with the virus’ proteins.

They then conducted another test to see if they could actually prevent the virus from entering cells, he told Reuters in an interview.

Among the first 20 or so antibodies tested, four were able to block viral entry and of those, two were “exceedingly good” at doing so, Zhang said.

The team is now focused on identifying the most powerful antibodies and possibly combining them to mitigate the risk of the new coronavirus mutating.

If all goes well, interested developers could mass produce them for testing, first on animals and eventually on humans.

The group has partnered with a Sino-U.S. biotech firm, Brii Biosciences, in an effort “to advance multiple candidates for prophylactic and therapeutic intervention”, according to a statement by Brii.

“The importance of antibodies has been proven in the world of medicine for decades now,” Zhang said. “They can be used to treat cancer, autoimmune diseases and infectious diseases.”

The antibodies are not a vaccine but could potentially be given to at-risk people with the aim of preventing them from contracting COVID-19.

Normally it takes around two years for a drug even to get close to approval for use on patients, but the COVID-19 pandemic means things are moving faster, he said, with steps that would previously be taken sequentially now being done in parallel.

Zhang, who posted the findings online, hopes the antibodies can be tested on humans in six months. If they are found to be effective in trials, actual use for treatment would take longer.

Other experts urge caution.

“There’s a number of steps which will now need to be followed before it could be used as a treatment for coronavirus patients,” Hong Kong University infectious disease specialist Ben Cowling said when the finding was described to him by Reuters.

“But it’s really exciting to find these potential treatments, and then have a chance to test them out. Because if we can find more candidates, then eventually we’ll have better treatment,” Cowling said.

(Additional reporting by Roxanne Liu; Editing by Kim Coghill; Editing by Tony Munroe, Kate Kelland and Kim Coghill)

U.S. companies, labs rush to produce blood test for coronavirus immunity

By Chad Terhune, Allison Martell and Julie Steenhuysen

(Reuters) – As the United States works overtime to screen thousands for the novel coronavirus, a new blood test offers the chance to find out who may have immunity – a potential game changer in the battle to contain infections and get the economy back on track.

Several academic laboratories and medical companies are rushing to produce these blood tests, which can quickly identify disease-fighting antibodies in people who already have been infected but may have had mild symptoms or none at all. This is different from the current, sometimes hard-to-come-by diagnostic tests that draw on a nasal swab to confirm active infection.

“Ultimately, this (antibody test) might help us figure out who can get the country back to normal,” Florian Krammer, a professor in vaccinology at Mount Sinai’s Icahn School of Medicine, told Reuters. “People who are immune could be the first people to go back to normal life and start everything up again.”

Krammer and his fellow researchers have developed one of the first antibody tests in the United States for COVID-19, the disease caused by the new coronavirus. Krammer said his lab is busy distributing key ingredients for the tests to other organizations and sharing the testing procedure. He is transferring the work to Mount Sinai’s clinical lab this week so it can begin testing patient samples.

Antibody tests won’t face the same bureaucratic hurdles diagnostic testing initially did. The U.S. Food and Drug Administration relaxed its rules last month, and body-fluid tests can proceed to market without full agency review and approval.

Several private companies have begun selling blood tests for COVID-19 antibodies outside the United States, including California-based Biomerica Inc <BMRA.O> and South Korean test maker Sugentech Inc <253840.KQ>. Biomerica said its test sells for less than $10 and the company already has orders from Europe and the Middle East. Chembio Diagnostics Inc <CMI.O> of New York said it received a $4 million order from Brazil for its COVID-19 antibody test, and it plans a study of the test at several sites in the United States.

Such tests are relatively inexpensive and simple, usually using blood from a finger prick. Some can produce results in 10 to 15 minutes. That could make ramping up screening much easier than for diagnostic tests.

Many questions remain, including how long immunity lasts to this new virus, how accurate the tests are and how testing would roll out, according to researchers and infectious disease experts. For now, the number of people who have been able to fight off the virus is unknown.

If testing goes forward on a wider scale, some public health experts and clinicians say healthcare workers and first responders should take priority.

Detecting immunity among doctors, nurses and other healthcare workers could spare them from quarantine and enable them to keep treating the growing surge of coronavirus patients, they say. It could also bolster the ranks of first responders, police officers and other essential workers who have already been infected and have at least some period of protection from the virus, the experts say.

“If I ever get the virus and then get over it, I’ll want to get back to the front lines ASAP,” said Dr. Adams Dudley, a pulmonologist and professor at the University of Minnesota School of Medicine. “I would have a period in which I am immune, effectively making me a ‘corona blocker’ who couldn’t pass the disease on.”

‘VERY ATTRACTIVE’

Other workers sidelined by lockdowns also could potentially return to their jobs, providing a much-needed boost to the foundering U.S. economy. The number of Americans filing for unemployment benefits has soared, and business activity slumped to a record low this month as the pandemic battered the manufacturing and service sectors.

Dr. William Schaffner, a professor of infectious diseases at the Vanderbilt University School of Medicine, said companies, schools, colleges and professional sports teams could all flock to these tests. He also said a broad sample of testing could give a governor or mayor enough confidence to lift certain restrictions on businesses and schools if there is a strong level of immunity.

“These tests would be very attractive if they’re cost effective, readily available and easy to do,” he said.

Tony Mazzulli, chief microbiologist with Toronto’s Sinai Health system, sounded a note of caution. It is uncertain whether antibodies would be sufficient protection if a person were to be re-exposed to the virus in very large amounts. That could happen in an emergency room or intensive-care unit, for instance.

The timing of a return to work and normal life also matters, he said. Some people who have antibodies to the virus could still be contagious, even if their symptoms have eased. Patients begin to make antibodies while they are still sick, Mazzulli said, and they continue to shed the virus for a few days after they have recovered.

It would be “a bit premature” to use the tests to make staffing decisions now, Mazzulli said. “The hope is … (antibodies) do confer protection and they can go to work, ride the subways, whatever they do. But there’s no guarantee.”

Meantime, at the Mayo Clinic  in Rochester, Minnesota, researchers are preparing to start a clinical trial in which patients who test positive for COVID-19 would have their blood collected at the time of diagnosis, and again 15 to 20 days after that in the patient’s home.

The trial is designed to show when people who have COVID-19 infections “seroconvert” – when antibodies produced by the body begin to show up in blood tests. That information will be useful in determining the best time to conduct the tests.

“You don’t want to do it too soon because of the risk of false negatives,” said Elitza Theel, director of Mayo’s Infectious Diseases Serology Laboratory.

Mayo also is evaluating the performance of antibody tests from several companies, including two from China.

The U.S. Centers for Disease Control and Prevention said it is working on its own version of antibody tests, but it has not given a timetable. The agency has said extensive research is underway. One challenge for the CDC and other labs is to get enough blood samples from people who have already been infected to verify the antibody results.

The agency faced heavy criticism for sending a faulty diagnostic test to state and local labs early in the coronavirus epidemic and then taking weeks to fix it. The federal government is still trying to expand diagnostic testing capacity.

MONTHS OF IMMUNITY

The potential for antibody testing arises as U.S. President Donald Trump is considering scaling back “social distancing” and stay-at-home advisories in the weeks ahead. His political allies argue that the toll on the U.S. economy is too severe. About half of Americans have been ordered to shelter in place as many schools and businesses remain shuttered indefinitely.

On Tuesday, Trump said: “I would love to have the country opened up and just raring to go by Easter.”

Reopening offices and businesses without fear of triggering more infections, however, has been complicated by the lack of testing to diagnose COVID-19 cases across much of the country.

On Monday, Dr. Deborah Birx, a member of the White House coronavirus task force, said simple, finger-prick antibody tests could play an important role, and she suggested the federal government is not waiting on the CDC’s version.

“Some are developed now. We are looking at the ones in Singapore,” Birx said Monday at a White House press briefing. “We are very quality-oriented. We don’t want false positives.”

False positives are erroneous results that, in this case, could lead to a conclusion that someone has immunity when he or she does not.

Researchers at the Duke-National University of Singapore Medical School said they quickly developed one antibody test that had about 90% accuracy and later introduced a more sophisticated version that was more reliable, according to a report in the Straits Times of Singapore.

Infectious disease experts say immunity against COVID-19 may last for several months and perhaps a year or more based on their studies of other coronaviruses, including Severe Acute Respiratory Syndrome (SARS), which emerged in 2003. But they caution that there is no way to know precisely how long immunity would last with COVID-19, and it may vary person to person.

“You are likely to have immunity for several months,” said Dr. Stanley Perlman, a professor of microbiology and immunology at the University of Iowa. “We just don’t know. This is an incredibly important question.”

Perlman said many of the new antibody tests coming on the market now may be highly effective, but researchers want to see data to back that up.

“You want them to be sensitive enough to detect everyone who has had the infection,” Perlman said, “but not so nonspecific that you are picking up other coronaviruses.”

(This story has been refiled to fix Bioamerica Inc RIC)

(Chad Terhune reported from Los Angeles, Julie Steenhuysen from Chicago and Allison Martell from Toronto; Editing by Julie Marquis)

U.S. measles outbreak raises questions about immunity in adults

FILE PHOTO: An illustration provides a 3D graphical representation of a spherical-shaped, measles virus particle studded with glycoprotein tubercles in this handout image obtained by Reuters April 9, 2019. Centers for Disease Control and Prevention (CDC)/Handout via REUTERS/File Photo

By Julie Steenhuysen

(Reuters) – Adults in the United States who were vaccinated against measles decades ago may need a new dose depending on when they received the shot and their exposure risk, according to public health experts battling the nation’s largest outbreak since the virus was deemed eliminated in 2000.

Up to 10 percent of the 695 confirmed measles cases in the current outbreak occurred in people who received one or two doses of the vaccine, according to the U.S. Centers for Disease Control and Prevention.

The figure illustrates what can happen when a large number of individuals, even those who have been vaccinated, are exposed to the measles. CDC recommends that people who are living in or traveling to outbreak areas should check their vaccination status and consider getting a new dose.

Dr. Allison Bartlett, an infectious disease expert at the University of Chicago Medicine, said the “continued vulnerability to infection” is why high-risk adults such as healthcare workers are routinely advised to get a second dose of the measles vaccine if they have not had one.

But knowing your vaccination status can be tricky, experts said.

“It’s complicated and often futile because it’s very difficult to resurrect those old records,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center.

People vaccinated in the United States since 1989 would most likely have received two doses of the combined measles, mumps and rubella (MMR) shot under federal guidelines, and that is still considered the standard for protection.

Anyone vaccinated between 1963 and 1989 would likely have received only one dose, with many people immunized in the earlier years receiving an inactivated version of the virus. Americans born before 1957 are considered immune as they would have been exposed to the virus directly in an outbreak.

Merck &amp; Co Inc is the sole U.S. provider of the MMR vaccine. The company said in a statement that it has “taken steps to increase U.S. supply” of the vaccine due to the current outbreak.

HIGHLY CONTAGIOUS

The measles virus is highly contagious and can cause blindness, deafness, brain damage or death. It is currently spreading in outbreaks in many parts of the world.

According to the World Health Organization, 95 percent of a population needs to be vaccinated to provide “herd immunity,” a form of indirect protection that prevents infection in people too young or sick to be vaccinated. U.S. public health officials have blamed the current outbreak in part on rising rates of vaccine skepticism that have reduced measles immunity in certain communities.

For travelers to outbreak areas abroad, the CDC recommends adults consider getting another dose of MMR unless they have proof of receiving two prior doses, take a blood test showing immunity, or were born before 1957.

In general, the CDC says two doses of the measles vaccine should provide 97 percent protection; one dose should offer 93 percent protection. However, immunity can wane over time.

This has occurred even in adults with two documented doses of the vaccine, said Dr. Michael Phillips, chief epidemiologist at NYU Langone Health, which serves parts of New York City, a hot spot in the U.S. outbreak.

He said in kids, “the vaccine is really effective,” but in some adults, memory T-cells, which recognize and attack germs, do not fight the virus as effectively as they once did.

Rapid blood tests are available that can detect whether a person is immune based on the level of measles antibodies, but the tests are not 100 percent reliable.

Adults who have any doubt about their immunity should get another dose, Schaffner said: “It’s safe. There’s no downside risk. Just roll up your sleeve.”

(Reporting by Julie Steenhuysen in Chicago; Additional reporting by Mike Erman and Gabriella Borter in New York; Editing by Lisa Shumaker)

Man’s Blood Saves Two Million Babies

An Australian man is being called “the Man with the Golden Arm” for saving two million newborns because of donating his plasma.

James Harrison has a rare blood type that contains life-saving antibodies.  Doctors believe that Harrison somehow developed the antibody during an operation at age 14 where he had a lung removed.

Now, Harrison’s blood is used to create the vaccine Anti-D.  The vaccine is used to treat pregnant women with a blood disease that can lead to complications.  Harrison has donated every week for the last 60 years, over 1,000 times.

“In Australia, up until about 1967, there were literally thousands of babies dying each year. Doctors didn’t know why, and it was awful,” Jemma Falkenmire, of the Australian Red Cross Blood Service, told CNN. “Women were having numerous miscarriages, and babies were being born with brain damage.”

The condition is called Rhesus disease and happens when a woman has rhesus-negative blood and her baby has rhesus-positive blood.  The mother can produce antibodies that begin to attack the baby.  The Anti-D vaccine prevents the antibodies that attack the baby from developing.

“It makes you feel good yourself that you’ve saved a life there, and you’ve saved many more— and that’s great,” Harrison, who added he does not see himself as a hero, told CNN.

The Australian Red Cross says that 17 percent of Australian women are risk for the disease and they hope another donor can be found before Harrison reaches 81, the age limit for blood donation in the country.