Biolidics develops test detecting a person’s protective immunity against Covid-19; shares jump

‘Biolidics said the ClearEpi NAB Test is intended for the qualitative detection of circulating human IgG  antibodies capable of attaching to the Covid-19 spike proteins and preventing binding. "The company wishes to highlight that the ClearEpi NAB Test is intended for use as an aid in identifying individuals with an adaptive immune response to Sars-CoV-2 and should not be used to diagnose or exclude acute Sars-CoV-2 infection," Biolidics added.

‘Biolidics expects the development of the test and the receipt of the CE marking to contribute positively to its revenue for the financial year ending Dec 31, 2021, provided the company is able to successfully market and commercialise the test in the EU.’

Read here (Straits Times, Sept 15, 2021)

The antibody deception

‘Virtually every study and piece of marketing material related to Covid is premised on scientists having positively and correctly identified the presence of the novel coronavirus (also known as SARS-CoV-2) in the material they’re working with.

‘The job of that identification is usually given to antibodies that are said to bind to the novel coronavirus. The assumption is these antibodies are able to pick out the virus and only the virus from among every other organism and substance surrounding it.

‘Unfortunately it turns out that the antibodies rarely (if ever) do that. This is because of, among other things, inadequate verification of the antibodies’ accuracy in targeting the virus by the companies that manufacture and sell them. And there’s even less verification by government regulators.’

Read here (OffGuardian, Mar 6, 2021)

Coronavirus antibody therapies explained

How do bamlanivimab and REGN-CoV-2 work?: ‘Both antibody treatments are designed to block the SARS-CoV-2 spike protein and thus prevent the virus from attaching to and entering human cells. These identical so-called monoclonal antibodies are lab-engineered and designed to attack one specific virus in one distinct way.

‘Bamlanivimab contains one monoclonal antibody. REGN-CoV-2, in contrast, consists of two monoclonal antibodies. US pharma company Regeneron says its antibody cocktail lowers the viral load, which helps symptoms dissipate more quickly.

‘The advantage of Regeneron's drug cocktail is that by containing two antibodies, it increases the chance that at least one of them will prove effective during treatment, virologist Sandra Ciesek told German public broadcaster NDR.’

Read here (DW, Jan 29, 2021)

Pregnant women can pass antibodies to their foetus: Some implications for vaccinations

‘A study published in JAMA: Pediatrics provides evidence that pregnant women may be able to pass IgG antibodies against SARS-CoV-2 to their fetus. The study involved 1,417 women who recently gave birth. Among 83 mothers with detectable SARS-CoV-2 antibodies, 72 (86.7%) transferred IgG antibodies to their fetus—as detected in the newborns’ cord blood. IgM antibodies were not detected in any cord blood specimens, and antibodies were not detected in any infants born to mothers without detectable antibodies. The concentration of antibodies in the cord blood was significantly correlated with the concentration in the mother, but the antibodies were successfully transferred by mothers who exhibited symptomatic disease and asymptomatic infection. The study did not explicitly evaluate the ability to transfer antibodies developed as a result of vaccination; however, the researchers indicate that the results align with similar studies on transplacental transfer of vaccine-conferred antibodies for other diseases. Further research is necessary to determine the recommended timing for vaccination of pregnant women in order to achieve sufficient transplacental transfer of SARS-CoV-2 antibodies to the fetus.’ [John Hopkins Newsletter]

Assessment of maternal and neonatal cord blood SARS-CoV-2 antibodies and placental transfer ratios

‘Our findings demonstrate the potential for maternally derived antibodies to provide neonatal protection from SARS-CoV-2 infection and will help inform both neonatal management guidance and design of vaccine trials during pregnancy. Further studies are needed to determine if SARS-CoV-2 antibodies are protective against newborn infection; if so, at what concentration; and whether the transplacental kinetics of vaccine-elicited antibodies are similar to naturally acquired antibodies.’

Read here (Jama Pediatrics, Jan 29, 2021)

Regeneron says monoclonal antibodies prevent Covid-19 in study

‘Regeneron said Tuesday that its monoclonal antibody cocktail prevented Covid-19 in a clinical trial. The news, issued via a press release, mirrored similar news from Eli Lilly last week that its monoclonal antibody prevented symptomatic Covid-19 infections in nursing homes.

‘The results represent the first 400 volunteers from the study, which is being run by the National Institute of Allergy and Infectious Diseases (NIAID), and is continuing to enroll patients. The volunteers were at high risk of infection because they lived in the same household as a Covid-19 patient. Half the patients received a placebo, and the other half received 1.2 grams of casirivimab and imdevimab, Regeneron’s antibodies.’

Read here (Stat News, Jan 26, 2021)

Eli Lilly says its monoclonal antibody, bamlanivimab, prevented Covid-19 infections in clinical trial

‘Eli Lilly said Thursday that its monoclonal antibody prevented Covid-19 infections in nursing home residents and staff in a clinical trial, the first time such a treatment has been shown to prevent infection. Lilly released the results in a press release, although it said that it would publish the data in a research paper as quickly as possible.

‘In November, the antibody, bamlanivimab, was authorized for emergency use by the Food and Drug Administration in treating patients with Covid who are at risk of more severe disease. An antibody cocktail made by the biotechnology firm Regeneron has also been authorized... But Lilly believes its antibody could be an option not just to treat Covid-19 but to help prevent it in limited circumstances.’

Read here (STAT News, Jan 21, 2021)

UK scientists trial drug to prevent infection that leads to Covid

‘British scientists are trialling a new drug that could prevent someone who has been exposed to coronavirus from going on to develop the disease Covid-19, which experts say could save many lives.

‘The antibody therapy would confer instant immunity against the disease and could be given as an emergency treatment to hospital inpatients and care home residents to help contain outbreaks. People living in households where someone has caught Covid could be injected with the drug to ensure they do not become infected too. It could also be given to university students, among whom the virus has spread rapidly because they live, study and socialise together.’

Read here (The Guardian, Dec 25, 2020)

Babies born to mums with Covid-19 may have antibodies, but scope of protection is unclear

‘Although babies of women infected with Covid-19 during their pregnancies have been born with antibodies, it remains unclear if this means the baby is immune to the coronavirus or how long the immunity would last. Earlier this month, Mrs Celine Ng-Chan, 31, gave birth to her second child and was told by her son's paediatrician that he has antibodies against the virus.’

Read here (Straits Times, Nov 29, 2020)

NEJM paper on Iceland throws into question Imperial College team results: Antibodies stable after 4 months. Also death rate 0.3%, 44% not diagnosed

‘Our results indicate that antiviral antibodies against SARS-CoV-2 did not decline within 4 months after diagnosis. We estimate that the risk of death from infection was 0.3% and that 44% of persons infected with SARS-CoV-2 in Iceland were not diagnosed by qPCR.‘

Read here (NEJM, Oct 29, 2020)

Read here the BBC story on Imperial College study that says antibodies drop rapidly  

Antibodies ‘fall rapidly after infection’

‘Levels of protective antibodies in people wane "quite rapidly" after coronavirus infection, say researchers. Antibodies are a key part of our immune defences and stop the virus from getting inside the body's cells. The Imperial College London team found the number of people testing positive for antibodies has fallen by 26% between June and September. They say immunity appears to be fading and there is a risk of catching the virus multiple times. The news comes as figures from the Office for National Statistics show that the number of Covid-19 deaths in the UK rose by 60% in the week of 16 October.’

Read here (BBC, Oct 28, 2020)

Read here NEJM paper on Iceland which throws into question this

How Singapore helped with US President Trump's Covid-19 treatment

 ‘When it comes to fighting against the Covid-19 pandemic, Singapore has been punching above its weight. Blood samples from three patients here were used to develop the experimental antibody cocktail used to treat US President Donald Trump after he tested positive for the coronavirus.

‘The National Centre for Infectious Diseases (NCID) had responded to a collaboration request from US biotechnology firm Regeneron - the company which developed that antibody cocktail - with no claim of intellectual property right over the treatment.’

Read here (Straits Times, Oct 10, 2020)

Iceland has very good news about coronavirus immunity

‘A study on the pandemic in Iceland published in the New England Journal of Medicine offers some evidence to dispel such fears. The researchers have looked at serum samples from 30,576 individuals, using six different types of antibody testing (since different techniques often produce conflicting results).

‘The paper’s central findings are that, out of 1,797 tested people who’d recovered from Covid, 91.1% produced detectable levels of antibodies. Moreover, these levels hadn’t declined four months after the diagnosis. The immune response was higher among older individuals — who are at greater risk of developing a more dangerous form of the coronavirus — and among those who presented the worst symptoms.’

Read here (Bloomberg, Sept 3, 2020)

US announces major clinical trial of antibody treatment

‘The US has begun late stage clinical trials into a drug formulated to fight Covid-19, officials said Tuesday. The medicine is an antibody against the new coronavirus called LY-CoV555, which was identified in the blood sample of a recovered patient by Canada’s Abcellera Biologics. It was then developed synthetically for mass production by US-based Lilly Research Laboratories in partnership with Abcellera. The Phase 3 trial will initially enrol some 300 volunteers around the world who have been hospitalised with mild to moderate Covid-19 with fewer than 13 days of symptoms.’

Read here (South China Morning Post, August 4, 2020)

Antibody levels in recovered COVID-19 patients decline quickly, Chinese study finds

‘Levels of an antibody found in recovered COVID-19 patients fell sharply in two to three months after infection for both symptomatic and asymptomatic patients, according to a Chinese study, raising questions about the length of any immunity against the novel coronavirus. The research, published in Nature Medicine on Jun 18, highlights the risks of using COVID-19 "immunity passports" and supports the prolonged use of public health interventions such as social distancing and isolating high-risk groups, researchers said.’

Read here (Channel News Asia, June 22, 2020)

Coronavirus antibody tests have a mathematical pitfall

‘...such [antibody] tests have been proposed as a way for individuals to find out if they have already been infected with the novel coronavirus. But a mathematical wrinkle makes these tests—and in fact, all screening tests—hard to interpret: even with a very accurate test, the fewer people in a population who have a condition, the more likely it is that an individual's positive result is wrong. If it is, people might think they have the antibodies (and thus may have immunity), when in fact they do not.

‘A positive screening test result for other diseases usually prompts follow-up testing to confirm a diagnosis. But for COVID-19 screening, such follow-up has been rare because testing resources are scarce or because other testing methods are prioritized for the sickest patients. Here's a look at the massive impact infection rates can have on the predictive value of these tests for individuals.’

Read here (Scientific American, July 2020, pre-published in June 19, 2020)

Antibody tests don't mean a ton right now. But that could change soon

‘In the study published in medRxiv, a preprint server for posting studies before they are peer-reviewed, a team at the Lindsley F. Kimball Research Institute of the New York Blood Center and Rockefeller University analyzed 370 plasma samples donated from people who recovered from COVID-19 and found some surprising results...

‘Overall, around 88% of the people generated varying levels of antibodies to the virus. But only about 10% of them had high levels that were able to neutralize the lab-based version of the COVID-19 virus—and, on the other side of the spectrum, 17% had almost no antibody response to their infection.’

Read here (Time Magazine, June 16, 2020)

Covid 19 coronavirus 'cure'? US biotech company claims it's found antibody to block virus

‘A California-based biotech company claims it has found an antibody that completely blocks the new coronavirus. Sorrento Therapeutics said its STI-1499 antibody stopped Covid-19 from entering 100 per cent of healthy human cells in their experiments, Fox News reports. The antibody is one of several the biotech company is planning to combine for a collaboration with Mt Sinai School of Medicine in New York.’

Read here (NZ Herald, May 16, 2020)

Study shows most people carry antibodies after recovery from coronavirus

‘A new study offers a glimmer of hope in the grim fight against the coronavirus: Nearly everyone who has had the disease - regardless of age, sex or severity of illness - makes antibodies to the virus. The study, posted online on Tuesday (May 5) but not yet reviewed by experts, also hints that anyone who has recovered from infection may safely return to work - although it is unclear how long their protection might last.’

Read here (Straits Times, May 8, 2020)

What Covid-19 antibody tests can and cannot tell us

‘Dozens of antibody tests for the novel coronavirus have become available in recent weeks. And early results from studies of such serological assays in the U.S. and around the world have swept headlines. Despite optimism about these tests possibly becoming the key to a return to normal life, experts say the reality is complicated and depends on how results are used.

‘Antibody tests could help scientists understand the extent of COVID-19’s spread in populations. Because of limitations in testing accuracy and a plethora of unknowns about immunity itself, however, they are less informative about an individual’s past exposure or protection against future infection.’

Read here (Scientific American, May 5, 2020)

Famed HIV researcher on the race to find a Covid-19 treatment

‘David Ho is in a race against time to find a treatment for COVID-19. Fortunately it's the kind of race he's run before. Ho, the famed virologist and director and CEO of the Aaron Diamond AIDS research center at Columbia University, rose to prominence decades ago with his HIV research. Now he's working to develop a drug that can interrupt the coronavirus' ability to replicate, which, if successful, could lead to a treatment for COVID-19. His team is also studying antibody responses to the virus and is among dozens of labs racing to develop treatments.

‘The Jack Ma Foundation recently gave Ho and other researchers at Columbia University a $2.1 million grant to support their efforts to identify antiviral drugs and antibodies that can be used to fight the coronavirus.

‘Ho: My group is not so much working on a vaccine. We're trying to discover small-molecule drugs or develop antibodies that can be used either as prophylactics or therapeutics. We think the timeline for antibodies in particular can be much faster. We know we have the technology to fish out and construct very powerful antibodies that can be used to treat the infection, as well as prevent the infection.’

Read here (NBC News, May 1, 2020)