Scripps Research scientists have discovered a common molecular feature found in many of the human antibodies that neutralise SARS-CoV-2, the coronavirus that causes COVID-19.
This is coming as Nigeria on Monday logged 37225 COVID-19 cases and 801 deaths. These tallies are a sequel to 562 new confirmed cases, and 12 deaths recorded in the country within 24 hours.
According to the Nigeria Centre for Disease Control (NCDC), ‘’till date, 37225 cases have been confirmed, 15333 cases have been discharged and 801 deaths have been recorded in 36 states and the Federal Capital Territory, Abuja.’’
Of the 562 new cases from 21 states, Abuja hit the front burner with 102 cases, followed by Lagos’ 100, Plateau 52, Kwara 50, Abia 47, Kaduna 35, Benue 34, Oyo 26, Ebonyi 24, Kano 16, Niger 15, Anambra 14, Gombe 12, Edo 11, Rivers six, Nasarawa five, Delta five, Borno three, Enugu two, Bauchi two, and Kebbi one.
Despite the surging virus in the country, Abuja is usy warning of the outbreak of another pandemic if Nigeria fails to take advantage of opportunities presented by the COVID-19 crisis to develop its health infrastructure.
Secretary to the Government of the Federation (SGF) and Chair of the Presidential Task Force on COVID-19, Boss Mustapha, on Monday says, “it will be the greatest disappointment of our time and of our generation if we do not seize the opportunity of the moment to redress all the deficiencies of the defects that we’ve had in our health and other infrastructure in this country.’’
Insisting, he says if the country fails to seize the moment to fix its healthcare infrastructure, it will find itself starting all over again if confronted with another pandemic.
Mustapha was speaking in Abuja, while inaugurating the Board of Experts (BoE) of the Healthcare Sector Research and Development Intervention Scheme (HSRDIS).
“If we had built on the experiences of Ebola and other epidemics that we have dealt with in the past, probably today we wouldn’t have started with about two molecular laboratories for the testing of COVID-19.
“If you travel the shores of this country, you will find out that we have over 10,000 public primary healthcare centres scattered in wards and villages across the country, ill-equipped, ineffective and not being put into use but we keep building them’’, he said.
Continuing, he urged members of the board to also look at governance structures in the healthcare sector apart from their primary responsibilities, adding, “COVID-19 has exposed the weaknesses in our health system, in our governance system, in our security infrastructure, in our inclusiveness and creating social safety nets for our people.’’
Mustapha equally urged the citizenry to continue social distancing, wear a mask and wash their hands to prevent a second wave and the further spread of the virus.
However, Scripps Research enjoys a rich history of academic and scientific achievement. Its world-class faculty and visionary leadership have partnered to create a top-ranked nonprofit biomedical research institute that translates discoveries into new medicines while training the next generation of scientists.
Its world-renowned scientists at Scripps Research have joined forces to understand and overcome the novel coronavirus behind COVID-19.
With expertise in epidemiology, microbiology, bioinformatics and drug development—among other key disciplines—teams are working around the clock on discoveries that will help contain the virus, lead to vaccines and medicines, and prepare for future pandemics.
Their study has already appeared on July 13 Science, reviewed data on nearly 300 anti-SARS-CoV-2 antibodies that their labs and others have found in convalescent COVID-19 patients over the past few months.
They noted that a subset of these antibodies is particularly powerful at neutralising the virus—and these potent antibodies are all encoded, in part, by the same antibody gene, IGHV3-53.
Those who know better say the scientists used a powerful tool known as X-ray crystallography to image two of these antibodies attached to their target site on SARS-CoV-2.
The resulting atomic-structure details of this interaction should be useful to vaccine designers, as well as to scientists hoping to develop antiviral drugs targeting the same site on SARS-CoV-2.
Prior research suggests that antibodies encoded by IGHV3-53 are generally present, at least in small numbers, in healthy people’s blood.
The results, therefore, offer hope that using a vaccine to boost levels of these ever-present antibodies will protect adequately against the virus.
“This type of antibody has been isolated frequently in studies of COVID-19 patients, and we can now understand the structural basis for its interaction with SARS-CoV-2”, says the study’s senior author Ian Wilson, DPhil, Hansen Professor of Structural Biology and Chair of the Department of Integrative Structural and Computational Biology at Scripps Research.
“This study provides important inspiration for effective COVID-19 vaccine design,” says co-author Dennis Burton, Ph.D., professor and co-chair of the Department of Immunology and Microbiology at Scripps Research.
The research was a collaboration chiefly involving the Wilson and Burton labs, and the Scripps Research-based Neutralizing Antibody Center of IAVI, a prominent non-profit vaccine research organization.
SARS-CoV-2 so far has infected more than 12 million people around the world and killed more than 500,000, in addition to causing widespread socioeconomic disruption and damage. Developing an effective vaccine to stop the pandemic is currently the world’s top public health priority.
Although several potential vaccines are already in clinical trials, scientists don’t yet have a full understanding of the molecular features that would define a protective antibody response. In the new study, the scientists took a big step toward that goal.
The team started by analyzing 294 different SARS-CoV-2-neutralizing antibodies isolated from COVID-19 patients’ blood over the past few months. Antibodies are Y-shaped proteins made in immune cells called B-cells.
Each B-cell makes a specific antibody type, or clone, which is encoded by a unique combination of antibody genes in the cell. The scientists found that an antibody gene called IGHV3-53 was the most common of the genes for the 294 antibodies, encoding about 10 percent of them.
The scientists also noted that the IGHV3-53-encoded antibodies in their study contain an unusually short variant of the CDR H3 loop, normally a key target-binding element. These antibodies are nevertheless very potent against SARS-CoV-2 when compared to other antibodies not encoded by IGHV3-53.
The IGHV3-53 antibodies had yet another property suggesting that boosting their numbers would be a good and achievable aim for a SARS-CoV-2 vaccine: They appeared to have mutated only minimally from the original versions that would be circulating, initially in small numbers, in the blood of healthy people.
Normally, when activated by an encounter with a virus to which they fit, B-cells will start proliferating and also mutating parts of their antibody genes, in order to generate new B-cells whose antibodies fit the viral target even better.
The more mutations needed for this “affinity maturation” process to generate virus-neutralising antibodies, the harder it can be to induce this same process with a vaccine.
Fortunately, the IGHV3-53 antibodies found in the study seemed to have undergone little or no affinity maturation and yet were already very potent at neutralizing the virus—which hints that a vaccine may be able to induce a protective response from these potent neutralisers relatively easily.
“Coronaviruses have been around for hundreds to thousands of years, and one can imagine that our immune system has evolved in such a way that we carry antibodies like these that can make a powerful response right off the bat, so to speak”, Wilson says.
Wilson’s team used high-resolution X-ray crystallography to image two different IGHV3-53 antibodies bound to their target on SARS-CoV-2. This target, known as the receptor binding site, is a crucial structure on the viral “spike” protein that normally connects to a receptor on human cells to begin the process of cell infection. Many of the antibodies that neutralize SARS-CoV-2 appear to do so by blocking this virus-receptor connection.
“We were able to reveal unique structural features of these IGHV3-53-encoded antibodies—features that facilitate their high binding affinity and their specificity for the SARS-CoV-2 receptor binding site”, says co-first author Meng Yuan, Ph.D., a postdoctoral research associate in the Wilson lab.
The detailed atomic-scale structural data should be of interest to vaccine designers and drug developers. Moreover, the researchers say, the identification of IGHV3-53-encoded antibodies as key elements of the immune response to COVID-19 suggests that levels of these antibodies might be useful as an indirect marker of success in ongoing and future vaccine trials.
