It's not clear whether people who have recovered from COVID-19 are immune to the coronavirus that causes it, but a new research project at the University of Alberta will examine whether the antibodies their immune system produced to fight off the disease provides them with long-term immunity.
"There is some evidence from the literature that immunity is probably happening and we know now that this is probably reducing viral loads in individuals who are infected," said Steven Drews, a microbiologist in the U of A's Department of Laboratory Medicine and Pathology.
"But we really don't have a good sense of what the presence of just having antibodies means and what levels of antibodies we need to be protected."
To gain some insight into immunity levels of resolved COVID-19 infections, Drews will lead a team in a year-long study analyzing thousands of leftover blood samples from Canadian Blood Services donors looking for the presence of COVID-19 antibodies, and then analyzing antibody concentrations and how effective the antibodies are in preventing this specific coronavirus from infecting a host cell.
It's one of 13 research projects for which U of A researchers received $11.3 million in funding from the third round of the federal government's Rapid Research Funding Opportunity created to aid in the battle against COVID-19. Through three rounds of funding, 24 U of A research projects received $17.2 million in grants. The study is co-funded by Alberta Innovates.
"Once you've been infected, you can't stop that, but having enough pre-existing antibodies could blunt that infection and reduce your chances of having a severe disease or reduce the chance of having the virus, for example, move deeper into your respiratory tract," explained Drews, who is also associate director of microbiology at Canadian Blood Services.
He said the body's immune response to viruses is immensely complex. There are people who could have antibodies to the virus that still won't neutralize the virus. Others will have a good neutralizing response. Some people may generate antibodies to different antigens on the virus. Then there are some individuals who become infected and will mount a cell-based defence.
"There's a variety of immune responses that are probably happening when people become infected," said Drews.
"Maybe there's a special antibody out there that, although it might not be at a high level, could act as a neutralizing antibody and you need a more sensitive system to measure that."
While Drews doesn't necessarily think a therapeutic will emerge from the research, understanding what immunity looks like at a population level and how it holds up over time will help researchers develop better, more efficient tests and refine estimates of immunity in the population, which is fundamental to formulating public health policy.
"We will then pull in our epidemiologists, led by Sheila O'Brien at Canadian Blood Services, to help understand whether there are different regions in Canada that have different exposure levels, and maybe those populations, because they were impacted at different times, have different antibody responses," said Drews.
"This work will potentially guide our way forward if there are future waves in the pandemic, and possibly how to adjust for policy decisions and help educate the public about what these immune responses really mean."
Third round of CIHR grant recipients from the U of A
Steven Drews, Faculty of Medicine & Dentistry
Population-based seroprevalence of prior infection with COVID-19 in Canada: implications for testing, economic revitalization and population health.
$1 million
Joanne Lemieux, Faculty of Medicine & Dentistry
Optimizing polar, small inhibitors of a viral cysteine protease to identify a lead for an oral COVID-19 treatment
$585,000
John Lewis, Faculty of Medicine & Dentistry
Rapid prototyping and deployment of a therapeutic pan-coronavirus fusogenix DNA vaccine engineered to eliminate ADE
$4.23 million
Shannon MacDonald, Faculty of Nursing
Vaccination in a pandemic: The impact on routine vaccinations and future COVID-19 vaccine acceptance
$335,000
David Marchant, Faculty of Medicine & Dentistry
Broad-spectrum antiviral nasal spray to prevent and treat infection by SARS-CoV2 and seasonal respiratory viruses in high-risk patients and health-care providers
$662,000
Katerina Maximova, School of Public Health
Weathering adversity: Toward mitigating the impact of prolonged school closure and social isolation on mental health and lifestyle behaviours of elementary school children
$237,000
Patrick McLane, Faculty of Medicine & Dentistry
Equity in emergency department utilization in Alberta for priority populations during the COVID-19 pandemic: Exploring impacts of changes to health care and health-care utilization through administrative data analysis and nominal group techniques
$94,000
Candice Nykiforuk, School of Public Health
Public health response to COVID-19: Addressing financial strain-related health impacts of the pandemic
$449,000
Xiaoli Pang, Faculty of Medicine & Dentistry
Detection and quantitation of SARS-CoV-2 in wastewater to conduct surveillance on burden of community infection, identify outbreaks and support public health decision-making on control measures for transmission of COVID-19
$488,000
Ian Paterson, Faculty of Medicine & Dentistry
MOIST study: Multi-organ imaging with serial testing in COVID-19 infected patients
$342,000
Sangita Sharma, Faculty of Medicine & Dentistry
Capturing the anticipated/unanticipated consequences of COVID-19 and prevention, management, and treatment strategies among Indigenous peoples in Arctic communities
$1.52 million
Lorne Tyrrell, Faculty of Medicine & Dentistry
Characterization of interferon-lambda 1 as a treatment for COVID-19
$500,000
Lorne Tyrrell, Faculty of Medicine & Dentistry
Advancing a potent inhibitor of SARS-CoV-2 3CL protease into clinical trials
$904,000