The COVID-19 pandemic is still continuing around the world. Scientists are constantly looking for ways to not only improve the efficacy of the current vaccine against SARS-CoV-2, but go further and create a universal vaccine that protects against a wide variety of coronaviruses, including the common cold.
The new study found that a vaccine that focuses on the S2 portion of the SARS-CoV-2 spike protein is able to create antibodies that not only deal with SARS-CoV-2, but also neutralize other coronaviruses. The design was tested in vitro and on animal models. The findings are reported in Science Translational Medicine.
"Our goal was to develop a novel vaccination approach against the SARS-CoV-2 variant and any new variants that might emerge in the future," said study lead author Kevin Ng, a graduate researcher at The Francis Crick Institute.
"To do this, we created a vaccine based on the S2 region of the spike protein, which is part of the protein that viruses use to enter cells. When we vaccinated mice with this S2 vaccine, they produced antibodies that bind to and block various human and animal coronaviruses, including the SARS-CoV-2 variant and the common cold Corona virus," he continued.
Vaccinating mice with SARS-CoV-2 S2 led to the formation of antibodies in these animals to not only deal with some of the variants of the COVID-19 virus we've been exposed to so far, but also the common cold virus HCoV-OC43, as well as two coronaviruses found in bats. S2 seems to be a very promising target.
"We became interested in the S2 region a few years ago when we discovered that antibodies targeting the common cold coronavirus can also bind to SARS-CoV-2," Ng said.
"We realized that this cross-reactive antibody binds specifically to the S2 region, which is nearly identical in all human-infecting coronaviruses. This type of evolutionary conservation implies that the Coronavirus has difficulty mutating in this region, and when we actually see all SARS-CoV variants -2 which has evolved over the past two years, S2 remains pretty much the same.
S2 is also very similar across many different animal coronaviruses, meaning that vaccines that target it can prevent animal viruses from effectively jumping to humans. This could be a way to stop future pandemics before they even have a chance to start.
Vaccines do not guarantee that a person will never get the flu or COVID again. However, the effect will be much milder, significantly reducing the chances of hospitalization and death of the most dangerous members of the Corona virus family.
"It is very challenging to design a vaccine that prevents infection with the Corona virus. This is why we are reinfected with the common cold every year," Ng explained.
"Our current vaccine is very good at preventing severe illness and hospitalization, and we hope that our vaccine can be incorporated into existing vaccination regimens or given as a booster to train our immune system to recognize more types and variants of the Corona virus," he said. .
Despite the exciting results, the road to such a vaccine being available in humans is still a long way off. But similar approaches are being investigated and a pan-coronavirus vaccine may be more real than we think.
"For now, this work is just a proof-of-concept in cells and in mice, and the next step is to test this vaccine in preclinical animal models that better mimic the history of Corona virus infection and vaccinations we have as humans," Ng said.
"However, there are a number of different pan-coronavirus vaccines in development, including some that have just started human trials."