Spike protein changes explain repeat COVID infections

A sign alerts people to a COVID-19 testing site in Times Square on May 03, 2022 in New York City. (Credit: Spencer Platt/Getty Images)

As new Omicron subvariants of COVID-19 continue to sweep across the United States, researchers have identified specific mutations within the virus’ spike protein that help the subvariants evade existing antibodies from either vaccines or previous COVID-19 infections.

These mutations help explain why some people are continuing to test positive for the coronavirus, which, like most viruses, continues to evolve.

“The various mutations may seem like only subtle differences, but they are very important.”

The findings can help developers of COVID-19 treatments and vaccines consider which parts of the virus to target going forward to produce the most effective outcomes.

The researchers analyzed protein sequences from more than 10 million Omicron-related coronavirus samples collected since November 2021 from around the world.

“Throughout the pandemic, the virus has continued to get smarter and smarter. Even with vaccines, it continues to find new ways to mutate and evade existing antibodies,” says Kamlendra Singh, a professor in the University of Missouri College of Veterinary Medicine and Christopher S. Bond Life Sciences Center principal investigator.

“Omicron now has more than 130 sublineages, and they have been here for quite a while. We are now just finally able to detect them and differentiate among them with this research. Previous variants, including Alpha, Beta, Gamma, and Delta, contributed to many of the mutations occurring now with these Omicron variants. So our research shows how the virus has evolved over time with new mutations.”

Singh says that as the pandemic progresses, new variants and their sublineages will continue to evolve going forward. Additionally, investigators are beginning to see individuals infected with a combination of two variants, such as Delta and Omicron variants simultaneously.

“Vaccinated individuals or those that have previously tested positive may have the antibodies for one variant but not necessarily for any of the other variants,” Singh says. “The various mutations may seem like only subtle differences, but they are very important.”

Singh says that similar to the influenza virus, the coronavirus is likely never going to vanish from society, but new vaccines can be developed to target the virus’ most up-to-date version. However, with how rapidly the coronavirus has been mutating, the vaccines may become less effective over time.

“The ultimate solution going forward will likely be the development of small molecule, antiviral drugs that target parts of the virus that do not mutate,” Singh says. “While there is no vaccine for HIV, there are very effective antiviral drugs that help those infected live a healthy life, so hopefully the same can be true with COVID-19.”

Recently, Singh, who has tested positive for COVID-19 multiple times himself, helped develop CoroQuil-Zn, a supplement that can be taken while infected with COVID-19 to help reduce one’s viral load. The supplement, which is currently being used by patients in India, southeast Asia, and Great Britain, is awaiting FDA approval for use in the United States.

“I am proud of my team’s efforts, as we have identified specific mutations for various variants throughout the pandemic, and it feels good to be contributing to research that is assisting with the situation,” Singh says. “We will continue to help out, as there will surely be new variants in the future.”

The research appears in the International Journal of Molecular Sciences.

The National Institute of Allergy and Infectious Diseases, the National Strategic Research Institute at the University of Nebraska, and the Christopher S. Bond Life Sciences Center funded the work.

Source: University of Missouri