As the COVID-19 pandemic winds down – for the time being at least – efforts are ramping up to develop next-generation vaccines that can protect against future novel coronaviruses and variants. Several projects are presenting clever combinations of viral parts to the immune system that evoke a robust and hopefully lasting response.
The coming generation of “pan” vaccines aims to tamp down SARS-CoV-2, its closest relatives, and whatever may come into tamer respiratory viruses like the common cold. Whatever the eventual components of this new generation of vaccines, experts agree on the goal: preventing severe disease and death. And a broader approach is critical.
“All the vaccines have been amazing. But we’re playing a whack-a-mole game with the variants. We need to take a step back and ask if a pan-variant vaccine is possible. That’s important because Omicron isn’t the last variant,” said Jacob Lemieux, MD, PhD, instructor in medicine and infectious disease specialist at Massachusetts General Hospital, Boston.
A broad spectrum vaccine
The drive to create a vaccine that would deter multiple coronaviruses arose early, among many researchers. An article published in Nature in May 2020 by National Institute of Allergy and Infectious Diseases researcher Luca T. Giurgea, MD, and colleagues said it all in the title: “Universal coronavirus vaccines: the time to start is now.”
Their concerns? The diversity of bat coronaviruses poised to jump into humans; the high mutability of the spike gene that the immune response recognizes; and the persistence of mutations in an RNA virus, which can’t repair errors.
Work on broader vaccines began in several labs as SARS-CoV-2 spawned variant after variant.
On Sept. 28, NIAID announced funding for developing ‘pan-coronavirus’ vaccines – the quotation marks theirs to indicate that a magic bullet against any new coronavirus is unrealistic. “These new awards are designed to look ahead and prepare for the next generation of coronaviruses with pandemic potential,” said NIAID director Anthony S. Fauci, MD. An initial three awards went to groups at the University of Wisconsin, Brigham and Women’s Hospital, and Duke University.
President Biden mentioned the NIAID funding in his State of the Union Address. He also talked about how the Biomedical Advanced Research and Development Authority, founded in 2006 to prepare for public health emergencies, is spearheading development of new vaccine platforms and vaccines that target a broader swath of pathogen parts.
Meanwhile, individual researchers from eclectic fields are finding new ways to prevent future pandemics.
Artem Babaian, PhD, a computational biologist at the University of Cambridge (England), had the idea to probe National Institutes of Health genome databases, going back more than a decade, for overlooked novel coronaviruses. He started the project while he was between jobs as the pandemic was unfurling, using a telltale enzyme unique to the RNA viruses to fish out COVID cousins. The work is published in Nature and the data freely available at serratus.io.
Among the nearly 132,000 novel RNA viruses Dr. Babaian’s team found, 9 were from previously unrecognized coronaviruses. The novel nine came from “ecologically diverse sources”: a seahorse, an axolotl, an eel, and several fishes. Deciphering the topographies of these coronaviruses may provide clues to developing vaccines that stay ahead of future pandemics.
But optics are important in keeping expectations reasonable. “‘Universal vaccine’ is a misnomer. I think about it as ‘broad spectrum vaccines.’ It’s critical to be up front that these vaccines can never guarantee immunity against all coronaviruses. There are no absolutes in biology, but they hopefully will work against the dangers that we do know exist. A vaccine that mimics exposure to many coronaviruses could protect against a currently unknown coronavirus, especially if slower-evolving antigens are included,” Dr. Babaian said in an interview.
Nikolai Petrovsky, MD, PhD, of Flinders University, Adelaide, and the biotechnology company Vaccine Pty, agrees, calling a literal pan-coronavirus vaccine a “pipe dream. What I do think is achievable is a broadly protective, pan–CoV-19 vaccine – I can say that because we have already developed and tested it, combining antigens rather than trying just one that can do everything.”