SARS-CoV-2 Mutations Having Higher Transmission Rates Could Require Yearly COVID-19 Vaccine Shots

New research has found that SARS-CoV-2 is gaining momentum through naturally occurring mutations capable of producing mutant viruses which can escape vaccines or mutants that can resist drugs and other therapies, potentially creating the need for administering COVID-19 vaccine shots on an annual basis.

Molecular analysis of COVID-19’s powerful second wave in Houston from May 12 to July 7 has revealed a mutated virus strain linked to higher transmission and infection rates than the coronavirus strains that caused Houston’s first wave. Gene sequencing results from 5,085 COVID-positive patients tested at Houston Methodist (Houston, TX, USA) since early March has shown a virus capable of adapting, surviving and thriving – making it more important than ever for physician scientists to understand its evolution as they work to discover effective vaccines and therapies.


In the second major gene sequencing study conducted by a team of infectious disease pathologists, they found that the two waves affected different types of patients. The study provides the first molecular characterization of SARS-CoV-2 strains causing two distinct COVID-19 disease waves, a problem now occurring extensively in many European countries. Houston’s second wave hit significantly younger patients who had fewer underlying conditions and were more likely to be Hispanic/Latino living in lower income neighborhoods. In addition, virtually all COVID-19 strains studied during the second wave displayed a Gly614 amino acid replacement in spike protein – the part of the virus that mediates invasion into human cells, gives the coronavirus its telltale crown-like appearance and is the major focus of vaccine efforts worldwide. While this mutation has been linked with increased transmission and infectivity, as well as a higher virus load in the nasopharynx, which connects the nasal cavity with the throat, the mutation did not increase disease severity, researchers said.

The findings reinforce researchers’ concerns of the coronavirus gaining momentum through naturally occurring mutations capable of producing mutant viruses that can escape vaccines - dubbed ‘escapians’ - or mutants that can resist drugs and other therapies. Scientists believe that if coronavirus continues to evolve over time, then the process could impact the effectiveness of COVID-19 vaccines. As the coronavirus changes, COVID-19 vaccines may need to change along with it and new shots incorporating those changes could be administered to the population every year.

“This extensive virus genome data gathered from Houston’s earliest cases to date, coupled with the growing database we are building at Houston Methodist, will help us identify the origins of new infection spikes and waves,” said James M. Musser, M.D., Ph.D., chair of the Department of Pathology and Genomic Medicine at Houston Methodist, who is corresponding author on the study. “This information can be an especially helpful community resource as schools and colleges re-open and public health constraints are further relaxed.”

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