COVID-19 vaccine manufacturers Pfizer, Moderna and Johnson & Johnson are all testing booster shots that could arrive in United States clinics as early as fall.
Dr. Stephen Feagins, chief clinical officer for Hamilton County Public Health, said boosters and other, long-term COVID-19 remedies become increasingly necessary as portions of the country continue to refuse the vaccine.
“The longer we have a segment of our population who is not vaccinated, a virus can transmit from one to another,” he said Monday afternoon. “And every time it does so, it can change. Thus the variant. If it is a positive change for the virus, then that is going to become the dominant strain.”
To a virus, each vulnerable human body is an incubator for a potential new strain — one that may be more infectious, like the B.1.1.7 variant first recorded in the United Kingdom, more deadly or more resistant to existing treatments.
Feagins said the current vaccines appear to protect against all known variants, including B.1.1.7. However, other variants could eventually threaten fully vaccinated people.
“The longer we have individuals who don't have some type of immunity and for whom transmission has the ability to occur, the continued opportunity for variants continues,” he said.
He envisions the boosters in development as being similar to flu shots: A jab delivered periodically to defend against the latest changes in the virus. He’s not sure how often they’d be given, since the longterm efficacy of the existing vaccines hasn’t been fully tested.
For now, Pfizer, Moderna and J&J all believe their vaccines remain 90% effective six months after delivery, but they’re not sure when or how sharply immunity might fall off.