FDA's approval of the world's first vaccine against RSV will offer a new tool in an old fight – 4 questions answered
The new shot represents six decades of starts and stops in the hunt for a vaccine to curb one of the most common winter respiratory viruses.
- The new shot represents six decades of starts and stops in the hunt for a vaccine to curb one of the most common winter respiratory viruses.
- The vaccine, called Arexvy, made by the biopharmaceutical company GSK, is approved for use in adults ages 60 and over.
- The Conversation asked Annette Regan, an epidemiologist and vaccine specialist, to discuss the significance of the first vaccine against RSV and the other RSV vaccine candidates that are in the pipeline.
1. How does the new vaccine protect against the virus?
- The vaccine targets a protein known as RSV F glycoprotein, which is found on the surface of the virus.
- The vaccine also includes an adjuvant, a substance that helps amplify the effect of the vaccine by boosting the immune system’s response.
2. When and for whom will it be available?
- The committee is expected to meet in June 2023 to make a recommendation on the new RSV vaccine, after which the CDC would officially endorse it.
- It could recommend the vaccine for all adults 60 and older, or a subset of older adults.
- Given the lower efficacy for adults ages 80 and older, the committee could place an age cap on the recommendations.
3. Why has the first RSV vaccine been so long in coming?
- One problem that has plagued vaccine manufacturers is the difficulty of identifying an antigen – the piece of the virus that the vaccine targets – that doesn’t change, or shape-shift.
- The F protein of the RSV virus is notorious for changing its shape once it fuses with a host’s cell.
- Early attempts to create an inactivated RSV vaccine in the 1960s were stalled after they caused an enhanced form of RSV disease.
4. What other RSV vaccine candidates are coming down the line?
- The next RSV vaccine under review with the FDA is Pfizer’s RSV vaccine.
- It is similar to the recently approved vaccine except that it has no adjuvant and is bivalent, meaning that it targets both RSV A and RSV B – the two strains of RSV.
- The CDC advisory committee is scheduled to discuss vaccine recommendations in October 2023, making this the likely next possible vaccine available.