In short
This article summarizes several clinical trials investigating Arexvy, a new vaccine developed by GlaxoSmithKline to prevent respiratory syncytial virus (RSV) infections in adults. Arexvy contains a recombinant RSV protein called PreF3 and an adjuvant system called AS01E to boost immune responses. The trials are evaluating the safety, immune responses, and effectiveness of Arexvy in different adult populations, including healthy older adults, adults with increased risk factors, and immunocompromised patients. Key aspects being studied include optimal dosing schedules, co-administration with other vaccines, and protection against RSV disease.
What is Arexvy?
Arexvy is a new vaccine developed to prevent respiratory syncytial virus (RSV) infections in adults. It was created by GlaxoSmithKline and received approval for use in the European Union in 2023. The vaccine's full name is "Respiratory Syncytial Virus Vaccine (recombinant, adjuvanted)" and it is also known by the code name RSVPreF3 OA.
RSV is a common respiratory virus that usually causes mild, cold-like symptoms. However, it can be serious for infants and older adults. RSV is a leading cause of hospitalization in infants and can cause severe illness in older adults, especially those with chronic heart or lung disease.
How Does Arexvy Work?
Arexvy is a subunit vaccine, which means it contains specific parts of the RSV virus rather than the whole virus. Specifically, it contains:
- A recombinant form of the RSV F protein, which is found on the surface of the virus
- An adjuvant called AS01E, which helps boost the immune response to the vaccine
The vaccine works by stimulating the body's immune system to produce antibodies against the RSV F protein. These antibodies can then recognize and fight off RSV if the vaccinated person is exposed to the virus in the future.
Who is Arexvy For?
Arexvy is currently approved in the European Union for adults 60 years of age and older. This age group is at higher risk for severe RSV disease.
Research is ongoing to evaluate the vaccine's use in other populations, including:
- Adults 18-49 years old who are at increased risk for RSV disease due to underlying medical conditions
- Immunocompromised patients aged 18 years and older
Effectiveness
Clinical trials have shown that Arexvy is effective at stimulating an immune response against RSV. The vaccine produces:
- Neutralizing antibodies against both major subtypes of RSV (RSV-A and RSV-B)
- RSVPreF3-specific binding antibodies
- RSV-specific T cell responses
In adults 60 years and older, a single dose of Arexvy produced a strong immune response that persisted for at least 12 months after vaccination.
Dosing
Arexvy is given as an intramuscular injection, typically in the upper arm. The standard dose is 0.5 mL.
For most adults 60 years and older, a single dose is recommended. However, some ongoing studies are evaluating different dosing schedules, including:
- Annual revaccination
- Revaccination after 2-3 years
- Two-dose primary series for certain immunocompromised patients
The optimal timing and frequency of vaccination are still being determined through ongoing research.
Safety and Side Effects
Clinical trials have shown that Arexvy is generally safe and well-tolerated. The most common side effects are similar to those seen with other vaccines and include:
- Pain at the injection site
- Fatigue
- Headache
- Muscle pain
These side effects are usually mild to moderate and resolve within a few days.
As with any vaccine, there is a small risk of severe allergic reaction (anaphylaxis). People with a history of severe allergic reactions to any component of Arexvy should not receive the vaccine.
Ongoing Research
Several clinical trials are currently underway to further evaluate Arexvy, including:
- Studies on long-term effectiveness and the potential need for booster doses
- Research on co-administration with other vaccines, such as COVID-19 vaccines
- Trials in specific populations like immunocompromised patients
- Studies to determine the optimal vaccination schedule
These ongoing studies will help provide more information on how to best use Arexvy to protect against RSV.