Stanford Health Care (SHC) is offering Pfizer-BioNTech COVID-19 booster shots as of Sept. 27 in line with new vaccination guidelines issued by the Centers for Disease Control and Prevention (CDC) last month. 17,864 total doses have been administered as of Tuesday, according to SHC spokesperson Julie Greicius.

The booster shots are being offered to established SHC patients who received their second dose of the Pfizer vaccine at least six months ago and are either over the age of 65, residents of long-term care facilities, work in high-risk occupational settings or immunocompromised, according to the SHC COVID-19 vaccination website. 

“There is no wait list for the Pfizer/BioNTech booster shot; appointments are readily available and drop-ins are welcome,” Greicius wrote in a statement to The Daily.

On Wednesday, the FDA also authorized the use of the Moderna and Johnson & Johnson vaccines as booster doses through a “mix and match” approach, though SHC has not yet released information on the offering of these boosters.

The Pfizer-BioNTech booster shot is identical in makeup to the original vaccine and serves to strengthen the body’s resistance to infection, according to medicine professor Dean Winslow. 

“The immune system in healthy individuals responds more robustly after being initially ‘primed’ by either natural infection or an earlier dose of a vaccine,” Winslow wrote in an email to The Daily. “A booster results in augmentation of the initial immune response.”

Winslow said that while patients under the age of 65 who are immunocompromised or work in high-risk occupational settings are receiving the booster at SHC, he does not recommend the booster for healthy patients under 65.  

“Since the threat of disease is very rare in otherwise healthy people under 65, I am not recommending that younger people get a booster at this time unless they fall into one of these high risk categories,” Winslow wrote.

University spokesperson E.J. Miranda declined to comment on how many Stanford students, faculty and staff have received the booster shot thus far. Miranda wrote in a statement that “the University will continue to monitor CDC, state and county guidance and adjust health and safety protocols as conditions evolve and provide updates to the university community.”

Appointments for the booster shot can be scheduled online through SHC’s MyHealth portal. Beyond SHC, booster shots are also available at various locations across Santa Clara County, including clinics and pharmacies in San Jose, Livermore, Morgan Hill, Cupertino, Sunnyvale and Mountain View.