People of all ages rely on vaccines to avoid or lessen the impact of painful and life-threatening infectious diseases, such as flu, shingles, or COVID-19.

What they may not realize is how much research goes into developing new vaccines, and making sure the existing shots are working well.

That’s where the Kaiser Permanente Vaccine Study Center comes in.

For 30 years, the Oakland-based center’s researchers have carried out studies on various topics related to vaccine development, safety, and effectiveness. Because of the team’s access to the health histories of millions of Kaiser Permanente patients, its researchers also have a unique view of the long-term, real-world experience with approved and widely used vaccines.

Recent published research on the shingles vaccine

Most recently, the center reported important findings about vaccines that protect against the varicella-zoster virus, which causes chickenpox in children and can reactivate in adults as a painful shingles rash.

A research study published in January and led by the Vaccine Study Center showed that the current shingles vaccine – Shingrix, which comes in 2 doses and uses recombinant technology – offered strong protection and remained effective for more than 4 years.

The research relied on data from 2 million patients, including those from Kaiser Permanente Northern California, two other Kaiser Permanente regions, and from the Marshfield Clinic in Wisconsin. The health systems share information through the Vaccine Safety Datalink, a project supported by the Centers for Disease Control and Prevention.

Monitoring real-world use of vaccines adds to what is known from the initial clinical trials that were used to approve them, said Vaccine Study Center Director Nicola Klein, MD, PhD, a research scientist with the Kaiser Permanente Division of Research.

“The Vaccine Study Center has multiple roles in vaccine development and use, but our ability to study real-world use of vaccines over time, with large, diverse populations, is a unique contribution to the field,” she said.

In 2023, the center reported on an earlier shingles vaccine, Zostavax, which is no longer used in the U.S., but is used in other parts of the world. The study confirmed that its effectiveness waned significantly over time, which is why this vaccine was discontinued in this country. The study looked at 10 years of experience with Zostavax in Kaiser Permanente patients in Northern California.  

Staying ahead of flu

The center also contributes to the ongoing and challenging effort to stay ahead of influenza virus strains because they mutate regularly. The center researchers also evaluate available flu vaccines, which vary by dose and by the technology used to make them.

Most recently, researchers published an evaluation of the high-dose, recombinant vaccine Flublok in older adults, using data from Kaiser Permanente patients in Northern California.

A unique aspect of the study was that it used a weekly alternating randomized design, giving adult patients aged 18-64 either Flublok or the standard-dose vaccine during the 2018-2021 flu seasons. It found about 15% increased protection for adults aged 50 to 64 from Flublok.

Such innovative research approaches are needed to understand vaccine effectiveness with a virus such as flu, because it’s difficult for public health officials to choose the strains to put in the vaccine each year. The strains must match what is circulating that season to work well. Flu vaccine effectiveness can vary from 20% to 60%, Dr. Klein said.

“It is clear that research into more consistently effective flu vaccines is needed,” she said. “This is one of the main areas of work for our Vaccine Study Center.”