--- description: Find out why Tomas Cihlar and Wesley Sundquist is on the TIME100 Health 2025 list. title: TIME100 Health: Tomas Cihlar and Wesley Sundquist image: https://static.time.com/v3/assets/bltea6093859af6183b/bltb4a753e452338c7a/6998c654e2d64bc244c5f4d4/Tomas-Cihlar-and-Wesley-Sundquist-copy.jpg?branch=production&width=1920&quality=75&auto=webp&crop=16:9 --- May 08, 2025 # Tomas Cihlar and Wesley Sundquist ## Video: TIME100 Health | The Honorees [Watch (HLS stream): TIME100 Health | The Honorees](https://cdn.jwplayer.com/manifests/E3ji9BFs.m3u8) (0:40)  _Published 2025-05-08. Find out why they're on the TIME100 Health list._ Preventing HIV by [Alice Park](/author/alice-park/) ## Alice Park Update your preferences in [Account Settings](/account/preferences/) Close Senior Correspondent  Cindy Ord—Getty Images Decades into the fight against HIV, there is still no vaccine against the virus, though antiretroviral drug treatments have fundamentally transformed it from a deadly disease into a chronic condition that can be effectively managed. Now, thanks to Tomas Cihlar’s and Wesley Sundquist’s contributions, the world is a step closer to preventing infections altogether. Sundquist, a biochemist at the University of Utah, and Cihlar, a virologist at biopharma company Gilead, helped develop lenacapavir, a twice a year shot that could prevent people from getting HIV. Sundquist’s work to understand one of HIV’s proteins, the capsid, which protects the virus’ genome, attracted Cihlar, who visited Sundquist’s lab and took his discovery to Gilead, where the two continued to work for a decade to develop lenacapavir. “We tried a lot of different things, and hit many roadblocks,” says Cihlar. “After 10 years and making more than four thousand molecules and profiling them, we arrived at lenacapavir, which had all the unique properties we were excited about—it had potent activity against HIV that was amazing and off the scale compared to anything that existed at the time.” That potency led to lenacapavir’s approval in 2022 as an injectable HIV treatment that people with HIV needed only twice a year, compared to taking daily pills in the standard treatment regimen. Now, Gilead is studying lenacapavir in people who are not yet infected, but at high risk, to see if the twice yearly injections can prevent them from getting HIV at all. And so far, the results are promising: the latest studies found it was [anywhere](https://www.npr.org/sections/goats-and-soda/2024/12/12/g-s1-37662/breakthrough-hiv-lenacapavir "undefined") from 96% to 100% effective at preventing HIV infection in people at high risk of acquiring HIV. ```json [{"@context":"https://schema.org","@type":"Article","@id":"https://time.com/collections/time100-health-2025/7279660/tomas-cihlar-wesley-sundquist/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/collections/time100-health-2025/7279660/tomas-cihlar-wesley-sundquist/"},"headline":"Tomas Cihlar and Wesley Sundquist","datePublished":"2025-05-08T11:02:00.000Z","dateModified":"2026-03-03T02:29:13.773Z","description":"Find out why they're on the TIME100 Health list.","url":"https://time.com/collections/time100-health-2025/7279660/tomas-cihlar-wesley-sundquist/","keywords":["TIME100Health2025","franchise","Magazine","Special Project","sponsorshipblock","Accolades"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/bltb4a753e452338c7a/6998c654e2d64bc244c5f4d4/Tomas-Cihlar-and-Wesley-Sundquist-copy.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Alice Park","jobTitle":"Senior Correspondent","url":"https://time.com/author/alice-park/"}],"creator":"Alice Park","articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/bltb4a753e452338c7a/6998c654e2d64bc244c5f4d4/Tomas-Cihlar-and-Wesley-Sundquist-copy.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/time100health2025/","name":"TIME100Health2025"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/collections/time100-health-2025/7279660/tomas-cihlar-wesley-sundquist/","name":"Tomas Cihlar and Wesley Sundquist"}}]},{"@context":"https://schema.org","@type":"VideoObject","name":"TIME100 Health | The Honorees","description":"Find out why they're on the TIME100 Health list.","thumbnailUrl":"https://cdn.jwplayer.com/v2/media/E3ji9BFs/poster.jpg?width=720","uploadDate":"2025-05-08T10:30:00.000Z","contentUrl":"https://cdn.jwplayer.com/manifests/E3ji9BFs.m3u8","embedUrl":"https://time.com/collections/time100-health-2025/7279660/tomas-cihlar-wesley-sundquist/","duration":"PT40S","potentialAction":{"@type":"SeekToAction","target":"https://time.com/collections/time100-health-2025/7279660/tomas-cihlar-wesley-sundquist/?jw_start={seek_to_second_number}","startOffset-input":"required name=seek_to_second_number"}}] ```