U.S. Infectious Disease Treatment Market

Gilead Sciences sold USD 5.26 billion of HIV medicines in the United States in the third quarter of 2026, including USD 294 million of Yeztugo, the twice-yearly lenacapavir injection for HIV prevention, its results of 29 October 2026 show, while its COVID-19 antiviral Veklury fell 69% to USD 86 million. American spending on anti-infectives is moving from pandemic drugs to long-acting HIV medicines and new oral antibiotics. The U.S. infectious disease treatment market covers prescription anti-infective medicines used in the United States: HIV antiretrovirals for treatment and prevention, antibacterials, hepatitis and other antivirals including COVID-19, influenza and cytomegalovirus drugs, antifungals, antimycobacterials and antiparasitics, valued at net manufacturer selling prices. Douglas Insights sizes it at USD 45.4 billion in 2025, from about 268.5 million treatment courses at an average USD 169 each, and at USD 60.2 billion in 2035, a revenue CAGR (compound annual growth rate) of 2.86%. The study is the United States share of the matching row in our worldwide Infectious Disease Treatment Market report, sits beside our Hospital Acquired Infection Testing Kit Market and Microbiome Therapeutics Market studies inside our healthcare coverage, and every figure follows the Douglas Insights research methodology.

Which drug classes earn the most in U.S. infectious disease treatment: HIV antiretrovirals, antibacterials or antivirals?

HIV antiretrovirals earn the most U.S. infectious disease treatment value, 57.0% of 2025, USD 25.9 billion, a Douglas Insights estimate. Antifungals grow fastest, 3.40% a year, from USD 2.27 billion to USD 3.17 billion by 2035.

HIV antiretrovirals lead at USD 25.9 billion, well above their 27.9% share in our worldwide model, because American patients are treated with branded single-tablet and injectable regimens at high net prices, while most of the world uses generic tablets. They grow 3.00% a year to USD 34.8 billion as pre-exposure prophylaxis (PrEP) spreads and long-acting injections replace daily pills, held back from 2028 by Medicare price talks. Antibacterials, USD 10.2 billion or 22.5%, grow 2.60%: most antibiotic courses are cheap generics, but new oral drugs for resistant urinary infections and gonorrhoea add value at the top, a Douglas Insights estimate.

Hepatitis and other antivirals, USD 5.22 billion, grow only 1.60% a year because COVID-19 antiviral sales keep falling and hepatitis C cures shrink the pool of untreated patients each year. Antifungals, USD 2.27 billion, grow fastest at 3.40% as more patients receive cancer treatment and transplants that weaken the immune system. Antiparasitics and antimalarials hold USD 1.13 billion and antimycobacterials, mainly tuberculosis and nontuberculous mycobacterial drugs, USD 681 million. Class values for 2035 sum to USD 59.5 billion, 1.13% below the USD 60.2 billion headline, inside our 2.5% tolerance. Drugs that restore gut bacteria after antibiotics are sized in our Microbiome Therapeutics Market report.

Spend by care setting and channel

By care setting, community infections treated outside hospitals carry about 71% of 2025 value, USD 32.2 billion, because HIV treatment and prevention are filled at retail and specialty pharmacies, and hospital-treated infections about 29%, USD 13.2 billion, Douglas Insights estimates. By channel, retail and specialty pharmacies carry about 68%, hospital pharmacies 29% and public programmes and tenders about 3%.

What drives U.S. infectious disease treatment spend up 2.86% a year?

U.S. infectious disease treatment spend grows 2.86% a year because treatment courses add 1.60% and price per course adds 1.24%, lifting the average course from USD 169 in 2025 to about USD 191 in 2035, Douglas Insights estimates.

Three forces lift spend, all Douglas Insights estimates unless a source is linked: long-acting HIV medicines add about 1.35 points, new antibiotics for resistant infections about 0.45 points, and an ageing, more immunocompromised population about 1.05 points, which sum to the 2.86% rate after 0.01 points of rounding. Each is set out below.

Long-acting HIV prevention and treatment: 1.35 points

Long-acting HIV medicines add 1.35 points. The US Food and Drug Administration (FDA) approved Yeztugo, lenacapavir given every six months for HIV prevention, on 18 June 2025, Gilead’s approval release states. Gilead’s total HIV sales rose 18% to USD 6.25 billion in the third quarter of 2026 and Descovy, its daily PrEP pill, rose 49% to USD 1.05 billion, its results of 29 October 2026 show. ViiV Healthcare, majority-owned by GSK, grew U.S. HIV sales 13% to GBP 1.52 billion in the same quarter, with Cabenuva at GBP 478 million and Apretude at GBP 143 million worldwide, GSK’s third-quarter announcement of 28 October 2026 shows. Long-acting injectables made up 35% of ViiV’s U.S. HIV sales in the second quarter of 2026, GSK’s Form 6-K states.

New antibiotics for resistant infections: 0.45 points

New antibiotics add 0.45 points. The FDA approved GSK’s Blujepa (gepotidacin), the first new class of oral antibiotics for uncomplicated urinary tract infections in nearly 30 years, in March 2025, GSK’s release of 25 March 2025 states, and on 11 December 2025 approved Blujepa and Innoviva’s single-dose Nuzolvence (zoliflodacin) for urogenital gonorrhoea, the FDA’s announcement reports. GSK’s Utebzi (tebipenem pivoxil), the first oral carbapenem approved in the country, for complicated urinary tract infections, followed in June 2026, GSK’s release of 17 June 2026 states, with availability expected by the end of 2026. An oral carbapenem can send a patient home instead of keeping them on an intravenous drip.

Ageing and immunocompromised patients: 1.05 points

The last 1.05 points come from patients. Americans aged 65 and over, people on cancer treatment and transplant recipients get more serious bacterial and fungal infections and need longer, dearer courses. Carbapenem-resistant infections carrying the NDM enzyme rose more than 460% between 2019 and 2023, the Centers for Disease Control and Prevention (CDC) reported on 23 September 2025, and few existing drugs treat them. Together, (1.0160 x 1.0124) minus 1 gives the 2.86% revenue rate.

What holds back U.S. infectious disease treatment: COVID decline, Medicare price talks or generic antibiotics?

Three restraints slow U.S. infectious disease treatment spend: falling COVID-19 antiviral sales, Medicare drug price negotiation, and cheap generic antibiotics that leave little money for new ones, Douglas Insights estimates.

COVID-19 antivirals are the largest drag. Gilead’s Veklury fell 69% to USD 86 million in the third quarter of 2026 and Gilead expects about USD 300 million for the whole year, against USD 911 million in 2025, its third-quarter release and full-year release of 10 February 2026 show. Merck’s Lagevrio earned only USD 17 million in the third quarter, its Form 10-Q shows. We take about 0.35 points a year off the antivirals class until 2028.

Medicare price talks take about 0.30 points a year. The Centers for Medicare & Medicaid Services (CMS) agreed a price of USD 1,000 for a 30-day supply of Xifaxan (rifaximin), against a USD 2,696 list price, a 63% cut from 1 January 2027, its negotiated price fact sheet shows, and on 27 January 2026 it picked Biktarvy, with USD 3.90 billion of Medicare spending and 101,000 enrollees, for prices from 2028, its selected drug list shows. Generic antibiotics take the rest: most courses cost a few dollars, so hospitals and insurers resist paying for new drugs, a Douglas Insights estimate. These restraints are already netted into the 1.60% course leg and 1.24% price leg above. How hospitals detect the infections these drugs treat is covered in our Hospital Acquired Infection Testing Kit Market report.

Where in the United States is infectious disease treatment spend highest: the South, West, Northeast or Midwest?

The South spends the most, USD 17.7 billion or 39.0% of 2025 U.S. infectious disease treatment value, a Douglas Insights estimate, and grows fastest, 3.20% a year, to USD 24.2 billion by 2035.

We count value where the patient is treated. The South leads because it has the largest population and about half of new HIV diagnoses, a Douglas Insights estimate, so it buys the largest share of antiretrovirals and PrEP; it grows 3.20% a year as Florida, Texas, Georgia and the Carolinas add residents and PrEP use rises. CDC counted nearly 39,000 new HIV diagnoses nationally in 2024 and more than 1.2 million people living with HIV, its surveillance update of 18 May 2026 shows. The West, USD 10.4 billion, grows 2.80% on California’s large HIV treatment programmes and an ageing population.

The Northeast, USD 8.62 billion, grows 2.50%: New York and Massachusetts have high HIV treatment coverage and many academic hospitals that use the newest antibiotics and antifungals, but the region adds few residents. The Midwest, also USD 8.62 billion, grows 2.50% on hospital antibiotic and antifungal use in large health systems in Illinois, Ohio and Michigan. Regional values sum to USD 46.7 billion in 2026, 0.02% below the headline, and USD 60.1 billion in 2035, 0.13% below it; in the data table the row labelled Global holds the United States total.

Who leads U.S. infectious disease treatment: Gilead, ViiV Healthcare or Merck?

Gilead Sciences holds the largest share of U.S. infectious disease treatment value, about 43.5% of 2025, USD 19.7 billion, Douglas Insights estimates. With ViiV Healthcare and Merck the top three hold about 64.5%.

The shares are Douglas Insights estimates because companies do not split U.S. anti-infective sales by class in one place. Gilead’s HIV sales were USD 20.75 billion worldwide in 2025, with Biktarvy at USD 14.3 billion, its full-year release states; in the third quarter of 2026 its U.S. HIV sales of USD 5.26 billion were 84% of its HIV total, and Biktarvy earned USD 3.28 billion in the United States, its third-quarter release shows. ViiV’s HIV sales reached GBP 7.69 billion worldwide in 2025, up 8%, with Dovato at GBP 2.68 billion, GSK’s full-year Form 6-K shows.

AbbVie brought Emblaveo (aztreonam-avibactam) to the U.S. market after FDA approval for complicated intra-abdominal infections with limited or no treatment options, its release of 7 February 2025 states. Competition in HIV turns on long-acting dosing: Gilead sells a six-monthly prevention shot, while ViiV sells two-monthly injections for treatment and prevention. In antibiotics, large firms that sell many medicines, such as GSK, can carry a new drug through its slow early years; small antibiotic makers often cannot.

What does a course of anti-infective treatment cost in the United States?

A U.S. anti-infective treatment course averaged about USD 169 at net prices in 2025, Douglas Insights estimates, from a few dollars for a generic antibiotic to over USD 40,000 a year for branded HIV treatment.

The bands are Douglas Insights estimates of net prices after rebates, except the Xifaxan figure, which CMS published in its negotiated price fact sheet for 2027. The average is low because about 9 in 10 courses are short generic antibiotic or antiviral courses, while a small number of HIV patients account for more than half of the value. Price per course rises 1.24% a year, to about USD 171 in 2026 and USD 191 in 2035, as long-acting and branded drugs gain share; Medicare negotiation for Biktarvy from 2028 holds the rise down. Patented drug tariffs do not reach generic antibiotics for now: the White House exempted generics and biosimilars from the pharmaceutical tariffs announced on 2 April 2026, to be reassessed after a year, its fact sheet states.

Which rules shape U.S. infectious disease treatment: Medicare negotiation, the PASTEUR Act or Section 232 drug tariffs?

Three rule sets shape U.S. infectious disease treatment: Medicare drug price negotiation under the Inflation Reduction Act, the PASTEUR Act proposal to pay for new antibiotics by subscription, and the Section 232 tariffs on patented medicines.

Medicare negotiation has reached the class twice: Xifaxan’s negotiated price applies from 1 January 2027, CMS’s 2027 fact sheet shows, and Biktarvy, the country’s largest HIV medicine, was selected on 27 January 2026 for prices from 2028, CMS’s 2028 list shows. We model a cut to Biktarvy’s Medicare net price from 2028 that removes about USD 0.8 billion a year from HIV value, a Douglas Insights estimate.

The PASTEUR Act would pay antibiotic makers through contracts that do not depend on how many courses they sell. The House bill, H.R. 7352, was introduced on 4 February 2026 and would appropriate USD 6 billion, its bill text shows, and Senators Todd Young and Michael Bennet reintroduced the Senate version on 24 June 2026, Senator Young’s release states. We do not assume it passes in our base case. Section 232 tariffs of 100% on patented medicines, cut to 15% for several trading partners and to zero for companies with pricing and onshoring deals, were announced on 2 April 2026, the White House’s fact sheet states; most large anti-infective makers have such deals or local plants, so we add no tariff cost to prices.

What if PrEP use stalls or the PASTEUR Act passes: where does U.S. infectious disease treatment land in 2035?

The U.S. infectious disease treatment market ends 2035 between USD 52.7 billion and USD 68.8 billion across our three cases, around a base of USD 60.2 billion. HIV prevention uptake and antibiotic funding set most of the spread.

In the slower case federal HIV prevention funding falls, PrEP use stalls and Medicare cuts for HIV drugs go deeper than we assume, taking 0.70 points off courses and 0.64 points off price. In the faster case the PASTEUR Act passes, long-acting PrEP reaches several hundred thousand more users and new antifungals launch, adding 0.70 points to courses and 0.66 points to price. One extra point of yearly revenue growth adds about USD 6.11 billion to 2035 value; one point less removes about USD 5.60 billion.

Our 2.86% sits below the 3.32% in our worldwide Infectious Disease Treatment Market report, because poorer countries add treated patients faster, while U.S. growth depends on prices that Medicare now negotiates.

Douglas Exclusive: the HIV Long-Acting Shift Ledger

The HIV Long-Acting Shift Ledger is a Douglas Insights model built from 8 inputs in 6 company and government documents dated June 2025 to October 2026. It tracks how fast HIV spending moves from daily pills to injections.

The finding, a Douglas Insights estimate: long-acting injections for treatment and prevention made up about 14% of combined Gilead and ViiV U.S. HIV sales in the third quarter of 2026, about USD 1.01 billion of USD 7.30 billion, while Yeztugo did not exist before June 2025. We apply ViiV’s 35% second-quarter injectable share, from GSK’s second-quarter Form 6-K to its third-quarter U.S. sales, take Gilead’s Yeztugo sales from its third-quarter release, and convert pounds at USD 1.34. Injections cost about as much per patient-year as daily pills, so the shift adds value mainly by bringing in new PrEP users rather than by raising prices.

The ledger changes how to read the market. When Medicare negotiates Biktarvy from 2028, the daily pill base faces a price cut, while six-monthly and two-monthly injections are not yet on any negotiation list. Companies that move patients to long-acting medicines before 2028 protect more of their HIV revenue; we expect injections to reach about a quarter of U.S. HIV value by 2030.

How does the methodology turn 268.5 million treatment courses into USD 45.4 billion of U.S. infectious disease treatment?

Our methodology multiplies about 268.5 million anti-infective treatment courses used in the United States in 2025 by an average USD 169 a course to reach USD 45.4 billion. Courses and prices come from class builds.

The model covers 4 census regions, 6 drug classes, 2 care settings and 3 channels, and uses 104 data points, 23 sourced and 81 modelled. HIV patient-years are counted as courses. Pound figures are converted at USD 1.34, the Douglas Insights 2026 average. Arithmetic: 268.5 million x USD 169 = USD 45.38 billion; USD 45.38 billion x (1.0160 x 1.0124)^10 = USD 60.16 billion, the USD 60.2 billion headline. Courses reach about 272.8 million in 2026 and 314.7 million in 2035; price reaches about USD 171 in 2026; 2026 value is USD 46.7 billion.

Two cross-checks agree. First, the parent row of our worldwide Infectious Disease Treatment Market model that contains the United States is USD 49.3 billion in 2025 and USD 65.4 billion in 2035, and our figure is 92.0% of it in both years. Second, Gilead’s 84% U.S. share of HIV sales in the third quarter of 2026, applied to its USD 20.75 billion 2025 HIV sales, gives about USD 17.4 billion, and ViiV’s 70% U.S. share in the first nine months of 2026, applied to its GBP 7.69 billion 2025 HIV sales, gives about USD 7.19 billion, per the company releases linked above; together USD 24.6 billion, 95% of our USD 25.9 billion HIV class value, with Johnson & Johnson and Merck holding most of the rest. AI tools help draft the text and automated checks test the arithmetic and links; the Douglas Insights research desk chooses the sources, builds the model and approves publication, as our editorial standards explain.

Sources

1. Gilead Sciences Gilead Sciences announces third quarter 2026 financial results (2026)
2. Gilead Sciences Gilead Sciences fourth quarter and full year 2025 financial results (2026)
3. Gilead Sciences Yeztugo approved by FDA for HIV prevention (2025)
4. GSK GSK Q3 2026 results announcement (2026)
5. GSK / SEC GSK Form 6-K, Q2 2026 (2026)
6. GSK / SEC GSK Form 6-K, full year 2025 (2026)
7. GSK Blujepa approved by US FDA for uncomplicated urinary tract infections (2025)
8. US Food and Drug Administration FDA approves two oral therapies to treat gonorrhea (2025)
9. GSK Utebzi FDA approval (2026)
10. AbbVie FDA approves Emblaveo (2025)
11. Centers for Medicare & Medicaid Services Negotiated prices for initial price applicability year 2027 (2025)
12. Centers for Medicare & Medicaid Services Selected drug list for initial price applicability year 2028 (2026)
13. Centers for Disease Control and Prevention CDC report finds sharp rise in dangerous drug-resistant bacteria (2025)
14. Centers for Disease Control and Prevention 2024 HIV surveillance data (2026)
15. Merck / SEC Merck Form 10-Q, quarter ended 30 September 2026 (2026)
16. GovInfo H.R. 7352, PASTEUR Act of 2026 (2026)
17. The White House Fact sheet: tariffs on patented pharmaceutical products (2026)

What counts in the U.S. infectious disease treatment market, and what is excluded?

The U.S. infectious disease treatment market counts prescription anti-infective medicines used in the United States, valued at net manufacturer prices. Vaccines, monoclonal antibodies for prevention, diagnostics, disinfectants and over-the-counter products are excluded.

The by-class split covers the six drug classes above; the by-care-setting split covers hospital-treated and community infections; the by-channel split covers hospital pharmacies, retail and specialty pharmacies, and public programmes; the by-region split covers the four census regions. Value is counted where the patient is treated. Injectable medicines that use lipid carriers, including liposomal antifungals, are sized in our Liposome Injection Market report.