All three licensed HPV vaccines are non-infectious L1 virus-like particle vaccines. Since 2016, 9vHPV has replaced the bivalent and quadrivalent products as the sole HPV vaccine distributed in the US. In Singapore, 9vHPV (Gardasil 9) joins the national immunisation schedules and subsidised vaccine list from 1 January 2027.
| Bivalent (2vHPV, Cervarix) | Quadrivalent (4vHPV, Gardasil) | 9-Valent (9vHPV, Gardasil 9) | |
|---|---|---|---|
| HPV types covered | 16, 18 | 6, 11, 16, 18 | 6, 11, 16, 18, 31, 33, 45, 52, 58 |
| Licensed population | Females only | Females and males | Females and males |
| Disease protection | Cervical, vulvar and vaginal precancer/cancer (CIN I–III) | Adds genital warts, plus cervical, vulvar, vaginal and anal precancer/cancer | Broadest coverage: adds protection against oropharyngeal cancer, along with genital warts and precancer/cancer at cervical, vulvar, vaginal and anal sites |
| Share of cervical cancers covered | ~66–70% | ~66–70% | ~90% |
| US availability | Discontinued; not distributed since 2016 | Discontinued; not distributed since 2016 | Only HPV vaccine currently available in the US |
| Singapore status (from 1 Jan 2027) | Remains on the national schedules as an alternative option | No longer available in Singapore; removed from the national schedules | Added to the national schedules and subsidised vaccine list |
Singapore: What Changes from 1 January 2027
In a joint statement on 2 October 2026, the Ministry of Health (MOH), Health Promotion Board (HPB) and the Communicable Diseases Agency (CDA) announced that Gardasil 9 (HPV9) will be added to Singapore’s national immunisation schedules and subsidised vaccine list from 1 January 2027.[6]
Schedules and subsidies
- HPV9 is being added to the National Childhood Immunisation Schedule (NCIS) and the National Adult Immunisation Schedule (NAIS) for females aged 9 to 26.[6]
- HPV2 (Cervarix) stays on both schedules as an alternative option. HPV4 (previously Gardasil) is no longer available in Singapore and has been removed from the schedules.[6]
- Eligible Singaporean adults can receive means-tested subsidies of up to 75% for HPV9. Permanent residents can receive subsidies at polyclinics.[6]
- Eligible Singaporean children can receive full subsidies at CHAS GP clinics and polyclinics.[6]
Updated dosing recommendations (Expert Committee on Immunisation)
- Ages 9 to 14: two doses for girls receiving their first dose of either HPV2 or HPV9.[6]
- Ages 15 to 26: three doses for those receiving their first dose.[6]
- Over 26: if a series was started but not completed by age 26, the remaining doses may be completed after this age, as early as possible, up to age 45.[6]
- Unvaccinated females aged 27 to 45: may start or complete a series with HPV2 or HPV9 if they wish. However, the CDA has said there is currently no NAIS recommendation for this group to start vaccination, because population-level evidence of efficacy in this age group is limited.[6]
Patients who started with HPV2 or HPV4
Patients who started with HPV2 or HPV4 and have doses pending may complete the series with HPV9. The agencies note that studies show mixed schedules are safe and protect against the strains covered by both vaccines. Those who have already completed their series do not need additional doses.[6]
School-based HPV vaccination programme
- HPV9 will replace HPV2 in HPB’s school-based immunisation programme for Secondary 1 and 2 female students, provided at no charge.[6]
- Students who received HPV2 as their first dose in 2026 and have not completed the series will be scheduled to receive HPV9 as their second dose in 2027.[6]
- Female students who have already completed their series are not eligible for further HPV9 doses, in line with the ECI’s recommendations.[6]
Practice Guidelines (US: ACOG and ACIP)
The American College of Obstetricians and Gynecologists (ACOG) recommends that the HPV vaccine series not be restarted regardless of delays between doses. Any available HPV vaccine product may be used to continue or complete a series for protection against HPV 16/18 in women when the original product is unknown, unavailable, or during a transition to 9-valent vaccine. For men, either the 9-valent or quadrivalent vaccine may be used to continue or complete the series.[1]
Revaccination with the 9-valent HPV vaccine after a completed three-dose series of bivalent or quadrivalent vaccine is not a routine recommendation. The bivalent and quadrivalent vaccines are already highly effective against HPV-related disease, and current data on durability of immune response give no indication for a booster dose.[1]
The three licensed HPV vaccines differ by valency and target genotypes, not by mechanism: all are non-infectious L1 virus-like particle vaccines.[3][4]
HPV 16 and 18 account for roughly 66% of cervical cancers and are covered by all three vaccines. The five additional types in 9vHPV account for an additional ~15% of cervical cancers, translating to an estimated 3,800 additional HPV-associated cancers prevented annually in the US, the large majority in women.[4]
Counseling patients who started with 2vHPV or 4vHPV and want to complete with 9vHPV
The Advisory Committee on Immunization Practices (ACIP) explicitly states that 9vHPV may be used to continue or complete a series begun with 2vHPV or 4vHPV, and the series does not need to be restarted. Dosing intervals are based on age at the first dose, not product switches.[4][5]
For patients who already completed a full series with 2vHPV or 4vHPV, there is no ACIP recommendation for additional 9vHPV doses.[4][5] If a patient who completed a 4vHPV series wants added protection against the five extra oncogenic types, counseling should note that:
- The benefit is largely limited to females (cervical cancer/precancer prevention), since few male HPV-associated cancers are caused by these additional types.[4]
- Cervical cancer screening per standard guidelines remains necessary regardless of vaccination status.[4]
- Available safety data on receiving 9vHPV after a completed 4vHPV series show no serious safety concerns.[4]
References
- Human Papillomavirus Vaccination: ACOG Committee Opinion, Number 809. Obstetrics and Gynecology. 2020;136(2):e15-e21. doi:10.1097/AOG.0000000000004000.
- Human Papillomavirus Vaccination. Committee on Adolescent Health Care. American College of Obstetricians and Gynecologists. 2020.
- Comparison of different human papillomavirus (HPV) vaccine types and dose schedules for prevention of HPV-related disease in females and males. Bergman H, Buckley BS, Villanueva G, et al. Cochrane Database of Systematic Reviews. 2019. doi:10.1002/14651858.cd013479.
- Supplemental information and guidance for vaccination providers regarding use of 9-valent HPV. Advisory Committee on Immunization Practices (2016).
- Use of a 2-Dose Schedule for Human Papillomavirus Vaccination: Updated Recommendations of the Advisory Committee on Immunization Practices. Meites E, Kempe A, Markowitz LE. MMWR Morb Mortal Wkly Rep. 2016;65(49):1405-1408. doi:10.15585/mmwr.mm6549a5.
- Eligible women in Singapore to get subsidised access to broader HPV9 vaccine from 2027 (reporting on the MOH, HPB and CDA joint statement of 2 Oct 2026). The Straits Times. straitstimes.com.
For clinician reference only. Singapore details are as reported on 2 October 2026; please check MOH, HPB and CDA for the latest guidance.