We thank Dr Tay Eng Hseon for his support for the school-based human papilloma virus (HPV) vaccination programme (Offering best protection for S'pore girls, March 13).

The move to offer free vaccination to all Secondary 1 girls in national schools, including madrasahs, is part of the Ministry of Health's (MOH) efforts to increase the coverage of this vaccine which prevents cervical cancer.

While all three HPV vaccines that are available in Singapore - Cervarix, Gardasil, and Gardasil 9 - were considered for the school-based programme, Cervarix was selected following an assessment which included considerations of efficacy, price and stock availability.

Cervarix and the vaccine Gardasil are recommended under the national immunisation schedules, and have been assessed by MOH to be safe and effective in preventing cervical cancer.

The current evidence indicates that both these vaccines provide comparable protection against two of the most common cervical cancer-causing HPV types - HPV types 16 and 18.

They account for 70 per cent of all cervical cancer cases.

While Gardasil extends protection against HPV types 6 and 11, these HPV types generally do not cause cervical cancer.

A third vaccine, Gardasil 9, is relatively new in Singapore and is not included in the national immunisation schedules.

But MOH may offer Gardasil 9 in the school programme in future if it is cost-effective.

The Health Promotion Board will provide parents with educational material on HPV vaccination, the type of vaccines available in Singapore and what will be administered to the girls in schools to encourage parents to opt in for the programme.

Lim Siok Peng (Ms)

Director, Corporate Communications Division

Ministry of Health

Correction note: This letter has been edited for accuracy.