Booster meaning: what a booster shot is and when your child gets one

Booster is the word for an extra dose of a vaccine your child has already had, given months or years after the first doses to keep protection up. HealthHub says some immunisations need these additional doses later in life to maintain immunity, for example against diphtheria and tetanus. That is the booster meaning on a vaccination record: a planned top-up of an earlier vaccine.

Why some vaccines need a booster

A KKH article on HealthHub explains that some vaccines give immunity for life, while others need repeated booster shots to keep it. SingHealth Polyclinics says the same in plainer words: some vaccines have to be given again later in life to maintain your child's immunity, and this top-up dose is called a booster.

Schedule tables use short codes for this. MOH's table key writes doses as D1, D2 and D3 and boosters as B1 and B2. So 5-in-1 (B1) at 18 months means the first booster of the 5-in-1 vaccine.

The three boosters on the NCIS

The NCIS has three booster doses in childhood:

• 12 months: the pneumococcal booster. HealthHub says infants get PCV13 at 4 and 6 months, with a booster at 12 months.
• 18 months: the first DTaP booster, given as the 5-in-1, which also carries polio and Hib. MOH's table lists 5-in-1 (B1) at 18 months.
• 10 to 11 years: the second DTaP booster, given as Tdap, HealthHub's DTaP leaflet says.

The 10 to 11 year booster usually happens at school. NUP says booster vaccinations from 10 years old are managed by the Health Promotion Board's School Health Services, and its polyclinics vaccinate children only until before age seven.

Cost and side effects of booster doses

A booster is part of the NCIS, so the same subsidy rules apply as for the first doses. MOH says eligible Singapore Citizen children get full subsidies for nationally recommended vaccinations at CHAS GP clinics, and eligible citizen and PR children may get up to full subsidies at polyclinics. MOH says no application is needed.

Expect the same kind of reaction as the earlier doses. SingHealth Polyclinics says some babies get a mild fever, mild swelling or soreness where the jab went in. HealthHub's vaccine leaflets say to see a doctor if side effects do not get better or become worse.

If your child is late for a booster

A late booster can still be given. KKH, writing for SingHealth, says a child who has had some shots and then fallen behind can catch up without starting the whole schedule again. Book the next slot and bring the Health Booklet so the nurse can see what is done.

For the pneumococcal vaccine, HealthHub says children who fall behind should get catch-up doses through to 59 months of age. Your doctor will work out which doses are still due. Our guide to baby vaccinations in Singapore covers the whole schedule.

Frequently asked questions

What is a booster shot?

It is another name for a booster dose. SingHealth Polyclinics calls it the top-up dose that keeps your child's immunity up after the first course. Booster shot, booster dose and booster vaccine all mean the same thing.

What does B1 mean on the vaccination schedule?

Booster 1. MOH's schedule key reads D1, D2 and D3 for dose 1, 2 and 3, and B1 and B2 for booster 1 and 2. So PCV (B1) at 12 months is the first pneumococcal booster.

How many boosters does my child need?

Three on the current NCIS: PCV at 12 months, the 5-in-1 at 18 months and Tdap at 10 to 11 years. Your doctor can confirm which are due for your child.

Does a booster mean the first doses did not work?

No. A KKH article on HealthHub says some vaccines give lifelong immunity while others need repeated booster shots to maintain it. The booster is planned into the schedule from the start.

Related terms

• DTaP (Diphtheria, Tetanus and acellular Pertussis): The diphtheria, tetanus and whooping cough vaccine, given inside the 6-in-1 and 5-in-1 jabs from 2 months.
• PCV (Pneumococcal Conjugate Vaccine): The pneumococcal vaccine Singapore babies get at 4 and 6 months, with a booster at 12 months.
• NCIS (National Childhood Immunisation Schedule): Singapore's official list of recommended childhood vaccines and the age each dose is due, from birth to 17 years.
• Health Booklet: The Child Health Booklet every Singapore baby gets at delivery. It records growth, milestones and every vaccination.
• MMR (Measles, Mumps and Rubella): The measles, mumps and rubella vaccine. Singapore children get it at 12 months and again at 15 months, as MMRV.
• Polyclinic: A public primary care clinic with subsidised fees, where Singapore families can take children for jabs and checks.

See every term in the glossary