What should I do if I miss a dose?

Last reviewed: 2026-06-08

Quick answer

In most cases you don't need to start over. For most multi-dose vaccines, you simply catch up on the remaining doses as soon as possible, and the doses you've already had still count. Don't restart the whole series. The exact plan depends on the vaccine and how many doses you've had, and health professionals adjust it from your vaccination record.

Missing a dose is common and usually straightforward to fix.

No need to start over

For most vaccines, missing or delaying a dose doesn't cancel the doses you've already had. The immune system remembers them, so you catch up on the remaining doses rather than repeating the whole series. Get the missed dose as soon as you can.

Effect on protection

Until you've completed all the recommended doses, protection may not be at its best, so catching up sooner is better. For multi-dose vaccines such as hepatitis B and HPV, completing the full series is what gives full, lasting protection.

Catch-up in the children's programme

If a child has missed vaccines under the Hong Kong Childhood Immunisation Programme, a Maternal and Child Health Centre or the Department of Health can arrange catch-up. Bring the child's immunisation record so staff can see which doses are outstanding.

Bring your record

For adults and children alike, bringing your vaccination record helps. Health professionals plan the remaining doses based on what you've had and when.

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