Flu vaccination is one of the best ways to help protect against catching and spreading flu. Protection starts around two weeks after having the vaccine.
Flu viruses are constantly changing. Each year flu vaccines are changed to match the flu viruses that are likely to be circulating.
Like all medicines, no vaccine is completely effective. You might still get flu, but your symptoms are likely to be milder. Flu vaccines do not protect against colds, other respiratory viruses, or other winter illnesses.
Rydym yn croesawu gohebiaeth a galwadau ffôn yn y Gymraeg neu'r Saesneg. Atebir gohebiaeth Gymraeg yn y Gymraeg, ac ni fydd hyn yn arwain at oedi. Mae’r dudalen hon ar gael yn Gymraeg drwy bwyso’r botwm ar y dde ar frig y dudalen.
We welcome correspondence and telephone calls in Welsh or English. Welsh language correspondence will be replied to in Welsh, and this will not lead to a delay. This page is available in Welsh by clicking ‘Cymraeg’ at the top right of this page.