Eligible people are now being invited to come forward for their life-saving Spring booster jabs.
This announcement comes as the biggest and fastest vaccination programme in NHS history moves to the next phase.
The NHS has already given more than 3.8 million doses of the vaccine in Sussex, including more than 1 million boosters and third doses.
People aged 75 and over and those who are immunosuppressed will now be invited to arrange a spring booster through the National Booking Service or by calling 119 when it is their turn.
Calls to 119 are free from mobiles and landlines. Lines are open every day from 8am to 8pm, and 119 can provide support in 200 languages.
GP led teams will deliver the vaccinations, as well as hundreds of pharmacies and vaccination centres.
Local NHS teams will be contacting care homes in their area as they have done previously to arrange for Spring boosters for people who are eligible.
Caroline Reid, Regional Director of Commissioning and SRO for the Flu and Covid vaccination programme across the South East, said: “Very sadly, we have seen how Covid-19 can be more serious in older people and those with a weakened immune system.
“For this reason, people aged 75 years and over and those who are immunosuppressed are being offered the Spring booster.”
She added: “The NHS will contact those who are eligible to make a Spring booster appointment, so people should wait until they hear from us. Those whose clinical need is greatest will be prioritised, as has been the case throughout, starting with those who have had a bigger gap since their last dose, then working through the cohort to invite others.
“Everyone who is eligible will be offered this booster during spring and early summer, between three and six months after their most recent dose.”
The NHS has made it easier than ever for immunosuppressed people to get their boosters – they can now show they are eligible by providing either a letter from a GP team or specialist inviting them for a vaccine, a hospital or GP letter about their medication or treatment, or a prescription or medication box with their name and date on it.
It is still important for severely immunosuppressed people who have been advised to have a 3rd primary dose, for example those undergoing cancer treatment, to get this before getting a booster, for maximum protection from Covid-19.