Q: Are you worried about being sucked into a situation where you are always taking the precautionary approach and giving booster vaccines?
Lim says that is an important question. But over time they expect to get better data about how long vaccine effectiveness lasts, he says.
He says it is also possible that the third dose will extend the time protection lasts.
And they do not know how natural infection might top up the immunity offered by vaccines, he says.
Van-Tam says he agrees.
Today’s advice is for this winter only, he says. He says the government will keep asking the JCVI to come back to this until the Covid situation returns to normality.
Van-Tam says the protection offered by initial vaccines is more important than the protection offered by booster vaccines.
He says the vaccine offer is an evergreen one; people can still come forward.
Lim says, as a clinician, he sees people in hospital with Covid who have not been vaccinated. It is heartbreaking, he says.
Q: Are you confident that supply of the flu and Covid vaccines won’t be affected by transport delays?
Van-Tam says there was an issue with the supply of flu vaccine from one manufacturer. But he says he has no concerns about the supply of Covid vaccines.
Q: Where will booster vaccines be delivered?
Van-Tam says this needs to start quickly. The NHS has been planning for this for months. He says they do not have ministerial approval yet. But once they do, he says he expects the NHS to be able to start “in a short number of days, not a short number of weeks”.
He says he would expect people to get booster vaccines either at mass vaccination centres or at GP surgeries.
Van-Tam says, if there is good uptake, the booster programme will make “a very substantial impact” in terms of allowing the government to “keep the lid on things” and to reduce pressure on the NHS.
Q: What do you say to scientists who say this booster campaign undermines global vaccine equity?
Van-Tam says as public health people they take a very strong view that the whole world should have access to vaccines. Until everyone is safe, nobody is safe.
But he says they also have to decide what is best for the UK.
Nine countries have said they are starting some form of booster campaign, and 18 others are considering it, he says.
So the UK is not alone, he says.
Q: The decrease in vaccine effectiveness seems really small. So why are you going ahead with this?
Lim says a drop in effectiveness from 90% to 80% may not seem like much, but it could lead to a doubling in the number of people being admitted to hospital.
If they can protect the NHS, they will save lives, he says.
Van-Tam says by January protection will have waned further. But they don’t know by how much.
The brief from ministers has been to do the most possible to prevent deaths and illness from Covid, he says.
He says if there is going to be a storm, it is better to make your tent secure in advance. It is better to be pre-emptive, and to prepare and plan for the worst eventualities.
UPDATE: Here is the quote in full.
They are now taking questions.
Q: What might happen in the future? Will AstraZeneca be used?
Lim says he cannot say. He would not want to exclude any option at this point.
Q: When will double jabs start, flu and Covid?
Van-Tam says double jabs can start now, provided the product is available.
He says the MHRA has said there is no problem with double jabs.
But it may not always be possible to co-administer both vaccines in patients.
Flu vaccines are administered quickly. But Covid jabs required a 15-minute waiting period. This means administering both at the same time might be difficult, he says.
In the future it is possible that one jab might be able to administer both vaccines, he says.
Van-Tam says today’s recommendation from the JCVI has to be approved by ministers.
But if ministers do agree, it will be “full speed ahead”, but in a “purposeful way”, he says.
Lim says today’s advice does not mean there will be a recurrent programme of booster vaccines every six months.
Further advice will be offered in the future when the country reaches a “steady state” with Covid infections, he says.
He says the advice also does not mean that everyone will need a booster dose. Younger people may not need one, he says.
And he says the booster programme does not mean that other vaccine programmes are not important. In particular, flu vaccines remain important, he says. He strongly urges people to get it.
If people have both vaccines on the same day, that will be safe, he says. Usually they would have the vaccines in different arms.
Lim says there is a preference for using mRNA vaccines – Pfizer or Moderna – for the booster vaccines.
He says an mRNA booster will give a very good response, regardless of what people had first.
He says the Pfizer vaccine is the preferred option because of its simplicity and because it is well tolerated.
But a half dose of Moderna could also be used, he says. That is because a half dose works very well, he says.
Lim says the data suggests there is a small decrease in vaccine effectiveness over time.
He says the most marked decrease in protection occurs in older people and in people with underlying health conditions.
He says the JCVI is advising that adults who are more vulnerable should be offered a booster vaccine.
These will be people who were covered by phase one of the vaccine programme – all adults over 50 and over, plus those with underlying health conditions that put them at risk, as well as health and social care workers.
He says boosters should be given no earlier than six months after the second dose.
And booster vaccines should be given in the same order as original doses, he says.
He says a longer interval to a third booster dose may be beneficial.
But they do not want to wait too long either, he says.
They are looking for a “sweet spot” – which is why they are saying not before six months after the second dose.