At present, to be fully vaccinated against Covid-19 in the UK you need to have had two jabs of AstraZeneca, Moderna or Pfizer. But it looks like two doses could soon be just the beginning, with health secretary Sajid Javid announcing that the NHS will start to give out third jabs.
Javid confirmed the move on Thursday, saying that the scheme would begin “some time in September”, with the current details to come after final advice from the Joint Committee on Vaccination and Immunisation (JCVI).
The UK will be one of several countries to give out vaccine “boosters”, with France, Israel and Germany also doing so. The move goes against official advice from the World Health Organization, who say that the shots would be better delivered to developing countries where fewer people have had two vaccines.
So what will the booster vaccine scheme look like in the UK? We answer your questions below…
Who is eligible for a booster vaccine?
Originally, the JCVI had advised a programme of third doses for all over-50s in the autumn. However, sources close to the committee this week told The Telegraph that there is not enough evidence for doing this, and a different approach will be taken instead.
Instead, a “far more restricted” group will be offered boosters, which will be limited to just the “most vulnerable”. At this stage the criteria for deciding who that applies to is still unknown, but it could include everyone over a certain age, or only those with pre-existing conditions.
A clue about who might be eligible comes from Professor Adam Finn, a member of the JCVI, who this week told the BBC that those who most need a third dose are “people who we know are very unlikely to be well protected by those first two doses”. This would likely include people with weak or suppressed immune systems.
Dr Cheryl Walter, a virus expert and lecturer at the University of Hull, explains that boosters may also be offered to groups most at risk of getting seriously ill or dying from Covid, who were also prioritised in the first vaccine roll-out – such as older people or those with pre-existing conditions that put them at risk. “Most of the rationale is because they’re in the high-risk groups, not because they’re not responding to the vaccine”, she says.
When will booster jabs be available?
According to Javid, the scheme will begin in September. However, how people will be prioritised is not yet known. It could be that the oldest people are invited first, or those with certain medical conditions.
How do boosters work?
Although the Covid-19 vaccines are very effective in the first months after getting them, that efficacy may decline relatively quickly when compared to other inoculations. For example, immunity after getting the HPV jab is thought to last for at least 10 years, but that could be more like one year for the Covid vaccines, says Walter.
“These vaccines are a marvel, but because of the nature of Covid-19 that does tend to tail off”, says Walter, explaining that over time our immune systems stop making as many antibodies. Once your antibodies fall below a certain level, she says, then you are no longer considered immune to infection.
“About six months to a year [after getting your second vaccine] that antibody level starts to drop”, she says. “But when it drops below the threshold [of immunity] is specific to each individual.”
Walter says that a third vaccine works as a “reminder” to your body that it needs to keep making antibodies against Covid-19, which will give you another boost of immunity.
Is the third jab the same as the first two? Will I get a mix-and-match vaccine?
Initially, the vaccines that will be used in the booster roll-out are the same ones that were used during the initial vaccination campaign – AstraZeneca, Pfizer and Moderna. However, the JCVI is discussing whether to take a mix-and-match approach, so that the third jab people receive is manufactured by a different company than the first two. There is evidence to suggest that mixing vaccine types like this can provide stronger immunity against Covid-19.
Will I have side effects from the booster jab?
The side effects of boosters are not as well studied as what you could expect from the first two vaccines. However, according to health authorities in the US, side effects seem similar after a third dose, with the most common symptoms including a sore arm and tiredness, which would be mild to moderate.