Plans for a UK Covid vaccine booster programme this autumn have caused controversy: proponents say it will help save lives and maintain freedoms, but others argue it is more important to send jabs abroad to countries where many have yet to receive even their first dose. We take a look at the current UK plans, and the evidence behind them.
What does the current UK Covid booster programme look like?
That seems to depend who you ask. The Joint Committee on Vaccination and Immunisation (JCVI), which advises the government on vaccine policy, has not yet given its final advice on the booster programme. But on Tuesday, the health secretary, Sajid Javid, suggested over-50s were likely to be offered a booster at the same time as a flu jab, with the rollout expected from early September.
That chimes with interim guidance from the JCVI in June which said if a booster programme were to go ahead, jabs should be given to at-risk adults, over-50s and adults living with people who are immunosuppressed.
But on Wednesday, Prof Adam Finn, a member of the JCVI, suggested the programme may be more targeted as â€œwe clearly donâ€™t want to be giving vaccines to people that donâ€™t need themâ€.
Will the boosters be different from the jabs administered so far?
The Guardian understands the booster doses will not be specifically tweaked to tackle the Delta variant which has become the UKâ€™s dominant variant. Officials pointed to data from Public Health England suggesting the Pfizer/BioNTech vaccine is 96% effective and the Oxford-AstraZeneca vaccine is 92% effective against hospitalisation after two doses.
Do we need boosters?
This week, the World Health Organization (WHO) said it is not clear if waning antibodies, noted in some studies, means a decline in vaccine effectiveness. Indeed, the bodyâ€™s immune response involves more than antibodies, with components such as T-cells also important, while it remains unclear exactly what levels of these are needed for protection.
The WHO adds that even if defence against infection declines, protection against severe disease is likely to remain â€“ and booster shots should be prioritised to protect against the latter.
Danny Altmann, professor of immunology at Imperial College London, said the question is tricky as the data is mixed. For most people, data from immune monitoring suggests both antibodies and T-cells are high after two doses, with it taking 200 or more days for levels to halve. â€œThese datasets also suggest most are on a plateau and may not get a lot extra from a rapid boost,â€ he told the Guardian.
However, Altmann noted the Delta variant complicates matters. As data from Israel and the UK has shown, while the chance is reduced, fully vaccinated people can still get infected with the coronavirus and in some cases hospitalised. â€œYou get Delta breakthrough cases especially in over-60s and [a third dose] mitigates this. The same will apply to other vulnerable or immune suppressed groups,â€ said Altmann. â€œThe ideal would be to have targeted boosting rooted in data and immune monitoring.â€
Dr Rupert Beale, the head of the cell biology of infection laboratory at the Francis Crick Institute in London, said â€œthe argument for third doses in some clinically extremely vulnerable groups is overwhelmingâ€ but the case for boosters across a wider section of the population isless clear. â€œThey will definitely be beneficial, but there is a point to be made about vaccine equity,â€ he said.
What are other countries doing?
While the European Medicines Agency said last month there was not enough evidence to recommend boosters, some countries have gone ahead anyway. France and Germany are looking at rolling out third doses for certain groups from September although whether they will do so before the UK remains unclear.
According to Reuters, Germanyâ€™s health ministers have decided all booster shots should be mRNA vaccines, meaning either Pfizer/BioNTech or Moderna, regardless of which type of Covid vaccine individuals had received previously.
A mix and match approach is being considered by the JCVI, as a growing body of research suggests the approach could generate a stronger immune response as well as greater flexibility.
Israel has begun giving boosters to over-60s, with the president, Isaac Herzog, already receiving his third dose.
Are there enough vaccines worldwide for richer countries to have booster programmes without poorer countries missing out?
The WHO seems to think not, calling for a halt to booster programmes until at least the end of September and saying: â€œIn the context of ongoing global vaccine supply constraints, administration of booster doses will exacerbate inequities by driving up demand and consuming scarce supply while priority populations in some countries, or subnational settings, have not yet received a primary vaccination series.â€ According to Our World in Data, only 1.2% of people in low-income countries have received at least one dose of a Covid jab, compared with 69.5% in the UK.