Everything you need to know about Covid-19 booster vaccines
AstraZeneca head says UK needs more time to decide whether to provide top-up jabs for all adults
The chief executive of AstraZeneca has said that the UK is still “a few weeks away” from being able to make a decision on whether or not to provide booster vaccines for adults.
Over the past few days, pressure has been increasing on the government’s scientific advisers to move ahead with the proposed top-up programme. This follows the experts’ decision on 1 September to give the green light for patients with weakened immune systems to be offered a third jab.
Writing for The Telegraph on Tuesday, Pascal Soriot of AstraZeneca and Sir Mene Pangalos, the executive vice president of BioPharmaceuticals R&D, said the UK needed more time to research the effectiveness of two doses.
“Moving too quickly to boost across the entire adult population will deprive us of these insights, leaving this important decision to rest on limited data,” they warned. “A third dose for all may be needed, but it may not. Mobilising the NHS for a boosting program that is not needed would potentially add unnecessary burden on the NHS over the long winter months.”
Their intervention was published a day after vaccines minister Nadhim Zahawi told the House of Commons that the NHS is “ready to go” with the booster programme. Zahawi told MPs “that third jabs were the key to transitioning from pandemic to endemic status in Britain”.
On Wednesday (8 September), health secretary Sajid Javid declared that the Joint Committee on Vaccination and Immunisation (JCVI)’s work on Covid booster vaccines was “almost done” and that a rollout was set to be recommended in the “next few days”, The Mirror reported.
Approved roll-out for vulnerable
On 1 September, it was announced that half a million people aged 12 and above who have not “generated a full response to their initial course of Covid vaccine” due to a severely weakened immune system will definitely be offered a third jab, The Guardian reported.
Health officials have said that these “shots are not boosters… but instead form part of the primary vaccination schedule” for immunocompromised patients.
Professor Anthony Harnden, deputy chairman of the JCVI, said at the time that it was “highly likely” the UK would roll out a wider vaccine booster programme, adding that the plan would “be decided over the next few weeks”.
Appearing on BBC Radio 4’s Today programme, he continued: “we are talking about boosting many, many millions of people and therefore we want to get the strategy right on this”, adding: “it’s just a question of how we frame it”.
Why might boosters be needed?
Scientists say the need for booster vaccines is largely down to waning effectiveness as no vaccine is 100% protective and almost all decline in effectiveness over time. Immunity among fully vaccinated people appears to ebb over time, with data from Israel, where 78% of people aged 12 and over are fully vaccinated, suggesting that there has been a large increase in infection rates in recent months.
The Middle Eastern nation is now “logging one of the world’s highest infection rates”, with nearly 650 new cases daily per million people, more than half of whom are fully vaccinated, according to Science.
Data from the Zoe Covid Study app has also suggested that vaccine protection against infection falls over time.
The study found that protection from two shots of the Pfizer-BioNTech jab “decreased from 88% at one month to 74% at five to six months”, while protection against infection after two Oxford-AstraZeneca jabs “fell from 77% to 67% at four to five months”, The Guardian said.
Professor Tim Spector, the lead scientist on the study, told Sky News: “In my opinion, a reasonable worst-case scenario could see protection below 50% for the elderly and healthcare workers by winter.”
Which vaccines will be used?
Harnden has said the JCVI is awaiting the results of the COV-Boost study, which is exploring the use of seven different types of Covid jab, and aims to discover which vaccines against Covid-19 are most effective as booster vaccinations. This may vary depending on which jab people had first.
The study could “shed light on whether a booster jab will have more effect if it involves mix-and-matching vaccines”, said the London Evening Standard, with patients possibly receiving a different vaccine than their initial jab.
The vaccines currently being trialled are the Oxford-AstraZeneca, Pfizer-BioNTech, Moderna, Novavax, and Johnson & Johnson jabs, as well as French vaccine candidate Valneva and the first-generation vaccine candidate from Curevac.
The COV-Boost study also said it will be trialling the Novavax, Valneva and Pfizer-BioNTech vaccines as a half dose, as if it is found to be effective, “it could allow for double the number of vaccinations to be given using the same vaccine supply”.
How effective are Covid-19 boosters?
The World Health Organization (WHO) has argued that a rush to roll out boosters is unnecessary until we have further data on their effectiveness and the best timings to administer them.
“We don’t understand who is going to need a booster, how long after their last dose, or which vaccine combination works best,” Bruce Aylward, a senior adviser at WHO, told Science, adding: “You need to understand all that before you decide how boosters should be used.”
But there have been some promising results from Israel, who rolled out booster shots for fully-vaccinated over-60s on 30 July “in a bid to curb an outbreak of the Delta variant”, reported Reuters.
According to a study released by Israel’s health ministry, a third dose of the Pfizer vaccine significantly improved protection from infection and serious illness compared to those who had only received two shots.
Throughout August the booster program was gradually rolled out to more of the population, and third shots have been available to everyone over the age of 30 since 31 August.
Israelis are currently “required to wait five months after their second dose” before they can receive a booster, CNBC said.
Who will be the first to get one?
The JCVI has previously said that the over-70s and extremely clinically vulnerable people should be included if a booster vaccination programme goes ahead, reported the BBC.
And speaking to BBC Breakfast in early September, Harnden said that as older people received vaccines a long time ago, their immunity is more likely to have “waned”. Ultimately, however, it is still uncertain who will be eligible to receive a booster shot and when the rollout might begin.