A fourth Covid jab is not yet needed, say UK experts, because booster doses continue to provide high protection against severe disease from the Omicron variant among older adults.
UK Health Security Agency data shows three months after boosting, protection against hospitalisation remains at about 90% for people aged 65 and over.
Protection against mild symptomatic infection is more short-lived.
That drops to about 30% by about three months.
Figures also show why it is important to get a booster dose if you have only had two doses so far.
With just two vaccine doses, protection against severe disease drops to about 70% after three months and to 50% after six months.
The Joint Committee on Vaccination and Immunisation (JCVI), which advises on vaccine policy, says the priority therefore remains to get first, second and third doses to those who have not already had them.
This is despite some countries such as Israel starting to give fourth Covid shots to manage the highly infectious Omicron variant that is causing rising numbers of infections around the globe.
Over 35 million boosters and third doses have now been administered in the United Kingdom.
“The current data show the booster dose continues to provide high levels of protection against severe disease, even for the most vulnerable older age groups,” said Prof Wei Shen Lim, the JCVI’s chairman of Covid-19 immunisation.
This is very encouraging and emphasises the importance of a booster shot.
“With Omicron spreading widely, I encourage everyone to come forward for their booster dose, or if unvaccinated, for their first two doses, to increase their protection against serious illness.”
‘Not the right time’
Professor Anthony Harnden, deputy chairman of the JCVI, stated that if data showed a decline in immunity against severe disease in the elderly, immediate action would be required.
“But for the time being, all signs point to a positive outcome,” he told BBC Radio 4’s Today programme. “What is not long-term sustainable is a vaccine programme that delivers a vaccine every three months.”
He stressed the importance of getting the timing of any potential fourth dose of a vaccine for vulnerable people just right.
“Which could be later this year… we just don’t think it’s the right time right now,” he explained.
Meanwhile, extremely vulnerable patients with compromised immune systems are still advised to receive four shots in total, rather than the standard three, to be fully vaccinated.
Despite the fact that vaccines are effective, the high number of infections means that some people will still become ill and require hospitalisation.
A psychology lecturer has told the BBC he believes varying coronavirus rules across the UK are causing people to feel “fatigue” and “uncertainty”.
Dr Simon Williams from Swansea University said: “When you’ve got different rules in different countries, but effectively we are still sharing the UK, it really hampers people’s understanding and it also undermines rules on both sides.”
Health Secretary Sajid Javid says he was concerned by rising Covid hospital admissions, particularly in older age groups in this Omicron wave.
“We are still seeing rising hospitalisations, particularly with the case rate rising with older age groups – that is of concern,” he said.
“And I think we have to be honest when we look at the NHS and say it will be a rocky few weeks ahead.”
Alongside rising hospitalisations, Covid-related staff absences in England have risen sharply, with the number of workers off sick for Covid reasons having trebled from the beginning of December, the latest figures show.
About 4% of hospital staff in England – nearly 36,000 – were off for Covid reasons each day during the week ending 2 January.
When other sickness absence is added it brings the total off to 9% – nearly double what would normally be seen at this time of year.