Experts back booster jabs
EXPERTS have warned of waning coronavirus immunity in those who have been double jabbed.
While it is not unexpected for immunity to drop with time, experts are now debating what that means and what should be the next step in protection from the Covid-19 virus as data suggests vaccines are being weakened by the Delta variant.
The Mirror reported yesterday that experts have spoken out on vaccine efficacy and that it could drop below the acceptable level of 50 percent within months, prompting calls for booster jabs this winter.
Using data given by millions of app users, the Zoe Covid Symptoms Study has calculated how well the jabs are protecting the population.
The organisation has reported that the Pfizer vaccine is 88 percent effective a month after the second dose – although this drops to 74 percent after five or six months.
The Astrazeneca vaccine is 77 percent effective a month after the second dose, reducing to 67 percent at five months.
Professor Tim Spector, lead scientist on the study, said: “In my opinion, a reasonable worst-case scenario could see protection below 50 percent for the elderly and healthcare workers by winter.”
The findings were measured against the risk of infection from coronavirus using swab test data of participants – not hospitalisation and death.
Experts are concerned the vaccines will not protect up to half of cases come winter.
Professor Spector still urged people to get the vaccine as it still worked strongly against the fastspreading Delta variant now dominant in the UK.
The World Health Organisation says a vaccine must reach 50 percent efficacy to be approved.
Professor Spector said: “If there are high levels of infection in the UK, driven by loosened social restrictions and a highly transmissible variant, this scenario could mean increased hospitalisations and deaths.”
“Vaccines still provide high levels of protection for the majority of the population, especially against the Delta variant, so we still need as many people as possible to get fully vaccinated.”
He added: “We urgently need to make plans for vaccine boosters, and based on vaccine resources, decide if a strategy to vaccinate children is sensible if our aim is to reduce deaths and hospital admissions.
“The first sign of waning immunity may be that cases are no longer falling at speed.
“It looks like the younger ages are dropping slightly and the older ages seem to be increasing slightly and the older ages generally are the fully vaccinated groups.”
Although the Pfizer jab is initially more protective, it’s not much better than Astrazeneca over time, the data suggests. The findings match with a separate study revealed last week.
Oxford University found protection after two Pfizer doses reduced from 90 percent to 85 percent after two months, and 78 percent after three. For Astrazeneca, it came down from 67 percent to 65 percent and then 61 percent.
A decision is expected on booster imminently.