A leading scientist has warned that the protection provided by two doses of the Pfizer and AstraZeneca coronavirus vaccines could fall below 50 per cent for the elderly by the winter months.
The test results from 1.2m users of the Zoe Covid app showed that protection from two jabs starts to wane “even within six months”, according to Professor Tim Spector, lead scientist on the app.
The latest analysis shows the Pfizer jab was 88 per cent effective at preventing coronavirus infection after the second jab. After five to six months, however, it fell to 74 per cent.
For AstraZeneca, protection from the virus dropped from 77 per cent a month after the second dose to 67 per cent four to five months down the line.
He added that the findings could explain the recent breakthrough infections in fully vaccinated people.
“In my opinion, a reasonable worst-case scenario could see protection below 50 per cent for the elderly and healthcare workers by winter,” he added. This could result in increased infections, hospitalisations and deaths.
“We urgently need to make plans for vaccine boosters, and decide if a strategy to vaccinate children is sensible,” Professor Spector said.
He added that waning protection is to be expected and is not a reason to not get vaccinated, as the jab still provides high levels of protection for the majority.