Herd immunity 'mythical' following Delta variant says Oxford vaccine scientist

Teenager Katie Moore receives a covid vaccination at the Barrhead Foundry vaccination centre near Glasgow, during a visit from First Minister Nicola Sturgeon (PA/Jeff J Mitchell)

Professor Sir Andrew Pollard, director of the Oxford Vaccine Group, told parliamentarians that the concept of immunity being built up in this way is “not a possibility” as people who have been vaccinated against Covid are still being infected.

Warning that any vaccination programme should not be built up around the idea of achieving herd immunity, Sir Andrew told a session of the All-Party Parliamentary Group (APPG) on Coronavirus: “We know very clearly with coronavirus that this current variant, the Delta variant, will still infect people who have been vaccinated and that does mean that anyone who’s still unvaccinated, at some point, will meet the virus.”

He said while vaccines might “slow the process” of transmission down, at the minute they cannot stop the spread completely.

He added: “I think we are in a situation here with this current variant where herd immunity is not a possibility because it still infects vaccinated individuals.”

Prof Sir Andrew’s comments came as it was announced that three quarters of adults across the UK have now been double vaccinated, with more than 86 million jabs handed out in total.

Health Secretary Sajid Javid said yesterday that plans are being put in place to extend the roll out of booster injections from next month, however Prof Sir Andrew said “there isn’t any reason at this moment to panic” about needing a third jab.

He explained: “The time which we would need to boost is if we saw evidence that there was an increase in hospitalisation or people dying amongst those who are vaccinated. That is not something that we’re seeing at the moment. But we have to also have an understanding scientifically about how the vaccines work and they are providing very high levels of protection against that severe end of the spectrum, but also (...)our immune system still remembers that we were vaccinated and we’ll be remembering decades from now that we have those two doses of vaccine.

“So there isn’t any reason at this moment to panic.”