How many people need to be vaccinated to get back to normal?
Herd immunity percentage is not a ‘magic threshold’
The UK has taken another tentative step out of lockdown, with the return of indoor socialising at home and in pubs and restaurants.
The blanket travel ban has been lifted, and theatres, sports stadiums and cinemas can reopen, in what has been billed as the penultimate stage before all restrictions are removed on 21 June.
However, the prime minister has warned that the race between the virus and the country’s vaccination rollout could become “a great deal tighter” with the emergence of the Indian Covid-19 variant.
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.
Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
How many vaccines so far?
The UK administered 56.7 million jabs up to 16 May, according to the gov.uk website. First doses have been given to 36.6 million people, while 20.1 million have also had a second shot.
Oxford University researchers calculate that this amounts to nearly 30% of people in the country having full protection, while nearly 54% have partial protection, the highest national proportion in the world apart from Israel.
How many people need the jab?
Sign up for Today's Best Articles in your inbox
A free daily email with the biggest news stories of the day – and the best features from TheWeek.com
Johnson’s roadmap for ending the UK’s third lockdown is contingent on the vaccine rollout continuing at pace. Ahead of each step in the lockdown-easing plan, ministers have been weighing up the vaccine rate and its effectiveness in reducing hospitalisations and deaths, against the risks of infection rates and new variants.
The government has said all adults, which make up about 80% of the population, will be offered a vaccination by the end of July. However, not all adults are able or willing to have the shot.
“To go back to a pre-pandemic lifestyle, we would need at least 70% of the population to be immune to keep the rate of infection down (‘achieve herd immunity’) without restrictions on activities,” say Gypsyamber D’Souza and David Dowdy, epidemiologists at Johns Hopkins Bloomberg School of Public Health.
But they say that the herd immunity percentage is not a “magic threshold”, as both viral evolution and changes in human interaction can affect the number.
With an “amazingly successful” vaccination drive, and cases, hospitalisations and deaths down, there is a “window of opportunity to eliminate the virus in the UK, or at least to bring it to near extinction, and to concentrate on controlling isolated outbreaks”, says Adam Kleczkowski, professor of mathematics and statistics at the University of Strathclyde, writing for The Conversation.
However, he notes that the herd immunity threshold for new variants is “probably higher” than 70% and that, as vaccinations are not 100% effective, a higher proportion of the country will need to be treated. If unvaccinated people are concentrated in the same area, there is also a risk of pockets becoming “a breeding ground for super-spreading events”, says Kleczkowski.
“Globally, extremely uneven vaccination rates pose another hurdle to herd immunity,” writes Joshua Cohen in Forbes. As each successive wave proves, “the virus is highly transmissible and frequently generates new variants of concern”, says Cohen, and this has “important implications for public health policy in countries that are presently ahead in the vaccination race”.
Create an account with the same email registered to your subscription to unlock access.
-
Long Covid: study shows damage to brain's 'control centre'
The Explainer Research could help scientists understand long-term effects of Covid-19 as well as conditions such as MS and dementia
By The Week UK Published
-
Israel, UN agree to Gaza pauses for polio vaccinations
Speed Read Gaza's first case of polio in 25 years was confirmed last week in a 10-month-old boy who is now partially paralyzed
By Rafi Schwartz, The Week US Published
-
FDA OKs new Covid vaccine, available soon
Speed read The CDC recommends the new booster to combat the widely-circulating KP.2 strain
By Peter Weber, The Week US Published
-
Mpox: how dangerous is new health emergency?
Today's Big Question Spread of potentially deadly sub-variant more like early days of HIV than Covid, say scientists
By The Week UK Published
-
What is POTS and why is it more common now?
The explainer The condition affecting young women
By Devika Rao, The Week US Published
-
Brexit, Matt Hancock and black swans: five takeaways from Covid inquiry report
The Explainer UK was 'unprepared' for pandemic and government 'failed' citizens with flawed response, says damning report
By Harriet Marsden, The Week UK Published
-
Should masks be here to stay?
Talking Points New York Governor Kathy Hochul proposed a mask ban. Here's why she wants one — and why it may not make sense.
By Anya Jaremko-Greenwold, The Week US Published
-
Covid might be to blame for an uptick in rare cancers
The explainer The virus may be making us more susceptible to certain cancers
By Devika Rao, The Week US Published