This month has seen three major vaccine breakthroughs, giving hope that an end to the pandemic is in sight. 

The latest of these – the Oxford University and AstraZeneca jab – was bolstered this week by prime minister Boris Johnson indicating the “vast majority” of people most in need of protection would be able to receive vaccination by Easter.

With such positive developments, you might be forgiven for wondering whether the government needs to plough ahead with its estimated £40bn plan for mass coronavirus testing.

The answer, it turns out, is a big yes. We spoke to the experts to explain why. 

It will buy us time

The queue to get hold of a Covid-19 vaccine could be a long one. Guidance published on the government’s website revealed care home residents and workers would be prioritised, as well as older people, healthcare staff and those in high-risk categories. Black, Asian and minority ethnic (BAME) groups in areas of higher socio-economic deprivation could also be some of the first to get the jab.

But getting people vaccinated will be a major logistical undertaking and health secretary Matt Hancock’s increasing confidence that life will be closer to normal by spring could be premature.

“It’s going to take time – months at very least. And that’s assuming everything goes well,” said Professor Rowland Kao, an infectious diseases expert at the University of Edinburgh. “So we just need to temper our expectations in terms of how rapidly things go.

“That’s not a reason to think all of this isn’t fantastically good news. It just means that when the vaccine is being rolled out, we need to remain careful initially as to what that vaccine is actually doing.”

This is where mass testing comes into the equation, according to Dr Joshua Moon, a research fellow at the University of Sussex. “Eradication will require an understanding of where the virus is most prevalent and where to target vaccine resources.

“The spread needs to be monitored and measured geographically through testing to ensure vaccine resources are being targeted to where they are needed most.”

Widespread testing is needed for experts to understand coronavirus better in order to tackle it. “The reason we know about co-infection [what happens when people are infected with more than one type of virus at once] is that some people have been randomly screened when they’ve got on a flight,” said Professor Sally Cutler, a medical microbiology lecturer at the University of East London.

“We’re learning all this information because of the continual screening of the population in order to look at viral circulation, so we really must keep doing that at this point in time so that we can build up that database. 

“Testing should be permanent on the list of things we need to carry on doing, so we can generate the data to understand the efficacy of the vaccines and the virus itself.”

Mass testing will also help us tackle – and prevent – future outbreaks of other deadly viruses. “This was not the first global pandemic and, with climate shifts affecting virus and vector geography, it won’t be the last,” said Moon.

“Countries will need to prioritise the building of health systems capable of caring for populations in the event of another novel pathogen. This includes an ability to test for pathogens and support case isolation in the event of another global pandemic.”

There is a lot we don’t yet know about the vaccines

The government has said it is ready to start vaccinating in December, provided at least one vaccine is approved by regulators. The problem is that hasn’t happened yet. 

For one thing, none of the data from the experimental vaccines have been published in peer-reviewed scientific journals. “It’s a shame and that is not the best way to go about good science,” said Dr Angela Raffle, a social and community medicine lecturer at the University of Bristol.

“The news about vaccines is all very promising,” said Cutler. “But I’ve got a lot of questions over efficacy and safety that I haven’t seen any data for yet.

“If you actually look at the data from the various trials you realise the numbers [of volunteers] are so small, as well as the fact that you don’t know how many cases have occurred through community transmission.

“Another thing I’m really worried about is that the people who generally volunteer for vaccines will have been relatively healthy in all other aspects. What about the people in the general population that may have co-morbidities: the diabetics, the people with cancer and immunosuppressive therapies?

“The ones who are going to be top on the priority list are vulnerable, and I’m really nervous about what is going to happen with these groups. How are they going to respond to the vaccine? We just don’t know because we don’t have the data on that.”

Kao agreed there is a considerable knowledge gap regarding the vaccines. “One of the most important things to note at the moment is that there is still a lot of things we don’t know about any of the candidate vaccines.”

Key to controlling the spread of Covid-19 is breaking transmission, and it is not yet known what role the vaccines will play in that. 

“It’s really good news that people are being protected from getting symptoms or testing positive, but it doesn’t tell you whether or not these individuals are also prevented from being infectious and giving the virus to others,” he continued. “It doesn’t guarantee that transmission might go on for quite a long time even after a vaccine is deployed.”

There is also a question mark over the form and length of immunity that is generated from Covid-19, and what antibodies are needed to mount an effective response. “We don’t know anything about the duration of the vaccines’ protection,” said Cutler. 

“Some people who have been naturally infected with the virus are actually coming down with reinfections, so if the vaccine is going to be the same then that is quite concerning.”

There is no silver bullet to ending the pandemic

Cautious optimism should rule, instead of placing all our hopes in the vaccine basket. “You have to be careful not overhype any individual thing as being the thing that’s going to solve everything,” said Kao.

“The point is that this isn’t a ‘one silver bullet’ kind of situation – it’s about the different tools we have at our disposal that will help us, which hopefully means we will get things back to something close to normal sooner, rather than later.” 

The problem with mass testing in the UK is that – in its current form – it is extremely flawed. “Mass testing will help give that broad overall population-level perspective. The problem is the current testing programme has not been sufficient. It needs to be faster and it needs to be able to convince people to comply with things like self-isolation.”

As Cutler puts it, the model of an infectious disease such as Covid-19 is like an iceberg. “You only get the peak sticking up above the water, and that’s just symptomatic individuals. The problem with earlier testing was that you could only get a test if you were symptomatic.

“The bulk of people under the surface feel fine and didn’t get tested, so a lot of people out there in the community carried on life as normal, potentially spreading infection with them. The way testing is being rolled out now and broadened to be more accessible is finally positive.”

It’s also very expensive. “If you look in the BMJ [British Medical Journal], you will see the level of disquiet from highly-experienced health professionals at the way the government has gone about its decision-making,” said Raffle.

“Ministers can wake up one morning and decide they’re going to spend £100bn on a mass testing programme, without even asking their very own national screening committee.

“For mass testing to be a worthwhile use of resources, we need to evaluate it really carefully. You need to be ethical. You need to respect people’s autonomy; treat them like adults. No coercion, no persuasion.”

There’s also the concern that widespread testing could give people a false sense of security, as rapid Covid tests don’t detect 100% of cases and a person can risk being infected after taking one. 

“When you do mass testing, the impact of telling people who are negative could actually wipe out any potential benefit, because all those negative people might go: ‘Oh I don’t need to worry so much,’” said Raffle.

“Unless we really impress on everybody who is negative that negative is not really a guarantee, then mass testing could actually be counterproductive.”

Although that glimmer of hope on the horizon isn’t entirely misplaced, Cutler admits our race to find the Covid-19 vaccine could potentially be a “double-edged sword”. “The world is crying out for vaccines but the public will absolutely crucify anyone if something goes wrong.

“The danger is that bad news for one vaccine would be really bad news for all vaccination campaigns, because a lot of the general public will see something bad happening in one vaccine and think that applies to all vaccines.”

She uses the resurgence of measles in the UK is an example of the “lasting legacy” of public mistrust towards vaccinations. “We’re still suffering the consequences of that now.”