A Covid vaccine that prevents transmission is missing from our arsenal

Two years since the new coronavirus hit the world there is a missing link in the public health intervention

A member of the public places a Covid test sample in a container at a Covid-19 Test Site at Edinburgh Airport , Scotland, where people have been asked to reduce their social contact as much as possiblShow more

If the Covid-19 pandemic is ever going to be defeated, the world needs to unite behind funding a vaccine that will ultimately kill off the virus, leading scientists told The National.

Two years on from when the disease first appeared in Wuhan, China, the international community is still trapped in a cycle of keeping ahead of the coronavirus, adjusting vaccines in response to mutations.

The Omicron variant sweeping across the globe is one of many new strains that could potentially prove deadlier and more transmissible unless a next-generation vaccine is developed.

A dose that makes Covid non-transmissible – like the polio or smallpox vaccines – is still uncertain, with scientists fearing that the virus might never be countered.

“We need a vaccine everywhere and for everybody, because this is a public health intervention and until that happens we are stuck in a cycle,” said Prof David Heymann, formerly of the World Health Organisation.

“Once we get a second-generation vaccine that prevents transmission, which I sincerely hope happens but there are no guarantees, then it's an entirely different story.”

Funding is key

To get to that position a considerable amount of funding will be required, according to Charlie Weller, head of infectious disease prevention at the Wellcome Trust medical foundation.

“International funding is not keeping pace with global research needs,” Ms Weller said. “The WHO’s Access to Covid-19 Tools Acceleration needs an investment of $16.8 billion this year to get lifesaving tests, treatments and vaccines from the laboratory to the front line in the countries that need them most.”

Ultimately, it will benefit the global economy to find a lasting solution to Covid, Dr Ilan Kelman said.

“We're looking at $20 to $30 trillion per year of damage to our world from the pandemic, so putting in a couple of $100 billion into different types of treatments and vaccines is nothing,” said Dr Kelman, professor of disasters and health at University College London. “It’s a false argument to suggest there’s ‘a trade-off’ as you’re not just saving trillions of dollars in damage every year but millions of lives. The knowledge that we have gained from this rapid development of vaccines should absolutely be put into preventing the next pandemic.”

Richer countries had to now move on their funding pledges to avoid further catastrophe because “we are far beyond the time for warm words”, said Sir Jeremy Farrar, a former member of the UK’s Scientific Advisory Group for Emergencies,

“We must invest far more now in next-generation therapeutics and vaccines, ones that not only stop sickness and death, but also prevent transmission and work against potential new variants,” the Wellcome Trust’s director told the BBC.

In a paper passed to The National, his colleague Ms Weller said that “private and philanthropic collaboration on a global scale” was required alongside financial investment on “a never-before-seen level” to develop vaccines.

Next-generation vaccines

The coming year will be key in achieving what “we have so far failed to do” Mr Farrar said, if we are to get ahead of the pandemic and “break this vicious reactive cycle”.

With current inoculations being adjusted to tackle variants such as Omicron, scientists have to rapidly start on third-generation vaccines to address Covid in the long term.

“Within three to five years, scientists will be looking at developing vaccines which cover and protect against multiple variants of Sars CoV-2 and even against multiple coronaviruses,” Ms Weller said.

But there are still many unanswered questions, such as for how long will vaccines provide protection?

“For one year, two years or longer? By knowing this, we may be able to make current vaccine supplies go further,” she said.

Her caveats on a long-term solution are endorsed by Prof Heymann. “It’s going to be a big challenge,” he told The National. “It's questionable whether we will even be able to develop a next-generation vaccine that can prevent transmission. The virus rapidly evolves and mutates, doing what we call ‘drift’, which is what the influenza virus does, in that it changes in such a way as it escapes the immune protection.”

North versus South

There is another little-discussed issue that is playing a significant role in the continuing pandemic.

On the one hand the World Health Organisation and others are calling on richer countries to supply millions more vaccines to the developing world, but these nations do not have the finance, infrastructure or inclination to vaccinate.

“Many developing countries don't yet have the capacity to do that,” said Prof Heymann, who played a significant role in containing the 1976 Ebola outbreak in Zaire, Africa.

“We've seen vaccines wasted in some countries because it's not usual in the southern hemisphere countries to give adult vaccinations like we do in western countries for influenza. They’ve never done this before.

“Also, southern Africa countries prioritise malaria as they see more deaths from that than they do from Covid, so it's a really complicated issue.”

Despite the African continent experiencing a major surge in Omicron cases, there is also a risk that developing countries will question why they should continue Covid boosters because “they think ‘we are doing this is for the northern hemisphere, not for our own countries because we don't need it’”, Prof Heymann said.

Dr Kelman said that asking for continuous inoculation from the developing world could prove too onerous.

“I think that’s absolutely right in regards to the southern hemisphere,” he said. “The diseases that have been eradicated there, such as smallpox or polio, did not require a new shot every six or 12 months. These countries simply don’t have the capacity or the infrastructure for a boost with the huge cost, time and resources.”

Universal vaccine

To be able to make it a global drug, scientists engineering the third generation will need a vaccine that is simple to store without significant refrigeration, easy to manufacture and can protect long term against new variants.

“It can act as a universal coronavirus vaccine,” Ms Weller said. “It may be possible to create a vaccine that protects against all Sars CoV-2 variants and other coronaviruses.”

Because current vaccinations do not provide long-lasting immunity, the universal vaccine is necessary to prevent reinfection, Prof Heymann said. “You'll have to modify it in such a way that it's not similar to the virus. Furthermore, decreasing transmission decreases the risk of mutations occurring allowing the virus to replicate in new people. That has to stop.”

Despite the huge scientific progress made during the two-year pandemic, Mr Farrar said he found it “staggering and deeply frustrating” that governments had failed to unite against the virus. “They are still not anticipating events or working together anywhere near the scale that is required,” he said.

Omicron’s universal spread in early 2022 may well prompt the world to act with a more unified response.