Scientists Call for Broadly Effective Vaccines against Potential Pandemic Viruses

Two leading scientists are calling for health agencies to invest in the development of vaccines that will be broadly effective against many different variants and strains of potential pandemic viruses.

Their call is coming as new COVID-19 variants begin to throw vaccine efficacy in question.

While many poorer countries are still waiting for vaccines to become widely available, in a number of wealthy countries, the number of COVID-19 vaccines ordered vastly exceeds what is needed.

If these rich countries’ orders are fulfilled, what will happen to the excess vaccines? Will they be wasted, traded to the highest bidder, or allocated free or at cost to those poorer countries where COVID-19 is still raging?

Lamenting many countries’ lack of access to vaccines, Head of World Health Organisation (WHO), Tedros Adhanom Ghebreyesus, has described the world as being “on the brink of a catastrophic moral failure”.

Wasting these over-ordered doses will compound this accusation many times over.

Ordering so many vaccines is not in itself immoral. It was completely reasonable that those in charge of procurement in countries such as the UK and Canada ordered a wide portfolio of vaccines. There was no way of knowing which would meet regulatory approval.

The speed of development, as well as the relatively low number of failures, has also been unexpected, producing a good number of potentially viable vaccines in a short space of time. Nonetheless, COVID-19 vaccine development cannot be considered a success until this redistribution issue is resolved.

Assessing the size of the problem

The Duke Global Health Innovation Center in the US is tracking how many vaccine doses each country has ordered. Calculating the number of surplus vaccines requires making some assumptions—for instance, that every adult will get vaccinated—so these are quite rough estimates.

The EU has ordered 1.6 billion doses for its adult population of roughly 375 million. As these vaccines require two doses to provide full protection—except for the 200 million single-shot vaccines from Johnson & Johnson—the bloc’s orders will cover just under 900 million people. If all orders are fulfilled, this creates a surplus of around 525 million full vaccinations.

Similarly, the UK has ordered 219 million full vaccinations for its 54 million adults (a surplus of 165 million), while Canada has ordered 188 million full vaccinations for its 32 million adults (an excess of 156 million).

Of course, these surpluses will change as fresh data emerges. New orders will be placed, some may be canceled, and vaccines still in development could fail during testing.

Focus is on Canada, the UK and the EU for a few reasons. While they aren’t the only nations to have over-ordered, this group of countries engages significantly with the WHO and with international development issues more generally.

Civil society organizations in the field of global justice are also active in holding these governments to account, so there’s a much greater likelihood that they will develop policies for redistribution.

Much will rest on the goodwill of governments and the nature of their contracts with vaccine makers.

It could be argued that vaccine hoarding by governments is sensible, considering the possibility that annual or periodic vaccinations may be needed. However, the expiration dates on vaccines and the likelihood that vaccines will need to be tweaked to handle new variants suggests that hoarding is irrational.

Some contracts may also allow for over-ordered batches to be deferred or canceled, but this is unlikely to make the problem of excess vaccines disappear completely.

Also, unused vaccines that have nearly expired, or those less effective in some parts of the world in the face of mutated variants of the virus, might suddenly become available for redistribution in large quantities.

Several international agencies could help with the redistribution, including the WHO, Gavi and the Coalition for Epidemic Preparedness Innovations. But perhaps the most obvious redistribution route is the COVID-19 Vaccine Global Access Facility—known as Covax.

This was set up specifically to share COVID-19 vaccines fairly around the world. It has already made progress in ordering new vaccines and planning their initial distribution, but it has yet to clarify how it would redistribute any surplus vaccines donated to it.

Covax also has no power to compel states to share their surpluses with it. The decisions of individual governments will therefore be crucial. It appears that the European Commission has decided to leave redistribution to individual countries. Norway, for instance, has committed to sending its surpluses to Covax. Canada has said it will do likewise. Other decisions are in the balance. It’s possible that vaccine surpluses may be used instead to placate near neighbors or to advance foreign-policy goals. Spain, for example, announced on January 19 2021 that it will sell 30,000 excess doses to Andorra at cost.

For countries that don’t hand their surpluses to Covax, a more positive approach would be for redistribution to be led by need. If this were the case, the next step would be to identify where vaccines should be sent.

Two targets suggest themselves: places where infection is high and places home to displaced people, such as in Yemen, Syria, South Sudan and Bangladesh, where it is difficult to socially distance and medical supplies, hand sanitiser and PPE are often lacking.

Finally, surplus vaccines requiring intense cold storage will be harder to distribute, as not all countries will have the necessary infrastructure.

One innovative idea could be to use international airports in recipient countries as “coolports”, with freezers installed and all approved vaccines administered from there. It might be easier to simply redeploy vaccines with easy storage requirements to countries where cold storage is difficult. To some extent, redistribution may end up being driven not by need or politics, but by logistics.

However, in a commentary article published in the journal Nature, Dennis Burton, Ph.D., and Eric Topol, MD, of Scripps Research call for governments to provide significant funding support for rational vaccine design based on broadly neutralising antibodies.

Such antibodies provide broad-spectrum potency against viruses, a valuable characteristic that opens the door to vaccines that could provide immunity against the many variants that might evolve from a fast-mutating virus. They could also be used as drugs to prevent and treat infections.

Burton and Topol note that the rapid development of effective vaccines against COVID-19 was possible due to certain properties of the SARS-CoV-2 virus—in particular, the spike protein on the virus’s surface.

But they warn that the virus driving the next pandemic may not provide such a ready target, which could substantially slow the process of developing a novel vaccine.

“Even SARS-CoV-2 could be becoming more problematic for vaccines because of the emergence of new variants”, they write. “We call for an alternative approach to pandemic preparedness.”

Burton and Topol point to broadly neutralizing antibodies as a promising avenue for developing vaccines and therapies that might be readily adapted to newly emerged pandemic viruses or those that rapidly evolve to evade traditional vaccines.

“Such antibodies could be used as first-line drugs to prevent or treat viruses in a given family, including new lineages or strains that have not yet emerged”, they write. “More importantly, they could be used to design vaccines against many members of a given family of viruses.”

Of particularly concern for future pandemics are viruses that are “evasion-strong,” meaning their biological characteristics make them challenging to treat with drugs or prevent with vaccines. The extreme example of this type of virus is HIV, which can stay in the body for years, hiding from the host’s immune system.

Burton and his colleagues at Scripps Research and other organizations are currently developing vaccines based on broadly neutralising antibodies in hopes of producing the world’s first truly effective HIV vaccines.

They are also seeking to employ broadly neutralizing antibodies as therapies and vaccines against influenza, another evasive virus and prime contender for future pandemics.

“Such pan-virus vaccines could be made in advance and deployed before the next emerging infection becomes a pandemic,” Burton and Topol write. “We call for an investment now in basic research leading to the stockpiling of broadly effective vaccines.”

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