Vaccines will always be our best weapon against Covid – here’s how to deploy them

Since the pandemic began almost two years ago, the monster that is Covid-19 has visited every corner of Earth, killing more than 5.5 million people. But we have fought back with astounding speed and vigour, and the situation today is very different from that in early 2020. Ten billion vaccine doses will have been administered worldwide by early February. The Covax scheme has delivered 1bn vaccines to lower-income countries. As a result, global daily deaths from the virus are at their lowest point in more than a year.

So, is the monster slain? No. Covid-19 will not just disappear. Only one human infectious disease has been eradicated from the planet – smallpox – and that took nearly 200 years. Polio is near to extinction, but it has taken a 70-year campaign. Covid-19 may be even more troublesome. Unlike those viruses, Covid-19 has been able to easily adapt to find its way around human immunity (whether from infection or vaccination) so that it can survive. Omicron, or its progeny, will probably be with us for decades to come.

We don’t yet know exactly how the future of Covid-19 will manifest. Perhaps Covid-19 will decline and then return in regular seasonal waves, as with RSV and influenza. It is also possible that outbreaks at other times of year will continue, but get less spiky due to higher levels of immunity in the population.

Have we learned how to fight back? Yes. What has changed most dramatically over the past 12 months is not the virus, but us. Immunity is the armour that means we can now walk the streets again. Vaccines have changed the world. But we must accept that protection against infection is, and will continue to be, incomplete. Over time, as the armour wears thinner, infections will occur again. But protection against severe disease will be largely maintained. We should not expect to return to the vulnerable situation we were in before the vaccines were first made, where we had to hide behind closed doors. (At least, not until the next pandemic, with a new disease, for which we must be better prepared.)

This is why the next phase of the battle against Covid-19 must involve making vaccination available everywhere during 2022. With the huge increase in global capacity since the first doses were give 13 months ago, there really is no excuse for failure.

However, we shouldn’t be overconfident about the universality of vaccine protection. There are still those without adequate immunity, either because they weren’t vaccinated (through choice or access) or because their bodies could not respond to vaccines, and there are also those with other frailties that make them vulnerable still, and on whom the virus will prey.

Meanwhile, for those who remain vulnerable it is critical that we continue to develop and use new treatments for the virus, and to build resilience in our health systems to better cope with our Covid-19 future. Improving capacity in beds and staff will take time, but it is now life-savingly obvious that we must take this action to provide resilience in the face of pandemic threats, and even to cope with a normal year. Here in the UK, the strain on the NHS in normal times is distressing for those of us working on the inside, but has been laid bare for all to see during the pandemic.

While it is unlikely to be necessary, financially viable or desirable to deliver booster vaccines to whole populations regularly, it seems very possible that some vulnerable individuals could benefit from them. We now need detailed analysis of infected patients arriving in hospitals in order to better assess who remains at risk and to decide whether and when to deploy such booster doses for vulnerable individuals. If future variants come and go as rapidly as appears to be the case with Omicron, it will be difficult to make modified vaccines quickly enough, and existing vaccines may have to be deployed. However, if a predictable coronavirus season is eventually established, as with flu, an annual update vaccine is absolutely feasible.

We know how to hone the armour that is needed to defend the world from the harm caused by Covid-19. Vigilance, caution and the tools forged by science are our only route forward.

Comments are closed.