Countries around the world are currently ‘opening up’ and reducing efforts to control the spread of Covid-19. This means that international travel is once more possible including to previously closed destinations such as Australia. Meanwhile, we are seeing huge surges in covid rates globally, as the Omicron ‘stealth variant’ takes hold. So, is the pandemic nearly over?
For most countries, the move to open up follows a huge effort to vaccinate their populations, with some now looking at a further booster for high-risk individuals. In the UK that means a spring booster for those over the age of 75, those in care homes, and those 12 and older who have a weakened immune system.
In the UK, we are seeing an increase in case numbers despite the drop in testing. Tim Spector at the Zoe covid study reports that daily rates are setting new UK records and sadly it is starting to spread to the more elderly. The Coronavirus dashboard confirms that the increase in case numbers is leading to an increase in admissions and many hospitals like my own in York have significant numbers of patients with a diagnosis of covid. Sadly, this is hampering efforts to reduce waiting lists as it affects our ability to maintain elective surgery activity.
So the answer must be that the pandemic is far from over.
The rise of Omicron BA.2 ‘stealth variant’
Omicron has taken over from Delta across the globe and several subtypes have been identified. The original BA.1 is still reported in most numbers worldwide. But there is a new subtype termed BA.2 that we know is slightly more infective than BA.1, and in many countries (UK included) this subvariant is now most common.
Over the past two years, each new variant has taken over by being more infective. Alpha was 50 percent more infective than the original strain, Delta increased infectivity by a further 50 percent, and the original Omicron was again more infective. Now with Omicron BA.2 – dubbed the ‘stealth variant’ – we see countries that have previously had a good record of control such as China, struggling to manage; studies suggest it is at least 30 percent more infective than Omicron BA.1 and is better able to infect vaccinated people.
In many ways we were lucky with Omicron BA.1, as although it was more infective, it was less deadly than Delta. Studies showed that unvaccinated people are up to 25 percent less likely to be hospitalised or die from Omicron BA.1, though as the World Health Organization stresses, it is still very serious. We were also lucky that though it made the vaccines less effective, they still offered protection against serious disease.
Evolution of the coronavirus
I use the term ‘lucky’ as contrary to the narrative of many pundits, this milder evolution was just by chance – there is no evidence that viruses evolve to be less deadly. This is especially true in a virus that spreads in the days/weeks before it leads to a fatal outcome, there is no selective advantage in evolving to be less deadly.
When this virus mutates it is the more successful changes for infectivity that will win the day – so how lethal it is just depends on the overall effects of those changes on our bodies. The next variant could be as bad as or even worse than Delta. As yet it’s not clear whether Omicron BA.2 is more deadly as well as being more infective, though a study from Japan does suggest this might be the case.
When we consider the effectiveness of the current vaccines used in the UK, it is important to remember they were developed to vaccinate us against the original virus. They have remained effective against Alpha, Beta, Gamma and Delta variants, but as the virus mutated then the protection lessened to a degree, especially now with the Omicron variants. Vaccinations still protect against the development of long covid, and reduce the need for hospitalisation and ICU admissions, but we can still experience a covid infection and pass it on to others.
Monitoring the virus
This virus will continue to mutate and evolve and variants that are more infectious will take over. This means that at some stage it is likely that a new variant will emerge, that is so different it can escape the immunity provided by vaccination and previous infection. We now monitor and report reinfections in recognition of the fact that many people who have had covid from a previous variant are being reinfected with Omicron BA.1 or BA.2.
Free testing ends on 1 April due to the cost to the Treasury of running the service. Currently over a million PCR tests can be performed a day and we have free access to lateral flow tests. From April we will have to pay for lateral flow tests and the number of PCR tests being performed will be drastically reduced.
Experts are concerned about both aspects, as the loss of free lateral flow tests will disadvantage poorer communities – making it less likely that people will test and isolate. The reduction in PCR testing means less samples being reviewed nationally and so the concern is that this will reduce our ability to pick up new variants.
What next for the pandemic?
The virus will continue to mutate/evolve as the infection continues to increase in waves across many countries. As explained, the successful mutations will be those that are more infective and these will take over as the dominant strain. In countries with high vaccination rates and high numbers of previously infected individuals then the successful strain will be one that can evade our immunity.
Thinking the pandemic is over and dropping simple protections like using masks indoors, improved ventilation and HEPA filters means we are seeing another wave of the virus. Opening up and increasing international travel will further increase exposure of our population to different strains and so it is likely that a new variant will hit us that we are no longer immune to. This might come from abroad or be ‘home grown’; both routes have happened previously.
However, it is not all bad news. We have learned a lot over the past two years about protecting ourselves, we know much more about how to treat this disease, and we can change the vaccines. Indeed, claims have been made that current vaccines could be updated within 100 days. There are also new vaccines coming through that offer protection not just linked to the spike protein, and these may well remain effective despite new variants.
Hopefully we will also have learned lessons and be able to bring in mitigations much more quickly – so free testing, support for those isolating, use of FFP2 or better masks, improved ventilation and HEPA filtration. We know these work and they prevent the need for lockdowns, which no one wants.
The message from the World Health Organization is that this pandemic is far from over and we in the UK need to be prepared to respond to any new variant.
