The vaccine programme in the UK has now reached more than half the UK population, bringing with it a sense of optimism about a virus-free future. However, despite the road to recovery being well under way, it’s important to recognise that the data relating to each vaccine’s overall effectiveness and long-term benefits is only preliminary. As a result, the constant monitoring of progress surrounding the vaccine rollout is essential for making informed decisions in the future.

How do current vacccines perform against variants?

This is one of the big questions as we see an increase in the number of mutations of COVID-19 and concerns about the effectiveness of existing vaccines continue to grow. Whilst there is still only a limited amount of data available, clinical trials that have been carried out show that existing vaccines have the ability to protect individuals against the currently known variants. One Pfizer study on the B.1.351 variant found that the vaccine remained 100% effective against severe disease and death - and the same was true in another study focusing on the B.1.1.7 variant. There is also a range of real-world evidence to show that this is also the case with the AstraZeneca, Moderna and Johnson & Johnson vaccines. It’s also worth noting the falling number of cases and hospitalisations within the UK where vaccination levels are high.

Variants and the immune system

 The first thing that is important to note is that the presence of antibodies isn’t the only factor to take into account when it comes to working out how protected we are against the virus. Also important are the T-cells, which also mount a defence against pathogens entering the body. All of the clinical trials that have so far taken place on all the vaccines found that T-cells rise in numbers in those who have been vaccinated. These T-cells can identify parts of the virus on infected cells and work to eliminate them. Research has also found that T-cells can identify 52 parts of the virus, so even if COVID-19 continues to mutate, there is still a high chance that it will still be recognisable to the T-cells in those who have been vaccinated. The main reason we have heard more about antibodies than T-cells in recent months is because antibodies are much easier, and cheaper, to monitor. However, T-cells allow individuals to remain protected against viruses for extended periods of time. For example, their protection can last for decades, as the immunity you get from specific measles T-cells lasts up to 34 years. Moreover, T-cells in SARS patients from the 2003 epidemic have so far lasted 17 years.

There’s no doubt that COVID-19 represents a huge challenge to global healthcare. This is especially so now that variants have entered the picture and we are increasingly dealing with mutations. However, there is also a growing body of evidence to show that the vaccines currently in circulation could help our bodies continue to repel the virus for many years to come.To find out about the various COVID-19 vaccines and their implications, be sure to read our previous blog ‘The COVID-19 Vaccine: What it means for you’ for more information.