TThe new variant of the Covid-19 virus first detected in India comes in three forms: B.1.617.1 (abbreviated as variant 1), B.1.617.2 (variant 2) and B.1.617.3 (variant 3). Each of these has a slightly different genetic makeup. The one that is booming in England is variant 2.
There is good news and bad news about this variant, based on the limited data we have. The good news is that we believe it does not contain the 484K / Q mutation which has been linked to some degree of vaccine resistance. So the current AstraZeneca and Pfizer vaccines should work relatively well against it, and at least protect most of us from serious Covid-19 disease and death. We have no evidence of this variant causing more severe disease, either – at this time.
The bad news is that we believe all of the ‘Indian variants’ contain the L452R mutation, which is also found in the ‘California variant’, and which appears to confer some vaccine resistance and possibly more transmissibility. Variant 2 appears to be spreading rapidly in the English population – perhaps even faster than the existing ‘Kent variant’ of B.1.1.7. It also contains a new mutation, and we don’t yet know what that does – it may improve transmissibility as well.
What does all this mean, as England plans to open more on May 17th and then June 21st? More data is needed from laboratory and actual population studies, but in the meantime you might think of it like this. Some virologists like to use the metaphor of an immunological landscape. Imagine a savannah, with meadows, hills and a mountain in the distance. We are the prey – say antelopes – while the virus takes the form of predators, such as hyenas or lions.
If we are not immune, you might see that we are feeding on low level grasslands. If the virus comes in a form that spreads faster (like the Kent or Indian variant), we might imagine it as a faster predator chasing us.
If we are vaccinated with at least one vaccine dose of a fairly effective vaccine (for example, AstraZeneca or Pfizer) or if we have natural immunity, we could be standing on hills of different heights, depending on the effectiveness of our protective immune responses (not everyone will respond to the vaccine). This makes it more difficult, but not impossible, for predators to catch us.
This analogy is not exact but can be very useful at this time, in that not all antelopes pursued by these predators will die; in fact, most of the time the antelopes escape.
Most unimmunized people in the UK will not be exposed to the virus at this time when the prevalence of the virus is low. And where these unimmunized cases do are infected, most only contract mild Covid-19 disease (the equivalent of a few scratches and bites). All Covid-19 vaccines can prevent serious illness and death, but they may not protect you against mild or moderate illness.
However, new variants can always emerge that are able to bypass the vaccine or natural immune barriers – unless we continue to readjust our Covid-19 vaccines (climbing higher hills) to stay out of reach.
How can this analogy help us understand what can happen when we open up more on May 17th, as the Indian variant spreads to parts of England – and when most under 40s and some over? 50-year-olds not yet vaccinated?
If the Indian variant really acts with improved transmissibility then after May 17th we will have cheetahs chasing larger herds of antelope across the grasslands (i.e. unimmunized under 40s) then that we are open to dining and other activities. Most of these antelopes will escape consumption, although many will have scratches and bites when they attempt to escape (which equates to mild to moderate disease for the most part self-limiting). This can take the form of a long Covid, a risk that unvaccinated young people will need to seriously consider in the weeks to come.
Some of these variant 2 cheetahs may have some ability to climb (due to partial resistance to vaccines with the L452R mutation), but again, most of the antelopes that are hunted on the hills will still escape the dead and will suffer just a few scratches and bites during their escape.
At the moment, it’s too early to tell if mix-and-match vaccine combinations are so protective they can put us on top of the mountain – beyond the reach of most vaccine variants currently in circulation. But clinical trials are continuing and we might find an optimal combination, at least for a while – until the next variant comes along.
What does that mean, practically? Try to speed up the vaccination schedule to give at least one dose of the vaccine to all those who have not yet been vaccinated in the 18 to 50 year age group. Surge testing is unlikely to control this variant 2 virus, so masking and social distancing will need to be continued to reduce the spread of the virus as we improve vaccine coverage from the first dose.
We know that with any rapidly spreading variant there will be more serious cases requiring hospitalization, so we need to prepare the NHS teams for this – especially as they are trying to catch up with all non-Covid medical backlogs. . If we truly follow a ‘data, not dates’ approach, unfortunately we may need to consider postponing the proposed relaxation dates to May 17 and June 21 – if the number of people requiring more severe Covid-19 hospitalization begins. to increase too much.