What should I know about Covid-19 mutations… and should I panic?
Short summary: Don’t panic, but vaccination is not a magic bullet.
I’m going to refer to the mutations Eeek and Ken in this article, both of which are changes to the covid-19 genes that help the virus escape antibodies a small amount in immune/vaccinated people. If you want to know more detail, here’s another in depth article [coming tomorrow!].
Will the Vaccines Work Against the New Variants?
Firstly there is no reason to think the vaccine won’t be successful against all the variants. Success in vaccination means you won’t get seriously ill, which you can read about in this article.
Vaccines can still be very successful even if their efficiency is as low as 40%. We’ve been hearing about 90% efficiency from covid19 vaccines but those kinds of numbers are very unusual in vaccination generally. So even if mutations reduce vaccine efficiency by 10–30% this isn’t as awful as it initially sounds. In addition, if a vaccine can’t stop you getting mildly sick but can stop you getting seriously ill, this is described as “ineffective at preventing any disease” but you can imagine this would still completely crush the death rate! So be suspicious when you hear “ineffective” in the media, especially in relation to mutations.
There is a big caveat to all of this — vaccines probably won’t be able to completely stop covid-19 spreading around.
What happened in Manaus, Brazil
In Manaus, Brazil, there was a first wave of covid-19 in 2020 where an estimated 76% of the population got the virus and are now immune. This is putting “take it on the chin” strategy to the test, and enough of the population is immune to protect everyone. Contrary to expectations, however, Manaus got an even worse second wave in 2021. What happened?
No one knows for certain, there are plenty of theories [8], and it could be the estimates of immunity were too high. The Brazilian variant was discovered to be dominant there and it has both Eeek and Ken which has been shown to escape antibodies somewhat in immune people. It could be that even though an immune person is still immune to covid-19 with these mutations, it might be it can replicate and spread a little before the immune system is able to destroy it completely. In a few cases, reinfection of an immune person has been confirmed, and so a few people have become sick twice with covid-19 in Manaus.
When someone catches covid19 and fights it off, their body is filled with floating antibodies that act like landmines and explode any covid-19 virus that enter and before it can invade cells. This kind of immunity is called sterilising immunity, and lasts up to 5 months after recovery. Once sterilising immunity has worn off, you can still have “effective immunity” which is where your body remembers how to make those antibodies [7]. The alarm will sound and after a little while, hours to days, the virus will be annihilated. You wouldn’t have any symptoms and wouldn’t know. However, the virus has a bit of a chance to invade your cells and replicate, and there’s even a possibility you could have spread it to others. Vaccines give you effective immunity for free (but probably not sterilising immunity), and so in the same way you could be vaccinated and catch covid-19 and not know, and possibly even spread it.
Eeek and Ken gives the virus a bit more of a chance against the antibodies, and so it might replicate for a bit longer in immune people. We call this “antibody escape”. As so many people were immune in Manaus, Brazil, this is likely why the these mutations became dominant in the area —as Darwin taught us, only the fittest survive!
Vaccinated/immune people provide selection pressure for new mutations
Imagine you’ve been vaccinated and you’re coughed on and the original covid-19 virus enters your body. Your body makes antibodies and cleans it up before it spreads out of you and the virus has been effectively “killed off”. In a population who is 65% immune, this specific virus has no chance at all and will be wiped out quickly. However, imagine you instead caught a covid-19 variant which contains some “antibody escape mutations” like Eeek or Ken or something brand new. This virus could maybe replicate enough to escape your body and maybe spread to someone else, even if they are also immune. Over time all the original covid-19 viruses will disappear and only these variants with mutations in their genes will have survived. Remember, no one is getting ill in this scenario!
If no one is getting sick then what is the problem? Every time a person catches a virus and it replicates using their cells, the virus gets to roll the genetic dice and there’s a chance a new mutation will arise. Covid-19 seems to have a current rate of 1 mutation per month, which is very slow. Replicating in an immune person is a bit like putting the virus and its genes to the ultimate test, or the thunderdome. Only the best mutations will survive. Any random mutation that helps it escape the antibodies long enough to spread to someone else will be hugely successful and will quickly spread throughout the population. In evolution, we call this a high selection pressure.
The worst case scenario is a mutation that completely changes the spikes on the outside of the virus, as the immune person’s antibodies would suddenly be useless. And then immune and vaccinated people would get ill.. and we’d have covid-21.
So do we panic!?!?!
Again, absolutely not. Covid-19 mutates really slowly, and the chance of a jackpot-vaccine-beating-mutation-combination arising is very low. But of course, with high enough numbers low chances suddenly get more common. Winning the lottery after you bought 1.3 billion tickets is not impressive. To eradicate this disease and prevent a new “strain” [9] — so covid-21 or covid-22 — then we need to globally stop covid-19 replicating in people’s bodies. As I’ve explained, vaccines can’t do this completely. Vaccines are the best possible tool for preventing people dying and getting seriously ill, and it will still have a big impact on reducing spread. But it isn’t a magic bullet.
How do we do prevent new scarier mutations?
The best way is to vaccinate people as fast as possible. This acts like throwing water over a smouldering fire, giving it no chance to spring up again. The UK is doing well in this, but we do need to think of this problem on a global scale. 100% vaccinated UK won’t be any good if a vaccine-beating strain appears in India or Finland, as it will spread worldwide. Keep putting political pressure to donate our spare vaccines as quickly as possible to less developed countries.
The vaccine scientists are already on the case and boosters will be available eventually that deal with Eeek and Ken and whatever comes next. However, changing vaccines require time and we can all do our part to help in this fight. We need to give the scientists enough time to fight back against the mutations.
We need to keep genetically testing as much as possible to keep ahead of any new mutations, and again the UK is doing very well at this. Hopefully the rest of the world will also improve. Our country desperately needs a better test and trace system that can fight against new variants spreading.
You can try to spread a different contagion — vaccine trust, especially with non-Brits where vaccine hesitancy is higher. For example, currently 40% of French people say they will definitely not take the vaccine. Most fears about the vaccine are that you will catch covid-19 from it and that it contains unhealthy chemicals. Even if you know they’re untrue, can you answer why if asked? Posting on social media about getting the vaccine can provide a healthy level of peer pressure too.
What should I do if I have been vaccinated?
Vaccines are the best weapon against this disease but understanding the limitations and nuance is quite critical. If you have been vaccinated, remember you can be still a risk to others! You might be able to spread it, and your body could be the thunderdome where the newest version appears.
The best thing to do is to keep an eye on how many cases of the virus are in the UK. It’s unlikely we’ll get rises in cases in the summer so take advantage of that, but perhaps modify your behaviour in response to changes in the data in your area. Soon we will be able to meet in small groups again, thank f***, but consider spreading out your socialising so you have a few days in between mixing with new people. Ventilating rooms and masks are still so important and are worth it for a bit longer, and standing far away from random people in shops, and not touching your face.
While we have a big proportion of unvaccinated people as well as vaccinated people, this is actually more dangerous for new mutations compared with no vaccinated people. If no one was vaccinated, the original covid-19 can spread around and there is no pressure to gain new mutations. If everyone is immune, then the virus is smothered quickly and has no chance to roll the dice. If half are immune and half aren’t, then the virus has a safe place to stay alive (the unvaccinated) and also plenty of opportunities to try out the thunderdome (the immune) and possibly win the jackpot. Of course, half vaccinated population will have an amazing impact on the death rate and hospitalisation rate.
If you get a vaccine and have the opportunity to travel to a country with low vaccine uptake, then do think about this problem carefully and make informed decisions. Consider if isolating after you return is a viable option, even for a few days.
In conclusion, be sceptical of scaremongering or sweeping headlines in the press as there is a lot of misinformation and mistakes. The data suggests we have turned a corner with deaths and that can’t be understated as an achievement. I don’t know how we communicate the more difficult nuances of why modifications to behaviour are still really important even as cases drop and even if most people are vaccinated. The problems of antibody escape from mutations is hard to explain.
References:
[1] The gene mutation is actually called N501Y and it describes a change from the amino acid asparagine (N) to tyrosine (Y), so we can give it a nickname using those first and last letters: Nelly. These nicknames help us distinguish the mutations more easily than a string of numbers and letters.
[2] https://www.imperial.ac.uk/media/imperial-college/medicine/mrc-gida/2020-12-31-COVID19-Report-42-Preprint-VOC.pdf
[3] https://covidreference.com/variants
[4] https://www.biorxiv.org/content/10.1101/2021.01.07.425740v1
[5] http://biorxiv.org/lookup/doi/10.1101/2020.11.06.372037
[6a] https://www.sciencemag.org/news/2021/02/south-africa-suspends-use-astrazenecas-covid-19-vaccine-after-it-fails-clearly-stop
[6b] https://www.biorxiv.org/content/10.1101/2021.01.27.427998v1
[7] One thing to note: many people have probably caught covid-19 and fought it off, but haven’t gained effective immunity because their immune system didn’t have to fight very hard and so didn’t commit it to memory (for example, if there was very low viral load).
[8] https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)00183-5/fulltext
[9] A strain is a big overall difference in the virus. Different variants are a bit like having different eye colours, but a different strain is like a different breed of dog.
