Vaccine-exclusive events or travel must not be instituted—natural Covid-19 immunity urgently has to be included in the debate
Update, April 27 2020: New study just proved my statements below — naturally acquired Covid-19 immunity due to prior infection is in fact ever so slightly more effective at preventing future infections than the Pfizer vaccine: https://www.medrxiv.org/content/10.1101/2021.04.20.21255670v1
I’m very impressed with how quickly the US are rolling out the Covid-19 vaccines, while Europe looks on in wonder. The discussion of compulsory vaccination and vaccination passports emerged very early on as part of the first lockdowns already — and it is now more important than ever to stay realistic and rational. We’ve already seen events exclusively open to vaccinated people, the travel industry will pose the next big questions. But as was the case from day 1 of this pandemic, immunity does not seem to enter the discussion at all. But it must, because studies show long-term T-cell immunity against Covid-19. Whether artificially induced or by enduring the disease — immune is immune.
But first, some background on prior immunity to Sars-Cov2, transmission terminology, and what vaccines are all about.
There has been prior immunity
Studies have shown over and over that parts of the global population have had immunity to Sars-Cov2 due to being previously exposed to related viruses. If someone is immune, they don’t get sick and do not spread the disease. Which logically explains why not everyone got Covid-19 in the past year. The virus spread rapidly enough to infect all of us, but not everybody got sick. “What about asymptomatic transmission” you ask, and “why do governments say that even vaccinated people can still transmit the virus”?
First, I will have to re-iterate what I previously covered in other articles: Asymptomatic transmission rarely happens and has been hyped up over the past year. The situation is as follows: There is a phase between getting infected with the virus and showing symptoms during which you can be infectious — this is called presymptomatic transmission. I.e. you can transmit the virus before you start feeling sick. In addition there is a vast number of people whose symptoms are so mild that they might not consciously notice them and simply forget to tell their doctor — even if you sneeze just once, that’s a symptom, but you might not register it. The combination of those two scenarios has coined the term asymptomatic — however, the term is misleading and there is a great likelihood that asymptomatic transmissions do not actually exist or they happen only very rarely.
Secondly, viral load is directly linked to how infectious you are to other people and to how sick you get. Multiple studies have shown that the milder a patient’s symptoms are, the less likely said patient is to infect someone else. Furthermore, the smaller the amount of virus (viral load) is that you’re being exposed to, the less likely you are to get sick. In that vein, I have also previously explained that getting a positive Covid test result can easily mean that you can no longer spread the virus. This has to do with how PCR testing works.
So, what about the vaccine and the statement that vaccinated people might still spread the virus? The principles of a vaccine and immunity are the same: your body is exposed to the virus and memorises / stores an appropriate defense mechanism should it encounter the same or very similar intruder again. The body is then able to fight off the virus and you don’t get sick a second time. If you don’t get sick, you cannot pass on the disease — I am simplifying here, but the principle holds. If that principle didn’t hold, we could scrap getting vaccinated against any disease altogether. I will also repeat that Sars-Cov2 was never a “novel” virus, which is important for two reasons: 1) The fact that parts of the population have shown prior immunity, means that Sars-Cov2 is a mutation, not an entirely new virus and 2) more crucially, it behaves exactly like we expect a virus to behave, which means that everything we know about vaccines and immunity against other viruses holds true as well. I understand that the Covid vaccines are too new to have long-term data on them, but either they work and make people immune or they don’t. If these vaccines have been approved by the appropriate powers that be as “effective” then it is ludicrous to suggest that they somehow work differently than other vaccines.
(Skip this part, if you’ve read my rants before. I must ask once again, why has the whole world been so, so keen on believing that we didn’t know anything at all about this virus, when ultimately there was nothing novel about it (it was just more virulent than other viruses, but still by no means as deadly as they come*) and it behaved exactly like a regular virus? And why nobody is willing to trust this vaccine, if presumably it ultimately works like any other vaccine? And at the risk of repeating myself again, why were scientist who pointed this out early on beaten down mercilessly? Why does everyone want to panic so badly?)
T-cell immunity should be equivalent to vaccine
So coming back to the idea of the vaccination passport: With the given principles above, naturally achieved immunity has to be equal to a vaccine. Whether you’re immune through vaccination or having had the disease, you’re immune. Long-term immunity against Covid-19 has been shown to come in the form of T-cells. Early studies showed full or partial immunity in people who previously had a virus similar to Sars-Cov2 and newer studies show lasting T-cell immunity in people who went through Covid-19. Should global travel, for example, continue to be restricted, but made easier for the vaccinated, then the population must also get the option to test for T-cell immunity and have those test results mean as much as a vaccination.
There’s also the side issue of discrimination against parts of the population who are not at risk of developing a severe course of the disease, which brings us back to viral load. If you’re not at risk of developing severe symptoms, your viral load is smaller and you’re less likely to infect someone else. In this case the World Trade & Tourism Council suggests: “A blanket vaccination requirement would simply discriminate against non-vulnerable groups, such as Generation X, Z and Millennials, who should be able to travel with proof of a negative Covid test.” While I consider this valid, none of these people have ever mentioned T-cell immunity. A Covid test would have to be taken every time before travelling, the T-cell test you take once, like the vaccination. I just want to make the point that immunity finally has to enter the discussion and immunologist have to start weighing in.
*Sars-Cov2 is actually a pretty meek virus, presumably what made it more difficult to contain is that a huge number of people have had extremely mild symptoms. Check out this comparison between Sars-Cov (2003) and Sars-Cov2 and you realise that severe outcomes are very rare, it’s just that more people are affected. Sars-Cov was much worse, but still nothing compared to truly serious virus outbreaks, like the Spanish Flu or something like Ebola. As always, I am sorry for anyone who has been severely affected by this virus, but as a global pandemic I can only repeat what I’ve been preaching: perspective, perspective, perspective!