If you've already been following Microbial Mondays for a while, you'll have some background knowledge on vaccines, including how well they can work, and why they sometimes don't work so well - plus why I still recommend to get those ones! This post isn't going to cover those topics, but rather take a very quick look at why scientists are searching for a vaccine against SARS-CoV-2 (the virus that causes COVID-19)... But also for other options.
The first thing you should know about vaccines, is that they work. The fact that they work so well comes from literally thousands of years of humans trying to find a way to combat viruses. In fact, the only way humans have ever completely eradicated a disease from the face of the earth, is through vaccination. Interestingly enough, that eradicated disease was a virus, too: smallpox.
Before it was eradicated, smallpox had been devastating humans for thousands of years, and humans had been attempting to find a cure for literal ages. According to this paper, one early treatment was "allowing no fire in the room, leaving the windows permanently open, drawing the bedclothes no higher than the patient's waist, and administering twelve bottles of small beer every twenty-four hours”.
Although that was a little off the mark, people did however notice that once you'd had smallpox, you wouldn't get it again. This knowledge led people to a very early version of vaccination, called inoculation. It was gross. Inoculation involved popping a "ripe pustule" from a smallpox patient and then poking the smallpoxy pus under the skin of a person who'd never had smallpox. In the best case scenario, the pus recipient would end up immune to the smallpox, because that little bit of pus would act in the same way vaccines do: by getting your immune system to run a drill for the real infection. In the worst case scenario, that pus would be too infectious, and actually give the pus receiver smallpox, along with, potentially, a host of other diseases that can be transmitted by body fluids.
That's where a guy called Edward Jenner came in. He was a nerd, and paid attention to the rumours that attested that dairy maids exposed to cowpox were immune to smallpox. Flying in the face of all modern day ethical guidelines, Jenner decided to conduct an experiment to see if this rumour was fact or fiction. In 1796, Jenner found a dairy maid, Sarah Nelms, who had juicy ripe cowpox pustules, popped them, poked that pus under the skin of an 8 year old boy named James Phipps, and waited to see what would happen. Luckily for poor young James, he only developed a mild fever. Less luckily for James, Jenner still had to complete the experiment by infecting the boy with smallpox. Indeed, a few months after he was poked with cowpox pus, James was poked with smallpox pus. Again, James was lucky that science was on his side: he was immune to the smallpox!
Remarkably, that cowpox "vaccine" is what all vaccines are named after. If you're familiar with ancient languages, maybe you've noticed the similarity between vaccine and vacca, Latin for "cow".
Fast forward to the 1990s. Despite this rough-around-the-edges vaccine, smallpox was still around and wreaking havoc. In order to eradicate smallpox, a well-coordinated, well-funded, international collaboration spearheaded by the WHO was set up in 1958. But if viruses are anything, they are tricky - and they take advantage of human social behaviours in order to spread, as you're well aware of now due to COVID-19. Even with relatively high trust in vaccines and pretty darn good international collaboration, it took until 1980 to officially eradicate the virus.
So, after spending thousands of years trying to find a vaccine, it still took us 22 years to eradicate the smallpox virus with a highly effective WHO campaign. Or, 184 years if you count the time since Jenner's cowpox vaccine.
But, what about the current situation? Let's get back to 2020!
The take home message for all of this, is that it will not only take some time for scientists to come up with a potent vaccine against SARS-CoV-2 (although I presume it will not take thousands of years, like with the smallpox vaccine), but it will also take time for us to get the vaccine to everybody. And, that's assuming that the viruses doesn't change too quickly for the vaccine to keep up, like the influenza virus does. Don't get me wrong, vaccines are excellent (I even wear a pin on my winter coat that expresses to the world how much I love vaccines) - but they just take a while to perfect. That's why scientists are are also working very hard on not only vaccines, but treatments for SARS-CoV-2, like the soluble ACE2 I mentioned in last week's post. If we're going to outsmart this virus and get back to some semblance of normality quickly, we're going to have to attack it from many angles. But, that's a topic for next week.
Until then, stay safe and stay home!
~ Alex
Me trying to look cool with my vaccine pin.
Je l'aime, je le vaccine ♡
And, a special shoutout to this paper for being a wealth of publicly available knowledge on the history of smallpox and vaccination!