Question: If there were no available vaccine for Covid-19, would we be able to stop the virus? How much time would it take for the virus to vanish from the Earth?

Sabrina Slater answered on 18 Jun 2020:

Hi David,
Interesting question! Have you heard of ‘herd immunity’? This is when about 80% of the population (or more) have been exposed to a particular disease and are immune. This means that every time one of these people in the 80% group come into contact with the disease-causing virus again, they fight and destroy it. When this is occurring all day every day, the remaining 20% of the population have much less chance of catching the disease, because it’s being “mopped up” by this 80%. So, THEORETICALLY, in the past we may have been able to get rid of viruses like this. However, there are a few tricky things about Covid-19 that mean herd immunity won’t work:
1) there are people who have been infected more than once, or people who have had the virus but don’t seem to have any protection against it
2) Covid-19 kills a lot of people! Relying on this as a strategy means knowingly letting lots of people, particularly people over 50, die. Obviously we can’t let this happen! If people who are exposed don’t live to be part of the 80%, they can’t be part of the ‘herd’ required for herd immunity.
3) Because Covid-19 is a relatively new virus, when people do become immune to it, we don’t know how long this immunity lasts – weeks? Months? Years? Lifetimes?

This is all very doom and gloom but there are 2 MUCH easier solutions to wipe Covid-19 off the planet, and they both basically rely on stopping the virus spreading from person to person. If the virus has no humans it’s able to infect, it can’t survive out in the sun! The first half of this solution is cleaning surfaces, your hands, your face, and wearing a mask so that we don’t breathe virus particles all over each other. Scientists estimates this alone can cut the spread of the virus in half at the minimum! The second half of the strategy is treatment for those who are already infected, and this can happen most quickly through drug repurposing. This is when medical workers and scientists give patients drugs that already exist (so we already know the side effects of them and how they work) to treat Covid-19. Not random drugs of course, drugs that we have good reason to believe will make people better.

Hope that answers your question!