So there is no way to throw a net around Covid-19 and tighten it to anything; its animal hosts will always provide an escape hatch. However, it is not really helpful to start thinking about alternative hosts until all potential human victims of a disease have been protected by vaccination – and so far we are not nearly at a distance. As long as people around the world are still waiting for their first photos, Covid-19 will have human hosts to reproduce. And also potentially, to move, creating the kind of variants that now appear around the globe.
This increases the possibility that, as the virus changes, we will have to continue with the vaccines to keep up with it. “I think most people feel that this will probably be in the next few years, we will get a Covid-19 hit,” Alex Gorsky, CEO of Johnson & Johnson, said earlier this month at a CNBC event. “Exactly what that blow will contain, I don’t think we know today.”
If Covid can’t be a disease, we try to gather it quickly – the way, for example, we launch vaccines to fight Ebola outbreaks – it has to become a disease we plan, like measles and the flu. With measles, we start getting vaccinated as children. With the flu, we revaccinate ourselves annually, while adjusting the content of the vaccine to keep up with the viral evolution. We vaccinate against those because they have such a tax. In the last 10 years, the flu has killed between 12,000 and 61,000 people a year in the United States; worldwide, measles kills 140,000 each year.
We have no guarantee that if Covid-19 becomes endemic, it will be as fierce as measles or become lighter. Before the pandemic began, there were six coronaviruses known to infect humans: the original 2003 SARS; MERS, which appeared in 2012; and four that cause seasonal illnesses. The last four, which are now considered endemic, are responsible for about 25% of the colds we get every winter and show that some coronaviruses can become something we don’t like, but we don’t have to be afraid of. (They weren’t always easy, though. One of them was recently linked to a global epidemic in 1889 and 1890 of respiratory disease and neurological problems; it went down in history as “Russian flu” – but that name was a supposed cause, because influenza viruses were not identified until 40 years later.)
A recent paper modeling the potential future of the new coronavirus, written by postdoc Jennie Lavine of Emory University, seeks to predict how Covid-19 might behave in the future, based on data collected from the four endemic coronaviruses, plus SARS and WALKING. He notes that Covid-19 could now reach the status of the four endemic strains, which mainly cause a mild disease on a regular basis – but the result will depend on how circulating disease behaves in children during their first infections. , because these are infections that cause the immune system to respond along the way.
This is the same function that vaccines perform, of course. Our bodies create many types of immunity in response to pathogens; It is too early, says Lavine, to gather the long-term data we will need to know whether Covid-19 vaccination and childhood infection protect both in such a way that any subsequent infections produce only a mild disease.
But it assumes, for the moment, that the virus does not become an infection as mild as a cold, but remains unpredictably dangerous. This perspective makes it more urgent to defuse vaccine nationalism and distribute doses around the world as quickly as possible, not only to protect people from disease, but to deprive the virus of the hosts in which it can move.