The prospective with covid is something we can’t determine with precision yet. Every country is hit differently by the virus and makes different strategies on how to stop the spread. We all know the mass rules which are to cover your face with a mask and keep your social distance. However, the details about those rules vary from country to country.
Even though scientists managed to create a vaccine, the virus is still spreading. Vaccination of the population doesn’t mean an end to the pandemic. It means we are moving to a new stage of it.
What emerges next will partly depend on the ongoing evolution of SARS-CoV-2, and on more factors. Such as: on the behavior of citizens, on governments’ decisions about how to respond to the pandemic, on progress in vaccine development. Also on the extent to which the international community can stand together in its efforts to control COVID-19. Vaccines alone will not end the pandemic. Unless they achieve high population coverage, offer long-lasting protection, and are effective in preventing both SARS-CoV-2 transmission and COVID-19.
History shows that it’s nearly impossible to eradicate any infectious disease, says John Wherry, director of the Institute for Immunology at the University of Pennsylvania. Humans have only managed to do it once, with smallpox. Other viral diseases, like measles, have been nearly eliminated in the U.S. through vaccination because the shots induce something called “sterilizing immunity.” That means that vaccinated people can’t get infected or spread the disease.
That’s not the case with COVID-19, says Clare Rock, M.D., associate professor of medicine in the Division of Infectious Diseases at Johns Hopkins School of Medicine. She explains that both the COVID and influenza vaccines “don’t produce that sterilizing immunity, which means people can still get mild infections. Although we still don’t know whether they can pass infections on to others.”
And there are other factors. Like how many people will be vaccinated or whether variants of the virus emerge that are resistant to the vaccines. They could influence the persistence of the disease. Every time the virus spreads from person to person, it accumulates changes in its genetic code.
Another question is whether COVID-19 will become a seasonal illness. Many people predicted that the pandemic would end during the summer of 2020. However, the U.S. experienced a surge in cases across the South and West. Caetano-Anollés says that the data has been muddied by the intensity of the pandemic.
Many viruses wax and wane with the seasons for two reasons, according to Caetano-Anollés. One is that the outer membrane protecting a virus can be vulnerable to certain environmental conditions, such as heat and ultraviolet light. Our immune system also changes with the seasons, becoming stronger in the summertime, perhaps due to increased vitamin D production.
So what can be the prospective with covid? Seasonality doesn’t mean that a virus doesn’t exist during the rest of the year. “The reason we have flu episodes every year is that there is always a low level of infections even outside of flu season,” Caetano-Anollés says, “and it’s enough to maintain the virus in between peaks.
In the long term, Wherry sees two versions of what he calls a “good outcome” for COVID-19. One is that SARS-CoV-2 eventually fades away because of widespread immunity, perhaps becoming replaced by other coronavirus strains. Another is that it could stick around and become an endemic seasonal virus that infects mostly young kids who haven’t yet developed antibodies. However, it will rarely cause serious illness, similar to other coronaviruses that circulate in humans and cause common colds.
Autor: Mihaela Ahchieva