When vaccinated individuals were invited by the Centers for Disease Control and Prevention to unmask in May, the world breathed a sigh of relief.
Things were finally getting back to normal, or so it seemed. Now, with UW-Madison re-instituting a mask mandate on campus as of Aug. 5 and Dane County Public Health recommending that everyone mask up regardless of vaccination status, it feels in many ways like we’re right back where we started in March of 2020.
The Delta variant of COVID-19 has raised health concerns for both vaccinated and unvaccinated individuals — but why? Shouldn’t a vaccine protect you from infection?
The presence of the Delta variant is “directly correlated to the presence of unvaccinated individuals,” said Dr. Richard Zane of UCHealth. People who are unvaccinated either due to personal preference of a medical condition, such as autoimmune diseases, can act as a hotbed for virus evolution, allowing more infectious variants to evolve. These variants can then go on to infect vaccinated individuals because of their evolved traits.
Just as with the Alpha variant of COVID-19 that swept the globe last year, the Delta variant is transmitted through respiratory droplets that are spread when infected individuals speak, cough or sneeze. Masks prevent the spread of these droplets, thereby drastically reducing infection rates. The CDC recommends multilayer masks and advises against the use of single-layer masks like neck gaiters.
Since introduction, none of the available vaccines have been shown to be 100% effective against infection, though two-dose vaccines have been proven to decrease the infection and hospitalization rates dramatically.
So, do we need a new vaccine? Not yet. The currently available vaccines are still effective against preventing infection and illness caused by any worrisome variants. However, countering diseases is always something of a medical arms race. Just as bacteria evolve to be resistant against antibiotics, viruses evolve and mutate to gain resistance. Luckily, SARS-CoV-2, the virus that causes COVID-19, is not a particularly fast-mutating specimen, with new variants popping up more slowly than flu variants. This, along with continued vaccination worldwide, should slow the need for a new vaccine.
A full course of COVID-19 vaccinations still provides significant protection against infection and serious illness. However, the vaccine also decreases the percent of those infected who become symptomatically ill, meaning it may be harder to catch cases before they spread. As such, the best defense against the Delta variant is to get fully vaccinated if possible, while continuing to wear a face-covering in public spaces regardless of vaccination status. And, of course, wash your hands!