Vermont is set to become the first U.S state to vaccinate seventy-five percent of its population with at least 1 dose indicating herd immunity.
For most of the pandemic, herd immunity has been a slippery goal. A population reaches herd immunity when a person infected with the Coronavirus passes it on to fewer than one other person, meaning that the virus will no longer pass easily from person to person.
Some people view it a little differently though. Dr. Monica Gandhi, an infectious disease expert at the University of California, San Francisco, considers herd immunity to be when people with COVID-19 are no longer hospitalized.
"Herd immunity is absolutely not eradication," she told Insider. "That is a totally different definition that has been achieved for one pathogen and one pathogen only in the world, which is smallpox."
No state has crossed this milestone yet, but Vermont has administered at least one dose to almost seventy-five percent of its population. Massachusetts and Hawaii have also reached a rate of almost seventy percent of their residents receiving at least one dose.
This is really something we didn't think we'd see a year ago but Vermont's daily cases have shot down to single digits and a spokesperson said: "We have been seeing the beneficial effects of that high vaccination rate play out across our state."
Vermont has recorded only 4 new coronavirus cases per day in the last week. As of Monday, daily tallies had remained in the single digits for the previous twenty-six days... so things are looking up!
Hospitalizations are at a solid rate of less than 5 per day in Vermont too, which is the lowest per-capita hospitalization rate in the country with the state's health department predicting that they'll see fewer than 3 coronavirus deaths in the entirety of July.
But, some states are bringing herd immunity into question as the Delta Variant is spreading widely. An analysis from Public Health England found that Delta was associated with a sixty percent increased risk of household transmission compared with the Alpha variant, though more recent estimates suggest the difference is closer to forty percent.
This just means that more people will need to get vaccinated to prevent the virus in all its strains from spreading so easily.
"Given the increased impact of the Delta variant, it's likely that around eighty-five percent of a population will need to be vaccinated in order to cross the herd immunity threshold," Michael Head, a senior research fellow at the University of Southampton, recently told Insider. "That's going to be difficult to achieve in many settings."
But Gandhi doesn't think that Delta is a major threat to the goal of herd immunity since it hasn't increased hospitalizations.
Delta is also the dominant strain in the U.K, where sixty-seven percent of the population has received at least 1 vaccine dose. Coronavirus cases have increased from around thirty cases to 370 cases per day and unvaccinated people have represented the majority of those hospitalized.
Nevertheless, it's a good sign that the U.S is nearing the seventy-five percent vaccination threshold!