Herd immunity: The goal in race to slow down coronavirus

Social distancing has helped as researchers pursue treatments and vaccines

Herd immunity illustration. Human crowd forming a big target symbol on white background.

The term “herd immunity” has a long history. Sooner or later, that history most likely will include slowing down the coronavirus.

Because there is not yet an effective vaccination, it might not happen as quickly as everyone would like. It remains, however, the ultimate goal as the world continues its battle in harnessing the pandemic.

“This virus is three or four months old, so we are like new parents,” explained Dr. Avish Nagpal, a specialist in infectious disease at Sanford Broadway Medical Center in Fargo, North Dakota.

“We are learning on the go. We need to know more about the virus. We really hope that, once you get the infection, it behaves really like other viruses and you don’t get a re-infection.”

Hearteningly, helping establish herd immunity is a history book full of success stories.

Herd immunity tackled measles

For instance, an estimated 3 to 4 million people were infected by measles annually in the United States alone in the 1950s. Because of herd immunity established by widespread vaccination, it was largely gone by the 1970s.

“Let’s say somebody gets the measles and they’re playing on the playground,” Dr. Nagpal said. “If the other kids are immune, you break the chain of transmission because the person with the measles can’t pass it on.”

That immunity can come naturally — assuming those who contract the virus will not get it again — or, ideally, via a vaccine.

“It can’t jump from person to person, and it can’t get to you,” Dr. Nagpal said. “It’s like an obstacle course for the virus.”

A vaccine by 2021

Establishing those conditions for the coronavirus is a work in progress. Obviously, there is no vaccine yet. On April 30, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said having hundreds of millions of doses of a vaccine available by January 2021 was “doable.”

Historically, vaccine development has taken significantly longer.

In the absence of herd immunity, social distancing has made a significant impact, according to Dr. Nagpal. As science continues on with a search for treatments and vaccine, following guidelines has bought health care systems valuable time in taking worst-case scenarios out of play.

In the Upper Midwest, where Sanford Health is based, those efforts have flattened the curve. That is, avoiding situations that would overload health care systems to the point where proper treatment would in some cases not be possible.

Social distancing making a difference

“Every day that we keep the curve flat is a win for us,” Dr. Nagpal said. “It means we can ramp up manufacturing, we can ramp up personal protective equipment and supplies. … We can add to hospital capacities, and we can discharge patients who are getting better. We have bought ourselves some time with the sacrifices everyone has made.”

Some countries have attempted to reach herd immunity by letting nature take its course. It comes at the risk of pushing health care systems beyond their capacities.

“The speed and severity of this pandemic is just unprecedented,” Dr. Nagpal said. “Our hospitals and our health care systems are not built to handle these kinds of pandemics.”

Vaccinations decline during pandemic

Just as cooperation is necessary in social distancing, it is also a vital part of establishing herd immunity. When vaccinations are available, people have to participate.

National trends indicate significant dips in parents seeking vaccination of preventable diseases for their young children during the pandemic.

The dramatic decline in vaccinations suggest parents have decided these procedures are not urgent. Providers would not agree.

“The American Academy of Pediatrics has put out several articles indicating they’re very concerned about vaccine-preventable illnesses causing outbreaks,” said Dr. Vanessa Nelson, a pediatrician at the Sanford Children’s Clinic in Bismarck, North Dakota.

“In Bismarck, we’ve seen whooping cough in the last month. That can be fatal to infants. For all of the other vaccine-preventable illnesses, as well, we want to avoid outbreaks.”

In the month of April alone, vaccination rates dropped off by 50% throughout the Sanford Health system from a year ago.

Getting caught up

“Think about just the childhood vaccinations for things like measles, mumps, rubella, chickenpox,” said Sanford Health chief medical officer Allison Suttle, M.D.

“If those vaccinations don’t get caught up — and we have more people not vaccinated — we could have a measles outbreak coming up this fall. That’s in addition to influenza and other things. Those vaccinations are critical. A 50% drop is very significant.”

While research involving a vaccine moves along at an accelerated pace, so, too, does the quest to develop treatment that would shorten the duration of the virus. Shorter duration equals less probability someone can pass the infection to others.

“Hopefully we’ll get a therapeutic drug before the vaccine — before the end of the year,” Dr. Nagpal said. “Even if it is 50% efficacious, we’ll take it. And hopefully we’ll get a vaccine, hopefully early next year or in the middle of next year. Even if it’s 50% effective, that’s a win.”

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Posted In Bismarck, Coronavirus, Fargo, Immunizations

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