Yes, herd immunity is possible through vaccination, NOT infection, doctor says

The words 'herd immunity' have been thrown around all year as the nation and the world try to figure out how to fight COVID-19. What does it mean, exactly?

Well, for starters, it does not mean everyone gets sick and they're immune to the virus. That's not realistic. 

Dr. Varsha Moudgal, Chief Medical Officer, St. Joseph Mercy Livingston, is an Infectious Diseases Specialist. She says we need to look to the flu for a bit of guidance.

"What herd immunity is - is when you have a large group of people, if you can have a critical number of people that are immune to an infection, then the infection doesn't spread from person to person so some people are not immune in the middle of this herd of people, then they can still be protected because the infection isn't spreading in the community. that's what herd immunity means," she said.

The safe way to get to herd immunity is through mass vaccination, NOT mass infection as some people are suggesting. As Dr. Moudgal explains, trying to get herd immunity without a vaccine is costly on a number of different levels.

"It's difficult to predict who would get extremely ill and who would not so that's another problem because I've also heard of these so-called COVID parties like the chickenpox parties of the past. Those don't work either because even some young people without any medical conditions can get extremely ill and in order for the herd immunity to work you'd have to get up to numbers that are not really achievable without harming a significant percentage of the population. That's why the herd immunity aspect won't work with COVID," she said.

When a vaccine is used to build immunity, that's a safe way to create herd immunity because people are building protective antibodies without spreading disease.

"So in a family, if you have one person who has a lot of underlying medical conditions, if someone else gets sick and brings the flu into the family then that family can get extremely sick. So if all of the family members get vaccinated against the flu, then they can protect their loved one," Dr. Moudgal said.

So, the doctor makes it clear that, yes, herd immunity is possible with the flu vaccine and it's safe and effective. However, she says without a vaccine that's widely available, it's not possible for COVID.