When Following the Herd is a Good Thing

I never thought that as a woman in her 60’s, I would have to worry about catching measles. My parents protected us from devastating infectious diseases by getting us vaccinated when we were kids. I am forever grateful for that. But after a leukemia diagnosis in 2021 and a stem cell transplant, my body’s immunity was wiped out. So, after my new stem cells took a solid hold, I had to get my childhood vaccines all over again. No big deal, right? Wrong. The MMR (Measles, Mumps, Rubella) vaccine is the last vaccine I need. But I can’t get it for another six months. The reason? I have been on a medication for the GVHD (graft versus host disease) that I got from the stem cell transplant. That medication suppresses the immune system. Luckily, I was able to go off it last September. But I must be off that med for an entire year before I get the MMR vax because it is a weakened live virus vaccine.

In years past, I wouldn’t be concerned. Back in the year 2000, the United States had effectively eradicated the measles thanks to the vaccine. Once a society achieves above a 95% measles vaccination rate, herd immunity is achieved. You probably have a sense of what herd immunity means. When enough people become immune to a disease, through vaccination or a previous infection, it makes it hard for the disease to take hold and spread. When enough people are immune, even people who cannot get the vaccine are protected. Getting the measles vaccination protects not just the person who gets the vaccine, but their families, friends, and their community. It protects that infant in the grocery store with her parents, who’s still too young for vaccination. It protects that cancer patient, out for some much-needed fresh air in the park or at lunch with friends, whose immune system is weakened because of chemotherapy. It protects the very young, the vulnerable, the old, the sick who are healing and recovering. People like me – and probably some of you too.

You may hear some people say that we should achieve herd immunity “naturally”. For that to happen, we would need to wait for enough people to get the disease and become immune. But there are several problems with that. It would take a long time for enough people to get sick to achieve that minimum 95% immunity rate. Also, some people would get so ill that they would need hospitalization. Not only would they feel really bad, but there would be increased demands for hospital beds and medical personnel. And some people would die. Vaccination is much more effective in getting the herd to immunity without sacrificing human lives. Vaccination is a team sport.

Sadly, because of influential, convincing-sounding, anti-vaccine conspiracy theorists we have lost our once solid herd immunity to measles. Measles is not a harmless disease from which most people recover. Researchers have discovered that even after someone has had the measles and recovered, there is possible long-term damage to their immune system, making them more likely to get other infectious diseases.

Measles is the most contagious of human viruses. One person with measles can infect another 18 people. Each of those 18 people can infect another 18 people and so on. So, you can see why it spreads so quickly. The recent measles outbreak in Texas that started in one small, isolated Texas community has had the most cases – with 146 cases at last count. Tragically, one 6-year-old child died. Eight other states have now reported cases: New Mexico, Alaska, California, Georgia, Kentucky, New Jersey, New York, and Rhode Island. Of all the people who have gotten the measles, most have been children. And 20% of cases were so severe that they ended up in the hospital. Most cases have been in the unvaccinated.

So, just as I was starting to feel more comfortable not wearing a mask in public places and feeling like an almost-normal person again, I will be masking up in many public places.  And I’ll be counting down the days until September comes when I can get my MMR vaccine. I know I sound sorry for myself, and I admit I am. But I feel the most sorrow for the children who will get sick, some severely, as this outbreak continues. Sometimes, following the herd is good.

Beth Kitchin PhD RDN