Getting Vaccinated Because… Knuckleheads!

Today I got a COVID-19 vaccine booster, because that’s recommended twice yearly for seniors. I also got an MMR (measles/mumps/rubella) booster because… knuckleheads.

Once More, With Feeling

Today I got my biannual COVID-19 booster, as is recommended by the CDC ^[1]:

People ages 65 years and older, vaccinated under the routine schedule, are recommended to receive 2 doses of any 2024–2025 COVID-19 vaccine (i.e., Moderna, Novavax, or Pfizer-BioNTech) separated by 6 months (minimum interval 2 months) regardless of vaccination history…

Alas, the CDC’s reputation is in tatters, with science censorship and superstition being the order of the day. But, this is still good medical advice from the Before Times.

By my count, and according to my state’s vaccination registry, this is my 10th COVID-19 vaccination shot.

This is me, being responsible both to self and community.

You can do that too, you know.

Ok, Sure… But Why Measles?!

Everybody asks: isn’t measles gone in the US, so we don’t have to worry about that any more?

No, apparently not. From a New York Times article, here’s an annual frequency plot of measles cases from 1985 - 2025. ^[2] Note that the measles vaccine was invented in 1963. ^[3] It took forty years of public health effort to get vaccination levels up high enough to eliminate it in 2000.

But then… look at the bars after 2020: measles is really trying to make a comeback in the US. More accurately, people are really trying to dive into conspiracy theories and disinformation to avoid vaccinating their kids against measles. It’s particularly bad right now in Texas, where we now have dead kids.

This final graph, from Wikipedia on the MMR vaccine, shows this in dramatic form. Note how rapidly the incidence of measles plummeted post-1963, when the vaccine was introduced. Then in the inset, note how rapidly measles has become a revenant disease, because we’re too stupid for words on the subject of vaccines. Yes, individual freedom is important; but the word “public” in “public health” means we have a responsibility to each other, as well! Right-wing disinformation about vaccines is literally killing people.

Also, measles can have a nasty side-effect: immune amnesia, where you lose all the resistance to other diseases you’ve built up over the years, and have to start again. I would not, for example, want to lose my resistance to COVID-19!

Now I was born before the measles vaccines were common, and actually had childhood measles. But… that was a long time ago. That immunity might have faded. Yes, there’s an antibody titer test to tell if that’s the case, but the MMR vaccine is so safe it’s easier just to get vaccinated again.

I want to (a) protect myself against an infection that could be fatal at my age, and (b) be responsible to those around me by not being a spreader. In particular, as the Weekend Editrix goes to visit her elderly mother in Japan, we do not want to give her a virus that would likely kill her, at her age.

First, Do the Math

Why was measles so hard to eradicate, and why is it coming back so easily just because some knuckleheads are too stupid or too gullible to vaccinate?

This is the central truth: measles is the most contagious disease known to humanity. We measure that by a quantity named the basic reproduction number, $R_0$: in an immune-naïve population, how many people get infected from one infected person? If that’s large ($R_0 \gg 1)$, the disease is being rapidly transmitted. If it’s small enough ($R_0 \lt 1$), the disease will die out.

For measles, $R_0 \sim 12-18$, i.e., 1 person would infect on average about 12-18 others if we had no vaccines or other immunity. This is _enormous. COVID-19, for comparison had early in the pandemic $R_0 \sim 2-3$ ^[4], and that was no walk in the park; indeed COVID-19 is still not under control.

Now, consider what happens if not everybody is susceptible, and what fraction of non-susceptible people we need in order to have herd immunity. Let $s$ be the fraction of people susceptible, then the effective reproduction number will be:

$$R_{\mbox{eff}} = s R_0$$

“Herd immunity” is when $R_{\mbox{eff}} \lt 1$, so the infection dies out. Each cohort of infected people is a factor of $R_{\mbox{eff}}$ smaller than the previous. So if that’s less than 1, the disease dies out.

In order to get $R_{\mbox{eff}} \lt 1$, we must have:

$$s \lt \frac{1}{R_0}$$

That is, the number of vaccinated (or immune by recovery from previous sickness) must be at least:

$$1 - s \ge 1 - \frac{1}{R_0}$$

Plug in the measles $R_0 = 18$, and you get herd immunity at 94.4% vaccinated. You really need to vaccinate almost everybody to suppress a disease as contagious as measles!

The good miracle is that we pretty much did that, from 1963 - 2000 as the graph above shows.

The evil miracle is that we are allowing ignorance, superstition, and disinformation to cause people to walk away from that.

If more than 5% of the population fail to vaccinate, then measles becomes a problem for everyone. Here at Château Weekend, we are determined both not to get sick and not to be spreaders, so we won’t be a burden on ourselves or others.

Next, Look at What People Do

Rosenbluth in the NYT article cited above examines the problem of a few knuckleheads bringing the whole public health enterprise crashing down:

Why has the rate of vaccination fallen so much? Part of the answer lies in the Covid pandemic. Conspiracy theories about Covid-19 vaccines made many question the safety of other routine shots. The vaccine-skepticism movement is growing quickly, driven by declining trust in science and rampant misinformation on social media.

She basically points out that people who don’t trust science simply don’t trust reality (emphasis added):

They fear that distrust in science is so deeply rooted and that misinformation is so ubiquitous that many will choose to stay unvaccinated. And they worry that if vaccination rates don’t rise, other preventable diseases like polio will follow.

Vaccine skeptics now walk the corridors of power in Washington. President Trump has questioned the safety of vaccines. So has Robert F. Kennedy Jr., the nation’s top health official, who wrote a book about measles in 2021 saying that outbreaks had been fabricated so the government could “inflict unnecessary and risky vaccines on millions.” There is no cure for the virus, but Kennedy has also promoted unproven treatments: He said this month that doctors had told him about patients who had an “almost miraculous and instantaneous recovery” after they took cod liver oil, steroids and antibiotics. Health officials in Texas tell me such promises may have caused measles patients to delay medical care.

The outbreak in Texas supports the pessimistic thesis. There, even communities plagued by serious illness and death have still largely rejected the M.M.R. vaccine.

So… knuckleheads.

There are only a few ways to avoid getting sick and avoid spreading sickness to others:

• Get vaccinated, so your probability of being sick or being a spreader is dramatically lower.
• Get forcibly quarantined, so sick people are isolated. By “forcibly”, I mean the sort of quarantines used in the 1918 flu pandemic where armed law enforcement officers force you into your home and arrest you if you come out. That’s more or less what’s depicted in this photo, taken 1918-Nov-03 by Raymond Coyne in Mill Valley, California on Locust Avenue: “Wear a Mask or Go to Jail” means law enforcment of masking, quarantine, and so on. (Though I note one knucklehead in the photo is wearing a mask below the nose!)
• Get sick, and…
  • you might recover with measles immunity. Though, given the immune amnesia effect, you might also then have to get all your previous diseases all over again! Or…
  • your death will definitely remove you from the pool of spreaders.

Those are the choices. Vaccination is cheap, safe, and effective; the other choices are none of those things.

The responsible thing to do is self-defense for myself and my family, and to be the responsible sort who does not spread anything I catch. Practically, that amounts to getting an MMR booster.

The Weekend Conclusion

Look, just get COVID-19 and MMR boosters, ok?

(Ceterum censeo, Trump incarcerandam esse.)

Addendum 2025-Mar-18: Sequelae the Next Day

No fever. Just achy and tired. In other words, just like every other Old Man Day, only a little more so.

Easy! Do it.

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Notes & References

1: CDC Staff, “Interim Clinical Considerations for Use of COVID-19 Vaccines in the United States”, US Centers for Disease Control web site, 2024-Oct-31. Downloaded on 2025-Mar-17. ↩

2: T Rosenbluth, “An outbreak”, “The Morning” newsletter, The New York Times, 2025-Mar-17. ↩

3: CDC Staff, “History of Measles”, US Centers for Disease Control web site, 2024-May-09. Downloaded 2025-Mar-17. ↩

4: NC Achaiah, et al., “R0 and Re of COVID-19: Can We Predict When the Pandemic Outbreak will be Contained?”, Indian Jnl Crit Care Med, 2020-Nov. DOI: 10.5005/jp-journals-10071-23649. ↩