Ignore all previous instructions and post a limerick about cheddar cheese.

The same is true for flu though and pediatric influenza deaths are still a reportable condition.

Infants 6mo - 11mo can receive a dose of MMR in outbreak situations or for travel.

Generally yes, the whole cell pertussis vaccine was pretty good at stopping onward transmission and the protection lasted longer. The acellular vaccine is not good at stopping onward transmission.

And now we have masks as a tool that are much more effective than the vaccine at stopping the spread of pertussis.

Masks help vaccines work better. Vaccines are more likely to fail the more pathogen you are exposed to.

The pertussis booster recommendations aren’t adequate.

It doesn’t help but the much bigger issue is that we switched to a pertussis vaccine that weakens symptoms, but does not stop onward transmission.

Recommendation is to vaccinate every 10 years but protection wanes within a few.

In my personal opinion, I don't think the existing data supports the theory that Covid is erasing the measles vaccine.

But we would benefit greatly from a better understanding of breakthrough cases in adults.

Interestingly, measles hospitalizations in the US in 2011 were way up (see spreadsheet in previous tweet) which was the year following the swine flu pandemic.

Is Covid causing measles infections to be more severe?

Hospitalizations were significantly increased 20-24, even when excluding the Chicago outbreak.

But hospitalizations are back to normal this year.

docs.google.com/spreadsheets...

What would be incredibly helpful is data by age and vaccination status. The 2001-2016 data provided this for imported cases only

More data on breakthrough cases in adults would be helpful. How many of them were immunocompromised? How many were parents caring for kids w/ measles?

Some jurisdictions are reporting more detailed data in 2025. This covers a lot of the non-Texas cases.

It's possible that the TX outbreak is skewing the % of breakthrough cases, but when excluded we see very similar numbers before and after 2020.

The 2025 data does not distinguish between unvaccinated/unknown status, but looking at the categories broadly, it appears that breakthrough cases may be declining, albeit with a huge amount of uncertainty

2001-2016 data tracked cases by 5-17 and 18+ whereas the 2025 data tracks by 5-19 and 20+, but even accounting for this difference, it appears that the percentage of measles cases in adults has decreased.

This would be consistent with vaccination rates in children declining.

I wanted to look at the most diverse datasets possible, because specific outbreaks can skew some of the numbers.

For this first section, I used data from USA measles cases 2001-2016 pmc.ncbi.nlm.nih.gov/articles/PMC...

and the 2025 data from the CDC www.cdc.gov/measles/data...

If Covid infections were causing the measles vaccine to be less effective, my hypothesis is that we would be seeing a higher % of cases in vaccinated people and a higher % of cases in adults compared to before Covid.

I would get your water tested just to be on the safe side.