Why do some people think that vaccinated people can often spread measles?
The usual suspects…
Do More Vaccinated or Unvaccinated People Spread Measles?
The real truth is that children and adults who are either partially or fully vaccinated very rarely spread measles to others.
And that’s actually what the study that Sayer Ji is posting about says!
Of course, he is misrepresenting what the study says to try to get you to think that those who are vaccinated are more commonly spreading measles than they really are.
That’s why he says that nearly a third of transmitters ‘had received two or more doses,’ etc.
In reality, the meta-analysis looked at 33 outbreaks/studies from 18 countries and found that:
812 cases could be traced back to someone who was vaccinated
70 people were thought to have transmitted measles to someone else, leading to 237 secondary cases
22 of the 70 people were fully vaccinated
And they concluded that “Measles transmissions from vaccinated cases, although relatively uncommon, must be considered in public health investigations, as such transmissions can contribute to outbreaks.”
But the study is not saying that the transmission rate for measles from someone who is vaccinated is 7.9%!
What else?
Many of the downstream measles cases were likely unvaccinated!
Lastly, the study doesn’t mention the total number of unvaccinated cases in these 33 outbreaks, so we can’t come to any conclusions about vaccine effectiveness, attack rates, or a person’s relative risk of getting measles.
We can look at some of the larger studies in this meta-analysis to try and figure that out, though!
In the Netherlands study, for example, not one person who was fully vaccinated transmitted measles to another person! And they were less likely to get measles and had fewer complications and hospitalizations.
The Netherlands study makes a great case for getting vaccinated with two doses of MMR!
As does this meta-analysis that Sayer Ji has misrepresented.
“Because measles vaccine failure is rare, only a small proportion of exposed vaccinated people will develop measles (and even a smaller proportion would go on to transmit the virus), thus measles outbreaks are critically driven by unvaccinated cases, including in elimination settings.”
Do vaccinated cases transmit measles? A systematic review and meta-analysis
A study which is a great reminder that those who are vaccinated can rarely get and transmit measles to others.
A study which also reinforces that measles outbreaks are overwhelming driven by those who are unvaccinated, often intentionally unvaccinated.
Who is "Sayer Ji:? Just another guy with a BA in philosophy who has no background in science or medicine profiteering off antivaxxery. https://exposed.substack.com/p/practicing-medicine-without-a-license?r=zrmcb&utm_campaign=post-expanded-share&utm_medium=web