underthehedge:jessicalprice:npr:Back in the 1960s, the U.S. started vaccinating kids for measles. As
underthehedge:jessicalprice:npr:Back in the 1960s, the U.S. started vaccinating kids for measles. As expected, children stopped getting measles.But something else happened.Childhood deaths from all infectious diseases plummeted. Even deaths from diseases like pneumonia and diarrhea were cut by half.“So it’s really been a mystery — why do children stop dying at such high rates from all these different infections following introduction of the measles vaccine,” says Michael Mina, a postdoc in biology at Princeton University and a medical student at Emory University.Scientists Crack A 50-Year-Old Mystery About The Measles VaccinePhoto credit: Photofusion/UIG via Getty ImagesUsing computer models, they found that the number of measles cases in these countries predicted the number of deaths from other infections two to three years later.“We found measles predisposes children to all other infectious diseases for up to a few years,” Mina says.And the virus seems to do it in a sneaky way.Like many viruses, measles is known to suppress the immune system for a few weeks after an infection. But previous studies in monkeys have suggested that measles takes this suppression to a whole new level: It erases immune protection to other diseases, Mina says.VACCINATE. YOUR. DAMN. KIDS. I’d read about this afore but didn’t realise it was only really discovered in 2015. It’s a fascinating discovery, especially when you consider that prior to vaccination there were a lot of potentially fatal childhood diseases that you hoped to survive and gain lifelong immunity to…but you might have to try and survive twice if you get measles after them. And lest we forget, measles itself a: can kill and b: is terrifyingly contageous if you look at the R0 for the disease:From this year we’re hopefully all rather familiar with R-numbers now, but for those that aren’t: R number describes how many people (on average) each infected person will go on to infect, i.e. the rate of spread. R=1 means each person infects one new person of their course of the disease keeping the rate of infection stable. So if R is lower than 1, the number of infections goes down, and if R is above 1 the number of infected people will rise. Don’t worry, I’m getting to a point here. Obviously lots of things can alter the R number, e.g. if people take precautions to limit spread or a greater number of people are immune to it the R number goes down, so we can also talk about the R0 or “intrinsic rate of spread”. The R0 is the R number you expect under normal conditions and where no one is immune, and can function as a measure of how contagious a disease is. The R0 for the common cold is like 2-3, seasonal flu varies between 0.9-2.1 (the 1918 pandemic flu was possibly as high as 2.8), COVID-19 is estimated at 3.3-5.7 which is pretty damned high and shows you how it can spread so rapidly through a population if people aren’t careful. Measles is estimated at 12-18. That’s…that’s two to three times higher than the highest estimates for COVID-19, like we’ve all seen how rapidly that can spread. And this level of contagion is why you really fuckin have to keep everyone vaccinated against measles. Because we all know about herd immunity: if enough people are immune then the R0 remains below 1 and transmission peters out quickly. The higher the R0, the higher percentage of the population you have to have vaccinated or otherwise immune to prevent spread. For measles if immunity rates drop below 93-95% herd immunity no longer stops spread and it will rip through the non-immune population. And that’s damned hard because biology isn’t perfect, a small percentage of people vaccinated will, for whatever reasons, not develop immunity, so you actually need to actually vaccinate at an even higher rate than that. That’s why we’ve started seeing measles outbreaks again because with the fact some people cannot get vaccinated and some vaccinations won’t take, it really only takes a very small percentage of people choosing not to vaccinate their kids to let it start spreading again. Tl;dr: Measles is absurdly infectious, and the margin for effective herd immunity is so slim that with people who cannot get vaccinated and the vaccines that don’t take there’s genuinely no room left for people who choose not to so please vaccinate your kids I’m begging you. -- source link