- Oct 2020
t’s not clear why the sequence of the vaccines only mattered in girls, partly because there has been very little research into how male and female immune systems are different. “Somehow immunology has been blind to sex,” says Aaby. “If you read research about mortality in low income countries, there is no such thing as boys and girls – there are children. So we perceive that they have to be the same, and they are definitely not the same.”
Take away: "Immune training" or bystander effects from other vaccinations may help to fight off Covid-19 or other infections, in spite of not being specific to that pathogen. Some of these effects are sex-specific.
Claim: "Somehow immunology has been blind to sex"
The evidence: This is not entirely true- there is actually a LOT of research into sex differences in the immune response, and it is well-known that women can generally mount stronger Th1-type immune responses against viral infections than men. This is thought to be partially linked to estrogen cycling, and partly due to the fact that women have 2 active copies of genes associated with immunity because those are encoded on the X chromosomes. Men only have 1 copy, and thus they don't generally mount as strong an inflammatory response. However, women are also more prone to autoimmune diseases as a consequence of having stronger inflammatory responses than men, which is seen in diseases such as multiple sclerosis, rheumatoid arthritis, and lupus.