Frozen vaccines & helpful helminths

Frozen vaccines
Hepatitis B causes jaundice and liver infections, and if you are unlucky, it can kill you. Luckily, there’s a vaccine for it. If you’re planning a holiday in Africa or Asia, you can get a jab from the Municipal Health Service, the GGD. All they have to do at the GGD is reach into the fridge - no problems here, but in countries where hepatitis B is common, it’s not always easy to store the vaccines in a cool place. A group of pharmacologists from Groningen and Leiden researcher Gideon Kersten tried freeze-drying the vaccines and published a report of their attempts in the European Journal of Pharmaceutical Sciences. The trick is not just to freeze-dry the vaccines: you need to add some sugar before doing so. The sugar stabilises the proteins in the vaccines, which would otherwise separate. Adding sugar gives the vaccines a longer shelf-life than fluid vaccines have, even at higher temperatures. That’s good news, but the most important question is whether the vaccine still works after being freeze-dried and stored. The answer is it does in mice, at least. In fact: it works even more effectively. And that just may be very good news in the long term, even for people in countries where fridges work.

A sort of vacuum cleaner has been installed on the roof of the Leiden University Medical Centre to extract pollen from the air. A biologist then counts the pollen grains, determines the variety and that information is published on sites like This method has a couple of disadvantages: it must be done manually and even experts can’t always distinguish between related species just on the basis of their pollen grains. In the science journal Molecular Ecology Resources, researchers from the LUMC headed by geneticist Ken Kraaijeveld describe a different method. In brief, it means collecting the grains, extracting the DNA and determining the species of the plants from the DNA in their pollen.
This process can largely be automated, in which case, pollen counts could be done in all sorts of places in the Netherlands. According to the authors, another advantage is that you can expand the vacuum-cleaner method to count bacteria and fungi spore relatively easily.

Health experts across the globe are seeing a rise in the number of people with allergies. A possible explanation for the increase is the hygiene hypothesis: our environment is supposedly so clean our immune systems, having few challenges to cope with, do not learn properly when and how to respond. Worms seem to have an important part in this; the less exposure to parasitic worms, the more our immune systems lash out, causing more asthma and other illnesses. Or so it seems. In Pediatric Allergy and Immunology, Abena Amoah, a parasitologist, has collected all the research from recent years, revealing that, in practice, the hypothesis is difficult to prove. Though some studies show a clear, inverse relationship between the number of worms and frequency of the allergy, that is not the case in many studies. It is also not known whether treating a patient for worms will aid or obstruct the development of oversensitive reactions. It would be ideal if we could use the substances from the worms in a pill that could prevent allergic reactions without having a real worm infection. Clinical research with human volunteers is already underway, according to Amoah and her co-authors.

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