forget the Zika hysteria.
The really dangerous disease is Yellow Fever, which is spreading in Africa (Angola and now the Congo) and has been made worse by a shortage of vaccines.
How do you protect millions of people from a deadly disease in the space of a few weeks?That has been the challenge after a yellow fever outbreak has killed more than 400 people in Angola and neighbouring Democratic Republic of Congo.
they are so short of vaccine that they are using partial dosages (something we did when Measles vaccine first came out but we lacked enough to protect everyone).
This gives immunity but doesn't last long.
and China has had a few cases in workers who returned from Angola (which is rich in oil, hence the Chinese are there).
so where did the disease come from? This article in the South China Post notes that immigrants from Eritrea were admitted to the country but had fake papers saying they had gotten the immunization, when they did not get it.
These yellow cards used to be important: Proving you had been vaccinated against smallpox, and if you were in certain countries, you had to prove you had gotten your yellow fever shot.
and if they are short of vaccine, it is because massive numbers of people need shots:
Since the outbreak was identified in January, 10.5 million Angolans – 40 per cent of the population – have been vaccinated and the World Health Organisation (WHO) plans to cover the rest of the war-scarred country by the end of the year.
But with a reported case this week of the disease jumping via a mosquito from one person to another in Kinshasa, a city of over 12 million in neighbouring Democratic Republic of Congo, there are concerns about global vaccine supplies running out.
and people from Eritrea are part of the massive influx of "refugees" who are entering Europe.
If I remember correctly, the vaccine is very vulnerable to climate: it has to be kept frozen until used, so I had to travel to a different city designated clinic to get the shot when I was planning to go to Africa....but it usually lasts ten years or more.
so why the problem of making more vaccine? they do it in the old fashioned way, via chicken embryos.
The article also notes that actually more people have died from malaria so far this year than have died from Yellow fever (a different mosquito)
Manufacturers, including the Institut Pasteur, government factories in Brazil and Russia, and French drugmaker Sanofi , use a time-consuming method involving sterile chicken eggs.
CDC page on yellow fever vaccine