Why Don’t We Have Vaccines Against Everything?
Money is just the obvious obstacle. A few diseases, like H.I.V., so far have outwitted both the immune system and scientists.
Vaccines are among the most ingenious of inventions, and among the most maddening.
Some global killers, like smallpox and polio, have been totally or nearly eradicated by products made with methods dating back to Louis Pasteur. Others, like malaria and H.I.V., utterly frustrate scientists to this day, despite astonishing new weapons like gene-editing.
We have a vaccine for Ebola that protects nearly 100 percent of its recipients, but we are lucky to get a routine flu shot that works half that well.
We have children’s vaccines against measles, mumps, rubella, diphtheria, whooping cough, tetanus, chickenpox, polio, hepatitis A and B, rotavirus, pneumococcus, haemophilus influenzae and meningococcal disease.
They have changed our expectations of mortality — and of parenthood. In 17th century England, one-third of all children died before age 15. Today, thanks largely to those vaccines, less than 1 percent of English children do.
In tropical countries, there are vaccines against yellow fever, cholera, Japanese encephalitis, meningitis A, typhoid, dengue and rabies. But there is still — despite 30 years of effort — no AIDS vaccine.
There is no universal flu vaccine. There are no vaccines with long-lasting protection against malaria or tuberculosis.
None for parasites like Chagas, elephantiasis, hookworm or liver flukes. None for some viral threats that could become pandemic, like Nipah, Lassa and Middle East Respiratory Syndrome.
None for some that already have, including Lyme, West Nile, Zika and hepatitis C.
None for respiratory syncytial virus, which kills infants, nor even for the dozens of causes of common colds.
Vaccines are among the world’s greatest medical advances, like clean water, soap, bleach, sewage systems and antibiotics. In a rational world — one where budgets are built on lives saved per dollar — spending on vaccine research would rival that on defense research.