In the wake of the death of Dr. Alister Rodgers from Hendra virus, there have been increasing calls for the Australian government to put significant resources into Hendra virus research. Various areas need to be investigated, including how this virus is maintained in the bat population, how it is transmitted from bats to horses, ways to treat infection and ways to prevent infection. Vaccination is an obvious topic, and creation of a vaccine appears to be possible. However, as I wrote the other day, there’s a question about whether a company would put millions of dollars into development of a Hendra virus vaccine for people, given that the disease is very rare, is currently limited to one region, and only appears to be a risk for people in close contact with sick horses.
One thing that needs to be considered is whether it may be better to develop a vaccine for horses rather than people. Think about it:
- All reported human Hendra virus infections have come from people in close contact with sick horses.
- Human vaccines are very expensive to develop, test, get approved and market.
- Vaccines for animals are much cheaper to make because testing and regulatory requirements are not as strict. (This can lead to marketing of vaccines for animals with limited evidence of effectiveness, but the upside is that vaccines can get to market quicker and with less expense.)
- People are often more willing to get their horses vaccinated than to get vaccinated themselves.
So, even though it might sound strange, development of a Hendra virus vaccine for horses may be a more effective way to protect people.
If this approach is taken, a key step would be continued research into the epidemiology of Hendra virus infection to investigate other routes of human exposure. If people can get infected by other routes, vaccination of horses obviously wouldn’t address the entire problem. However, based on what we know currently, vaccination of horses might be the most effective, timely and economic response to this pressing problem.
This Worms & Germs blog entry was originally posted on equIDblog on 04-Sep-09.