Smallpox and vaccinia
The Smallpox vaccine, using a similar pox virus called Vaccinia, was always as well as being the first vaccine the most intrinsically dangerous commonly used one. When Voltaire reported that 60% of people caught Smallpox, and there was a 1 in 3 mortality among them, and the previous technique if inducing immunity - variolation - had a mortality on the order of 1-2% the balance of risk was favourable.
Current estimates of death rates in widespread Smallpox immunisation are on the order of 1-2 per million, which requires a significant risk of re-introduction to make favourable except for those tasked to deal with it.
The HIV epidemic has brought renewed interest in developing attenuated poxvirus vectors as future HIV vaccines and perhaps the original smallpox vaccination itself actually protected against HIV.
The history of smallpox and smallpox vaccination is illuminating.
- 1802 - anti-vaccination lobby already established.
- Acts of 1840, 1841 &1853 make vaccination successively universal, free, and finally (until 1948) compulsory.
- 1901-2 London’s last major smallpox outbreak
- Mid-1970s - complications of vaccinia outweigh benefits of vaccination. Vaccination abandoned apart from international travel requirements.
- WHO strategy of surveillance and targeted vaccination
- 1977, Somalia - last naturally occurring case. WHO declare it eradicated in 1980.
- ↑ Esteban M. Attenuated poxvirus vectors MVA and NYVAC as promising vaccine candidates against HIV/AIDS. Human vaccines. 2009 Dec; 5(12):867-71.
- ↑ Weinstein RS, Weinstein MM, Alibek K, Bukrinsky MI, Beda B. Significantly reduced CCR5-tropic HIV-1 replication in vitro in cells from subjects previously immunized with Vaccinia Virus BMC Immunology 2010, 11:23doi:10.1186/1471-2172-11-23