Rabies is a viral disease that affects the central nervous system and is almost always fatal once symptoms appear. Rabies can be transmitted to humans through bites or scratches from infected animals, most commonly dogs. Rabies causes tens of thousands of deaths worldwide every year, but is preventable through vaccination. So why don’t more people get vaccinated against rabies?
There are several reasons why rabies vaccination rates remain low, especially in developing countries where rabies is endemic:
- Lack of awareness – Many people are simply unaware of the risks of rabies and the importance of vaccination for prevention.
- Cost – Human rabies vaccines can be prohibitively expensive, ranging from $100-$1,000 for the full post-exposure prophylaxis, which is out of reach for people in poorer countries.
- Availability – Rabies vaccines may not be widely available in rural or remote areas where they are needed most.
- Complacency – In areas where human rabies cases are rare, there tends to be complacency around the importance of vaccination.
Improving access to affordable rabies vaccines and increasing public awareness about rabies risks and prevention are key strategies for increasing vaccination rates globally.
What is rabies and how do humans get it?
Rabies is caused by the rabies virus, which spreads through the bites or scratches of infected animals. The rabies virus is present in the animal’s saliva and gets introduced into the human body through broken skin.
In up to 99% of cases, domestic dogs are responsible for transmitting rabies to humans. However, rabies can also be spread by wild animals like bats, foxes, raccoons, and skunks.
Once the rabies virus enters the body, it travels along the neural pathways to the brain. The incubation period can be anywhere from a few days to several years, but is typically 1-3 months.
During the incubation period, the person infected shows no symptoms. But once clinical symptoms appear, the disease is almost always fatal.
Early symptoms of rabies include fever, headache, and general weakness. As the disease progresses, neurological symptoms arise like anxiety, confusion, agitation, hallucinations, and insomnia.
The disease ultimately leads to paralysis, coma, and death once neurological symptoms start. There is no cure for rabies once symptoms begin, but it can be prevented through vaccines given before or immediately after exposure.
What is the rabies vaccine and how does it work?
The rabies vaccine works by inducing active immunity against the rabies virus. There are several types of rabies vaccines available:
- Human diploid cell vaccine (HDCV) – Made using human cell cultures
- Purified chick embryo cell vaccine (PCECV) – Made using chick embryo fibroblasts
- Rabies vaccine adsorbed (RVA) – Made using chicken embryo cells
- Rabies vaccine absorbed (RAB) – Made using fetal rhesus lung cells
These vaccines contain inactivated or weakened forms of the rabies virus. When administered, they stimulate the immune system to produce antibodies against the rabies virus. The antibodies neutralize the virus if exposure occurs later.
The rabies vaccine is given through a course of injections – either before potential exposure to rabies (pre-exposure prophylaxis) or after suspected exposure (post-exposure prophylaxis).
Pre-exposure prophylaxis involves simpler and fewer doses, while post-exposure prophylaxis involves more injections given over 28 days. Prompt vaccination after exposure almost always prevents the fatal disease.
What does the rabies vaccine schedule look like?
The rabies vaccination schedule depends on whether it is being given as pre-exposure or post-exposure prophylaxis.
Pre-exposure prophylaxis schedule:
- 3 doses given over 28 days on days 0, 7, and 21 or 28
- Booster doses recommended every 2 years if continual risk of exposure
This simpler pre-exposure schedule primes the immune system and makes post-exposure treatment easier if needed later.
Post-exposure prophylaxis schedule:
- Rabies immune globulin (antibodies) injected on day 0
- 5 doses of rabies vaccine given on days 0, 3, 7, 14, and 28
This post-exposure schedule must begin immediately after suspected rabies exposure, and involves more time, doses, and expense compared to pre-exposure prophylaxis. But it can still prevent development of rabies if administered promptly.
What are the side effects of the rabies vaccine?
The rabies vaccine is very safe and serious adverse reactions are rare. Mild side effects can sometimes occur and may include:
- Soreness, redness or swelling at injection site
- Headache
- Fever
- Fatigue
- Chills
- Stomach pains
- Nausea or vomiting
These mild reactions typically resolve within a few days. Serious allergic reactions are possible but very uncommon, occurring in less than 1 in 1 million vaccinated individuals.
Overall, the rabies vaccine is extremely low risk compared to the near 100% fatality rate of rabies infection once symptoms start. Getting vaccinated is always safer than going unvaccinated if exposure occurs.
Who should get the rabies vaccine?
The following groups are recommended to receive rabies vaccination:
- Veterinarians and animal handlers – Have frequent contact with animals that may harbor rabies virus
- Laboratory workers – Handle samples that may contain live rabies virus
- Travelers – Those spending over a month in countries with endemic rabies should get pre-exposure prophylaxis
- Children – More likely to suffer bites and scratches while playing with animals
- Post-exposure – Anyone potentially exposed to rabies virus from a bite or scratch should receive prompt vaccination
Pre-exposure vaccination is ideal for those at continual risk of rabies exposure. Post-exposure prophylaxis can prevent rabies after recent exposure. Discuss the need for rabies vaccination with your healthcare provider if you may be at risk.
Why don’t more humans get the rabies vaccine?
Despite the prevalence and lethality of rabies virus, rabies vaccination rates remain lower than optimal globally. There are several barriers to wider vaccination uptake:
Cost:
- Full post-exposure prophylaxis costs $1,000-$3,000 in the U.S. and is often out of reach in lower income countries
- Pre-exposure vaccine course costs $300-$800
- Prices limit access to rabies vaccines across much of the world
Availability:
- Rabies vaccines may not be carried or routinely administered at many clinics and doctors offices
- Access to rabies vaccines is more limited in rural or underdeveloped areas
- Vaccine shortages can occur if outbreaks deplete supplies
Awareness:
- In countries where human rabies is rare, awareness of risk drops
- People may not realize rabies exposure warrants urgent medical attention
- Misconceptions about rabies can impact perception of vaccination need
Complacency:
- Individuals underestimate real risks of rabies in their area or for their occupation
- People avoid shots or vaccines in general due to dislike of injections
- Authorities don’t prioritize rabies vaccination campaigns without ongoing outbreaks
Overcoming these barriers requires increased education, access, and affordability of rabies vaccines across the globe.
What efforts are being made to increase rabies vaccination rates?
International efforts are ongoing to reduce rabies deaths globally through improved vaccination, including:
- Gavi, the Vaccine Alliance has prioritized improving availability and affordability of rabies vaccines in poor countries
- WHO, OIE, and other agencies have launched rabies elimination pilot programs in Asia and Africa
- Mass dog vaccination campaigns aim to control rabies at the animal source
- Introduction of intradermal vaccine delivery requires smaller doses, reducing cost
- Training programs improve ability of health workers to promptly administer vaccines
- School-based and community outreach improves public knowledge
However, far more remains to be done to make rabies vaccines universally accessible and promoted. An estimated 59,000 people still die from rabies every year, mostly in Africa and Asia where canine rabies is endemic. Expanding rabies vaccination coverage remains an urgent public health need to prevent unnecessary rabies deaths.
How can individuals reduce their rabies risk?
While the most effective rabies prevention is vaccination, some other tips for reducing your risk include:
- Avoid handling unknown animals, especially dogs, cats, bats and wildlife
- Seek prompt medical care for any animal bite to rapidly assess rabies risk
- Follow up with animal control to test any domestic animal that has possibly exposed someone
- Educate children to avoid petting or feeding unfamiliar animals
- Keep vaccinations of pets and livestock up to date
- Report any incidence of animals acting strangely or foaming at the mouth
If you live in or travel to an area where rabies is common, speak to your doctor about pre-exposure vaccination if your occupation or activities place you at increased risk. Stay alert for any potential exposures. And if bitten or exposed, immediately seek treatment – post-exposure vaccines can still prevent rabies if given soon after transmission.
Conclusion
Rabies remains a significant yet preventable public health threat, responsible for tens of thousands of deaths annually. Safe and effective rabies vaccines have been available for decades, but are prohibitively expensive and inaccessible for many of the world’s poorest regions. Increasing administration of rabies vaccines requires addressing economic and awareness barriers on a global scale. But vaccination continues to be the most crucial method for eliminating this invariably fatal disease. Wider vaccination coverage combined with public education could make human rabies a thing of the past.