[First Aid Tips] Issue 27 - Do I need to get vaccinated after being bitten by someone?

Yesterday, I went to Guangming Primary School in Lubei District, Tangshan City to teach children about accidental injury prevention. When I was talking about animal bites, I suddenly thought of a question. After being bitten by mammals such as dogs, cats, and wild mice, they all need to be injected with rabies vaccine (abbreviated as rabies vaccine) or rabies immune protein (abbreviated as rabies immune). So, humans are also mammals. Do they need to be vaccinated or immune protein after being bitten by humans? When someone asked me at that time, I suggested that it was more appropriate to give a preventive shot. In the evening, I consulted a lot of literature and summarized it as follows:

1. What is the difference between rabies vaccine or rabies immune protein?

Simply put, rabies vaccine is an antigen, which stimulates the body to produce antibodies for immunity. It is active immunity and takes time to take effect. Rabies immune protein, on the other hand, immunizes by binding to the rabies virus and specifically neutralizing the rabies virus. It is passive immunity and can take effect immediately.

2. Under what circumstances should rabies vaccine and immunization be given?

The case fatality rate of rabies is 100%. There are no contraindications for rabies vaccination after exposure, and it can be administered in any situation, including pregnancy, underlying diseases, etc. Vaccination before the onset of the disease is effective.

For rabies vaccination, the earlier the better, within 24 hours after injury. The dosage should be calculated strictly according to body weight, and a sufficient amount should be injected at one time. Rabies immunoglobulin is calculated at 20 international units per kilogram of body weight (20IU/kg), and anti-rabies serum is calculated at 40 international units per kilogram of body weight (40IU/kg). If the calculated dose is not enough to infiltrate the entire wound, the passive immunization preparation can be appropriately diluted with saline to a sufficient volume for infiltration injection.

If passive immunization agents (rabies vaccine, etc.) are not used on the day of rabies vaccination, passive immunization agents can still be injected within 7 days (including 7 days) after the first rabies vaccination. Passive immunization agents and rabies vaccines should not be injected in the same area; rabies vaccines and passive immunization agents should not be injected with the same syringe.

3. Under what circumstances should you get vaccinated if you are bitten by a dog?

Let's first understand the exposure classification. According to the nature and severity of the exposure, the exposure is divided into three levels. If you are scratched or bitten by a dog, you can first refer to this exposure classification to judge your own situation and then decide whether to get a rabies vaccine.

Image source: Technical Guidelines for Rabies Prevention and Control (2016 Edition)

That is to say, once we are scratched or bitten by a dog, we need to get a rabies vaccine. It should also be noted that the World Health Organization recommends that since the head, face, neck, hands and external genitalia are rich in nerves, as long as the bite occurs in these areas, it is considered a Class III exposure. At this time, in addition to the rabies vaccine, rabies immunoglobulin should also be injected. If we are not sure whether the skin is damaged, we should immediately observe carefully with our eyes after being scratched or bitten by a dog. If it is difficult to judge with the naked eye, you can wipe the surface of the skin with alcohol. If there is pain, it means that the skin is damaged.

4. So what should we do after being bitten by someone?

First, we need to confirm whether the person who bit you is a carrier of rabies. Unless there is clear evidence that the person who bit you is a rabies patient, normal people are not born with rabies. Although human teeth carry germs, after being bitten by a normal person, it is sufficient to disinfect the wound in time to prevent infection .

Secondly, if a person is infected, the mortality rate is close to 00%, and typical rabies symptoms such as "fear of light, fear of water, fear of wind" will appear, which is easy to identify. Only those who are bitten by rabies patients need to be vaccinated against rabies.

Therefore, if normal people are accidentally bitten while playing, they do not need to be vaccinated against rabies.