CVD 103-HgR is currently the only vaccine approved by the US FDA to prevent cholera . Recently, the CDC Advisory Committee on Immunization Practice (ACIP) of the United States issued a recommendation for the cholera vaccine .
What is cholera?
cholera is an acute watery diarrhea disease caused by toxic Vibrio cholerae (V. cholerae), including the more common O1 serotype and the rare O139 serotype. Human cholera infection mainly involves contaminated water or food through , and can also be transmitted directly through fecal oral, but there are fewer secondary cases of human-to-human transmission. The incubation period of cholera usually ranges from several hours to several days.
Toxic Vibrio cholerae O1 type can cause a series of symptoms. Up to 10% of the infections show severe and large amounts of watery diarrhea. If treatment is not done in time, patients with can experience severe dehydration and death within a few hours. The mortality rate without rehydration treatment can be as high as 50%, while it can be reduced to 1% after rehydration treatment.
There are 50 countries around the world that belong to endemic cholera disease areas, which can lead to large-scale epidemics. The cholera epidemic is associated with unsafe water and inappropriate sanitation facilities. It is estimated that 1.3 million to 4 million cholera cases and 210,000 to 1.43 million cholera deaths occur every year worldwide.
How to prevent cholera?
Maintain hygiene and avoiding intake of unclean food and water is an important means to prevent cholera. In addition, it is necessary to pay attention to people with the following risk factors. It is more likely to cause serious symptoms after infection with Vibrio cholerae .
risk factors for severe cholera includes:
- high dose exposure;
- in the stomach pH value elevated (people who use antacids, proton pump inhibition therapy or partial gastrectomy );
- O blood ;
- pregnancy.
CVD 103-HgR is a single-dose oral live attenuated cholera vaccine, and it is currently the only cholera vaccine approved for use in the United States. In June 2016, the U.S. FDA approved CVD 103-HgR for the prevention of Vibrio cholerae O1 in adults aged 18-64; it expanded to children and adolescents aged 2-17 in December 2020.
Protective effects of cholera vaccine can usually last for at least a few years , O-specific polysaccharide-specific memory B cells are also associated with long-term protection, but are more difficult to measure than serum antibody .
ACIP recommendations for preventing cholera
❖Personal protection measures
All travelers who go to cholera epidemic areas should eat safe food and water and wash their hands frequently with soap and safe water.
❖Popular populations for vaccination with CVD 103-HgR vaccine
ACIP recommended
travelers aged 2-64 who go to active cholera transmission areas to receive CVD 103-HgR. An active cholera transmission area is defined as a province, state or other administrative region within a country. Endogenous or epidemic cholera caused by toxic Vibrio cholera O1, including areas where cholera activity has occurred in the past year, which are prone to recurrence of cholera epidemics. Areas of active cholera transmission do not include areas where only rare imported or sporadic cases have been reported.
CDC cdc :
- Africa: Benin , Cameroon , DRC , Ethiopia , Kenya , Malawi , Mozambique , Niger , Niger , Niger , Niger , Niger , Somali , South Sudan , Tanzania , Uganda , Zambia
- Asia: Afghanistan , Bangladesh , India, Iraq , Nepal , Pakistan , Philippines , Syria , Herman
- Herman America: Haitian
❖CVD 103-HgR boosts immunity
Currently, data on the safety or effectiveness of CVD 103-HgR boosts immunity prevention of cholera. ACIP There is no recommendation for boosting immunity .
❖How to inoculate CVD 103-HgR
Go to an area where cholera spread is active before traveling to an area where ≥10 days before
, and take oral CVD 103-HgR. Food or beverages should be avoided within 60 minutes before and after vaccination .
htmlThe medication instructions for people aged 12-5 and 6-64 are different. Dissolve CVD 103-HgR in 100 mL of pure water (refrigerated or room temperature, non-carbonated, bottled water or spring water without flavoring). Tap water cannot be used (because tap water contains chlorine, it will affect the viability of live attenuated vaccines). People aged 6-64 years old dissolved all CVD 103-HgR in all (100 mL) redissolution buffer solution; while children aged
indicates that CVD 103-HgR should not be mixed with food and beverages (such as rice porridge, applesauce , apple juice or milk) (because there is too much foam) and should not be mixed with drug flavorings containing propylene glycol (because propylene glycol has a bactericidal effect). Data support can mix the vaccine with sucrose (1-4 grams or 1 teaspoon) or stevia sweetener (1 grams or 1 pack) , although this is not specified in the instructions.
❖Other drugs or vaccines and CVD 103-HgR
antibiotic
: The use of antibiotics before and after oral vaccines may reduce the effectiveness of the vaccine, but the degree of impact depends on the antibiotic half-life , range of action, etc.; the optimal use interval between CVD 103-HgR and antibiotics is unknown, and the instruction manual stipulates that should not be used before and after vaccination.
Antimalarial drugs: chloroquine may weaken the immune response to CVD 103-HgR. It is recommended that people taking chloroquine need to take CVD 103-HgR after ≥10 days. Doxycycline can also be used to prevent malaria , but the optimal interval between CVD 103-HgR and doxycycline is unknown.
Other vaccines: There is currently no data on the simultaneous administration of CVD 103-HgR with other vaccines (such as the enteric-coated oral attenuated live typhoid vaccine Ty21a). ACIP experts assume that CVD 103-HgR buffer may interfere with Ty21a preparations. It is recommended that the first dose of Ty21a can be taken after ≥8 hours after ingestion of CVD 103-HgR, to reduce potential interference.
❖ Contraindications and other precautions
Contraindications: for people who are allergic to any ingredient of CVD 103-HgR or any cholera vaccine. In addition, there is no data on CVD 103-HgR that lacks data on people with less than 2 years of age or ≥65 years of pregnancy or lactating , and immune function deficits. For most people with altered immunity, ACIP usually does not recommend live vaccination.
shedding and spreading: CVD 103-HgR is an attenuated oral live vaccine. After vaccination, can be excreted from the body through feces, which can last for ≥7 days and may be transmitted to close contacts of .It is recommended to wash your hands after going to the toilet. Caregivers should also pay attention to hand hygiene when changing the lining for vaccinated people.
