Vaccination or Immunization has proved to be a very important and effective preventive strategy to prevent disease, disability, and death from many serious infections. Rotavirus vaccines offer valuable protection from the medical problems caused by that virus, and WHO has advised a world-wide rotavirus vaccination since 2009.
These vaccines have become a part of national immunization programs of more than 100 countries. Although there are many countries where these vaccines are still not included in national immunization programs, the situation is changing for the better.
This Guide to Rotavirus vaccines will be useful for parents to know the specifics and clear the myths and misconceptions.
What is Rotavirus and why is it dangerous?
Rotavirus is an RNA-virus belonging to retroviridae family. It was named Rota (meaning Wheel in Latin) because of its wheel-like appearance under electron microscope.
It is the leading cause of diarrhea in children under the age of five years. It can be severe, and even lead to death. It is also, highly infectious, passing easily from person to person.
How does Rotavirus infection transmit?
Rotavirus infection has a short incubation period (time from exposure to symptoms) of less than 48 hours. It passes through Fecal-Oral route, through infected person’s stools either through direct contact or fomites (contaminated objects and surfaces).
Transmission through contaminated food or water is uncommon.
What are the clinical features of Rotavirus infection?
In babies and children under 5 years, apart from many asymptomatic or self-limited watery diarrhea cases, there can be symptoms such as high-grade fever (in one third patients), severe diarrhea, vomiting and abdominal pain. These gastrointestinal symptoms usually last 3-7 days.
Complications such as dehydration, electrolyte imbalance, metabolic acidosis and even death may happen in such severe cases.
First infection after 3 months of age is usually severe, whereas in babies less than 3 months, the disease is usually mild because of protection offered by breastfeeding and the antibodies passed on from the mother.
In immunocompromised children, the disease may become severe or persistent.
In adults and older children, the infection may be asymptomatic or cause mild diarrhea.
How is Rotavirus infection diagnosed?
Clinical features do not differentiate rotavirus gastroenteritis from other infectious gastroenteritis. Using the patient’s stool sample, there are test kits to detect rotavirus antigen through ELISA (Enzyme Linked Immuno-Sorbent Assay) technique or to detect nucleic acid through PCR (Polymerase Chain Reaction). The other sophisticated methods such as electron microscopy or viral culture are available only in few high end facilities.
What is the treatment of rotavirus infection?
There is no specific medicine to cure rotavirus infection. This infection is treated symptomatically with antipyretics for fever, and Oral Rehydration Solution or intravenous fluids for rehydration.
How common is Rotavirus infection?
According to WHO, every year there are 25 million outpatient visits and 2 million hospitalizations due to rotavirus infections. Severe rotavirus gastroenteritis cases are usually seen in 6-24 months age-group.
According to a JAMA Pediatrics research article, in 2016, Rotavirus infection globally led to 258 million diarrhea cases and 128000 deaths in children less than 5 years. Approximately half of these deaths occurred in just 4 countries- India, Pakistan, Nigeria, and Democratic Republic of Congo.
How do rotavirus vaccines protect against its infection?
Presently available rotavirus vaccines are given as oral drops. They are live attenuated vaccines, meaning they contain a weakened form of rotavirus, which introduces mild infection in the body, and stimulates the immune system to produce protective antibodies.
What are the most used rotavirus vaccines?
There are two main types of rotavirus vaccines in use- RotaTeq by Merck and Rotarix by Glaxo-Smith-Kline.
Rotateq (RV5) is developed from 5 human and bovine rotavirus parent strains, and Rotarix (RV1) from 1 specific human rotavirus parent strain.
What is the recommended rotavirus vaccine schedule?
3 doses given at minimum 4 weeks interval.
First dose before 15 weeks. (Earliest by 6 weeks)
Last dose before 32 weeks.
Most commonly given at 2-, 4- and 6 months vaccination visits, along with other main vaccines.
2 doses given at minimum 4 weeks interval.
First dose latest before 15 weeks (Earliest by 6 weeks)
Second dose latest before 24 weeks.
Most commonly given at 2- and 4 months vaccination visits, along with other main vaccines.
How effective are these vaccines?
Rotateq (RV5) is in use since 2006 and Rotarix since 2008; and both are found to be quite effective against rotavirus infections.
Most children (about 9 out of 10) who get the vaccine will be protected from severe rotavirus disease. About 7 out of 10 children will be protected from rotavirus disease of any severity.
Vaccination also reduces the number of emergency visits, hospitalizations, and mortality.
The overall protection lasts for several years.
What are the side-effects of the rotavirus vaccines?
Most children experience no significant side-effects after rotavirus vaccines.
With RotaTeq, approx. 10% recipients may have diarrhea or vomiting. There may be greater chances of otitis media, nasopharyngitis or bronchospasm (wheezing).
With Rotarix, approx.10% recipients may experience irritability, and few may have cough, cold or flatulence.
With both vaccines, there is a slightly increased risk of intussusception (a type of intestinal obstruction where one part of intestine telescopes into the other).
What are the contraindications and precautions against these vaccines?
Severe reaction to the past dose of rotavirus, severe immunodeficiency and history of intussusception are the contraindications to rotavirus vaccines. Severe latex allergy is a contraindication for Rotarix vaccine as it is administered with latex-based applicator.
Any moderate or severe acute illness, chronic gastrointestinal diseases or altered immune status should be looked at as precautions.
What are the newer rotavirus vaccines?
There are many newer rotavirus vaccines that are already being used in certain countries.
Rotavac and Rotasiil vaccines are developed and being used in India; Rotavin is developed and being used in Vietnam, and Lanzhou Lamb Rotavirus vaccine is developed and being used in China. All these are oral vaccines.
Rotavac and Rotasiil are given in 3 doses at 6, 10 and 14 weeks; Rotavin is given in 2 doses at 2 and 4 months; and Lanzhou vaccine is given annually once to children from 2 months to 3 years of age.
Apart from these, there are multiple oral and injectable vaccines, which are currently in various stages of development.
- Rotavirus is the leading global cause of diarrhea or gastroenteritis in children under the age of 5 years.
- It affects millions of children and leads to thousands of deaths across the globe.
- There is no specific treatment or cure for rotavirus infection.
- Rotavirus vaccines offer a safe and effective prevention against this potentially deadly infection.