Rotavirus is a highly contagious virus that primarily causes severe diarrheal illness, especially affecting young children. Before widespread vaccination, almost every child worldwide experienced a rotavirus infection by age five. This commonality often leads to questions about whether an individual can contract rotavirus more than once.
Understanding Rotavirus
Rotavirus is a viral infection that targets the stomach and intestines, leading to gastroenteritis. It spreads predominantly through the fecal-oral route, transmitted when microscopic particles of stool from an infected person are ingested, often through contaminated hands, surfaces, food, or water. The virus is highly stable in the environment and can survive on surfaces for days or even weeks.
Symptoms typically appear within two to three days after exposure and can include severe watery diarrhea, vomiting, fever, and abdominal pain. These symptoms can last for about three to eight days. For infants and young children, the significant fluid loss from vomiting and diarrhea can rapidly lead to dehydration, which can be a serious complication.
Immunity Following Infection
A natural rotavirus infection prompts the body to develop an immune response. This initial exposure typically provides some level of protection against future infections. The immune system generates antibodies, particularly against the viral proteins VP4 and VP7 located on the virus’s outer shell, which are important for immunity.
While the first infection often leads to the most severe symptoms, subsequent infections are generally less severe or even asymptomatic. This reduced severity is due to the partial immunity acquired from previous encounters. However, this natural immunity is often not complete or fully protective against all strains.
Possibility of Multiple Infections
It is possible to get rotavirus more than once. The primary reason is the existence of multiple rotavirus strains, or genotypes. Immunity developed against one strain may not fully protect against another, similar to how different types of flu viruses circulate. Globally, common rotavirus strains like G1P, G2P, G3P, and G9P account for most cases.
Immunity gained from a first infection might not be complete or robust, especially in very young children or those with weakened immune systems. Immunity can also wane over time, increasing susceptibility to re-infection. These subsequent infections are typically milder, shorter in duration, or might even be asymptomatic, as the immune system is better prepared to fight off the virus. While severe re-infections are less common, they can still occur if the individual encounters a significantly different strain or has compromised immunity.
Vaccination’s Role
Rotavirus vaccines prevent severe rotavirus disease and its complications. They are effective in protecting against the most severe outcomes, including hospitalization. For instance, rotavirus vaccines offer 85% to 98% protection against severe illness and hospitalization in infants.
Vaccination reduces the risk of severe disease, though it does not guarantee complete protection against all rotavirus infections. Vaccinated children may still experience mild infections, but these cases are less severe than in unvaccinated individuals. Widespread use of rotavirus vaccines also contributes to herd immunity, indirectly protecting unvaccinated individuals by reducing overall virus circulation.