An international team has created a new model, using Nigeria as a case study, that could help speed up the implementation of rubella vaccination in countries that haven’t done so yet. Public health officials have to consider the benefits and risks of infectious diseases spreading across the country when making vaccination policies. However, these decisions are usually based on national-level data and may not take into account local differences in some countries. The new analysis, conducted by an international team that includes PenResearchers from a state university found that the recommendations resulting from their study could prevent some countries from reaping the benefits of vaccination and eliminating diseases like rubella on a global scale. Rubella is a contagious viral infection that typically causes mild symptoms in children. The team focused on Nigeria, one of 19 countries that has not yet implemented rubella vaccination, as a case study. Their research was published in the journal Vaccine.
According to senior author Matthew Ferrari, who is a biology professor and director of the research team, rubella is relatively mild if contracted during childhood but poses a high risk if contracted as an adult.or of the Center for Infectious Disease Dynamics at the Huck Institutes of Life Sciences at Penn State. “The policy surrounding rubella vaccination has been focused on the risk in adults, which has hindered the benefits of rubella vaccination in some countries.”
One of the main concerns for adults is the potential risk of congenital rubella syndrome (CRS), a serious health condition that can occur if a pregnant individual becomes infected with the virus. When an infectious disease like rubella is widespread, individuals are more likely to contract it at a younger age. Additionally, because the rubella virus provides immunity, those who are infected as children w rnrnthat they have controlled rubella transmission before considering stopping the vaccine. This is done through a combination of routine immunization, effective surveillance, and monitoring the incidence of rubella and CRS. In addition, efforts to vaccinate women of childbearing age who are susceptible to rubella are also important in preventing CRS. The ultimate goal is to eliminate rubella and CRS altogether, but achieving this requires a comprehensive and sustained strategy.The goal is to achieve a coverage level of 80% or higher, either through routine immunization or supplemental campaigns, before introducing rubella vaccination. It has been commonly believed that when vaccination coverage exceeds this threshold, the decreased risk of CRS from less rubella virus outweighs the paradoxical increase in CRS risk because infections tend to occur later in life, according to Ferrari.
In collaboration with the U.S. Centers for Disease Control and Prevention and the Nigeria Center for Disease Control and Prevention, the research team examined the epidemiology of rubella in Nigeria. Rubella is a comparativelyrisky CRS. The rarity of the disease makes it challenging to measure the potential harm and risk of CRS. Additionally, the assessments are complicated by Nigeria’s wide disparities in wealth, vaccination coverage, healthcare access, and birth rates, all of which contribute to the risk of infection and CRS. To better understand these factors, the team examined data from a nationally representative serosurvey that identifies the presence of antibodies in the blood. This data provided insight into the number of people, especially women of reproductive age, who had rubella antibodies and were at potential risk for CRS.The researchers examined the risk of rubella infection and its geographical variations. They found that the northern part of the country had twice the transmission rate compared to the south. They also estimated the number of pregnancies that could be affected by rubella infection today.
“We based our findings on solid empirical data and real-world observations,” Ferrari stated. “Some parts of the country are already able to vaccinate more than 80% of children based on their current measles vaccination rate, but there are still low vaccination rates in others.”Vaccination coverage in the northern part of the country is currently a barrier to nationwide introduction under the current recommendation. Additionally, the concern about increased cases of Congenital Rubella Syndrome (CRS) may not be as severe as previously thought, according to Ferrari. The team’s new estimates of transmission rates suggest that the 80% threshold is conservative, and implementing a rubella vaccination program in Nigeria today could potentially reduce the number of CRS cases by thousands in the first five years. Although some states may see an increase in CRS risk by hundreds of cases, this increased risk would not materialize until 10 years later.It is important for public health officials to create and implement policies and programs to prevent the spread of rubella.
“Improving routine immunization programs around the world will benefit everyone. By doing this, we can completely eliminate the rubella virus from the planet,” Ferrari stated.
Â
