By By Elliott Freeman Apr 18, 2012 in Science San Rafael - An investigation by California doctors has revealed that the state's latest outbreak of whooping cough centered around children who had already received the whooping cough vaccine, Reuters reports. After examining the records of juvenile whooping cough patients over an 8-month period, the doctors discovered that 81 percent of patients had received the full series of whooping cough shots, and 11 percent had received only some of the shots. The remaining 8 percent had not received any immunizations for whooping cough. "What was very surprising was After further analysis, Witt and his team surmised that the effectiveness of the vaccine wears off after several years, creating the need for additional inoculations. Unfortunately, drug maker Glaxo Smith Kline (GSK), the manufacturer of the whooping cough vaccine, did not bother to perform long-term studies of its effectiveness. A company spokesperson confirmed this disturbing fact in an email to Reuters, stating that GSK never studied the duration of the vaccine's protection after the shot was given to four- to six-year-olds. Dr. Tom Clark, a medical epidemiologist with the Center for Disease Control (CDC), also provided a troubling analysis of the situation. "It's likely if we move doses around we'd shift the burden of disease, but not necessarily reduce it," he said. However, these explanations alone do not account for the new epidemic of whooping cough in California. According to the In addition, other scientific studies have confirmed a link between vaccines and an increased risk of infectious diseases. In 2009, Revelations like these should be a reminder to parents to do as much research as possible and weigh the risks and benefits before allowing their children to receive vaccines. The study, led by infectious disease specialist Dr. David Witt, was initiated after an unusually large number of whooping cough cases were admitted to Kaiser Permanente Hospital in San Rafael, California in 2010.After examining the records of juvenile whooping cough patients over an 8-month period, the doctors discovered that 81 percent of patients had received the full series of whooping cough shots, and 11 percent had received only some of the shots. The remaining 8 percent had not received any immunizations for whooping cough."What was very surprising was the majority of cases were in fully vaccinated children ," Witt said. "That's what started catching our attention."After further analysis, Witt and his team surmised that the effectiveness of the vaccine wears off after several years, creating the need for additional inoculations.Unfortunately, drug maker Glaxo Smith Kline (GSK), the manufacturer of the whooping cough vaccine, did not bother to perform long-term studies of its effectiveness. A company spokesperson confirmed this disturbing fact in an email to Reuters, stating that GSK never studied the duration of the vaccine's protection after the shot was given to four- to six-year-olds.Dr. Tom Clark, a medical epidemiologist with the Center for Disease Control (CDC), also provided a troubling analysis of the situation. "It's likely if we move doses around we'd shift the burden of disease, but not necessarily reduce it," he said.However, these explanations alone do not account for the new epidemic of whooping cough in California. According to the New York Times , vaccination rates have remained steady as cases of whooping cough have skyrocketed in the state.In addition, other scientific studies have confirmed a link between vaccines and an increased risk of infectious diseases.In 2009, four separate Canadian studies concluded that the seasonal flu shot massively increases the likelihood of contracting the H1N1 flu. According to Science Daily, recipients of the seasonal flu vaccine were up to 250% more likely to be infected by the H1N1 variant than those who did not receive the injection.Revelations like these should be a reminder to parents to do as much research as possible and weigh the risks and benefits before allowing their children to receive vaccines. More about Vaccines, Whooping cough, Immunizations, Center for disease control, Infectious diseases More news from Vaccines Whooping cough Immunizations Center for disease c... Infectious diseases Pertussis