Pertussis (or whooping cough) has increased in prevalence in the United States over the last several years, and can be fatal for infants. Infants are too young to receive immunization with pertussis vaccines, so prevention must occur via relatives, who are the most common source of pertussis in infants. (Parents are the source of 55 percent of cases, while other relatives, including grandparents, are the source of most remaining cases.)
While relatively effective vaccines (known as tetanus-diphtheria-accellular pertussis, or Tdap) were developed in 2005, these were not sufficiently tested among older adults to determine whether they were as safe as existing non–pertussis vaccines in use by older adults. A recent study reports on the safety of Tdap vaccines on adults age 65 or older, which is significant not only for infant health but for grandparents and older adults who provide childcare for their families.
The study compared over 100,000 adults age 65 and over who received the Tdap vaccine with a matched sample of older adults receiving a tetanus and diphtheria (Td) vaccine that is used in standard preventive practice for older adults. When comparing the rates of adverse events to both vaccines (swelling or other allergic reaction at the site of injection was the most common), the researchers found no higher risk in the Tdap vaccine than the Td vaccine. They also found that older adults had no higher rates of adverse reactions to Tdap than younger populations.