Covaxis (also licensed as
Triaxis or
Adacel in individual countries) is a combined
tetanus toxoid, reduced
diphtheria toxoid, five component acellular
pertussis (namely detoxified
pertussis toxin, filamentous
hemagglutinin,
pertactin, and fimbriae types 2 and 3)
vaccine for the prevention of
diphtheria,
tetanus, and
pertussis. It is approved for use in Europe as a single intramuscular booster dose in children (aged ≥ 4 years), adolescents, and adults, and in the US it is approved for use in individuals aged 11-64 years. In large, randomized, controlled clinical trials conducted in the UK and North America, a single intramuscular booster dose of
Covaxis induced robust immune responses for all of its component
antigens when given to children (aged ≥ 4 years), adolescents, and adults. In addition,
Covaxis vaccine was safe and generally well tolerated in terms of solicited and unsolicited local injection-site and systemic adverse events, most of which were of mild intensity and resolved without sequelae. Furthermore, the immunogenicity of each individual component and the reactogenicity of
Covaxis vaccine in children, adolescents, and adults was generally similar to that of comparator
vaccines. Despite being a
vaccine-preventable disease and having >90% primary vaccination coverage worldwide,
pertussis remains uncontrolled, particularly amongst adolescents and adults. Given the changing epidemiology of
pertussis and the requirement to reduce
infection in adolescents and adults (including healthcare workers) and thereby prevent transmission of the disease from these individuals to very young infants, the new 'cocoon strategy' recommended in current vaccination guidelines has become a key strategy in the management of morbidity and mortality associated with
pertussis. This strategy focuses on the immunization of healthcare workers, and the parents and family members of infants who are too young to have undergone primary immunization, so as to prevent the transmission of
pertussis to these young at-risk infants. The implementation of the 'cocoon strategy' may finally give countries the ability to control
pertussis infections in these at-risk infants and ultimately provide the desired herd immunity against
pertussis. In line with this strategy, a booster dose of
Covaxis vaccine provides a valuable option to reduce
pertussis morbidity and mortality, and to maintain seroprotection against
diphtheria and
tetanus in children (aged ≥ 4 years), adolescents, and adults.