By Sharon Atieno
The six-in-one (hexavalent) vaccine protecting against diphtheria, tetanus, pertussis (whooping cough), hepatitis B, Haemophilus influenzae type B (Hib), and poliomyelitis is safe and effective.
According to Niklas Danielsson, Senior Immunization Specialist, UNICEF, the hexavalent vaccine is a combination vaccine of six individual vaccines (antigens) in one. There are no new individual antigens in the new hexavalent combination vaccine.
“All six vaccine components in the hexavalent vaccine have been given to children for many decades, and there is ample strong evidence of the effectiveness and safety of these vaccines,” he said, noting that studies have shown that vaccination with the hexavalent vaccine is as safe and effective as vaccination with the two vaccines, pentavalent and inactivated polio vaccine (IPV), in separate injections.
“As the hexavalent vaccine is being introduced, post-introduction surveillance of adverse events will continue to detect potential very rare side-effects that cannot be detected in trials, as it is done with other new vaccine introductions.”
The World Health Organization (WHO) prequalified the hexavalent vaccine in 2024. The vaccine allows immunization programmes that currently use whole-cell pertussis pentavalent to switch to hexavalent and whole-cell pertussis antigen, to reduce the number of injections in their schedule and to strengthen protection against poliomyelitis.
The hexavalent vaccine has several advantages. First, Danielsson says, the three doses of pentavalent vaccine and two doses of IPV are replaced with three doses of the hexavalent vaccine, thereby reducing the number of injections during a child’s first year of life by two injections.
The switch to the hexavalent vaccine is expected to protect more children against paralytic polio and protect them earlier in life. This is because current coverage with the pentavalent vaccine, which is given at 6, 10 and 14 weeks of age, is often slightly higher, and sometimes substantially higher, than coverage with IPV, often given at 14 weeks and 9 months of age.
He also notes that vaccination with IPV, together with the oral polio vaccine (OPV) drops, is critical for polio virus eradication. At some point, when no wild polio viruses are detected for a certain period, the world will stop vaccinating with OPV and all protection against the recurrence of polio will be from IPV.
“Vaccination with IPV must continue for 10 years after OPV has been stopped and at that point, it becomes programmatically advantageous to have IPV as part of a combination vaccine that all children should receive,” he adds.
Additionally, Danielsson notes, switching from pentavalent plus IPV vaccines to hexavalent vaccine means fewer injections, which reduces the consumption of needles and syringes by the immunization programme.
Further, replacing two vaccines with one and reducing the number of injections means that the number of vaccine vials is reduced in the cold chain. This is an advantage at a time when many programs consider introducing new vaccines that increase demand for cold chain capacity.
He notes that the vaccine is currently readily available. Though there is one producer of a World Health Organization (WHO) pre-qualified hexavalent vaccine with IPV and whole-cell pertussis, at least two more producers are expected to submit documentation for WHO pre-qualification during 2026-2027.
The hexavalent vaccine is available from UNICEF Supply Division and Gavi offers grants to eligible countries to facilitate its introduction. Senegal and Mauritania received their first batch in July.
