The childhood flu vaccine may also reduce the risk of Strep A infections, according to research by the UK Health Security Agency (UKHSA).
The vaccine, which is given as a nasal spray, is offered to pre-school and primary school children each year.
A new study compared rates of Streptococcus A in areas where all young children were offered the vaccine and other areas where it was rolled out incrementally by year-groups.
Results showed that between 2013 and 2017 rates of Strep A in children aged between two and four years varied from 73.5 per 100,000 in areas where the vaccine was used widely to 93 per 100,000 elsewhere.
The difference was less marked in five-to-10-year-olds, with 57.8 per 100,000 developing Strep A in areas with widespread coverage, compared to 50.3 per 100,000 elsewhere.
However, there was no difference in scarlet fever or serious invasive Group A Streptococcus (iGAS) infection.
Dr Jamie Lopez Bernal, consultant epidemiologist for immunisation and countermeasures at UKHSA, said: “Our findings suggest that the nasal spray vaccine programme, which offers very good protection against flu, may also help contribute to reductions in the rates of (Strep A) infections among children.
“Children who catch influenza are at greater risk from subsequent infections, including Group A Strep, so these findings provide yet more reasons for parents of eligible children to bring them forward for the flu vaccine.
“This is particularly important at this time when we are seeing unusually high rates of Group A Strep infection across the population.”
The UKHSA said it is “not too late” for children to have the flu vaccine.
Parents of pre-schoolers should make an appointment with their GP. Those with older children should contact their school.