Parents are being urged to get their children jabbed as experts warn outbreaks of serious illnesses could follow the lifting of coronavirus pandemic restrictions.
By a baby's first birthday, they should have received a series of vaccinations to protect them against potentially fatal diseases.
The World Health Organisation recommends 95 percent of babies should get the six-in-one vaccination, which protects against diseases including diptheria, polio and whooping cough, before the age of one to prevent outbreaks.
But Public Health England data shows immunisation rates are below that target in North Lincolnshire where just 91.8 percent of those who turned one between January and March this year had those jabs on time.
That means as many as 33 eligible babies missed their initial immunisations, with the vaccination rate dropping from 95 percent the year before.
Young children should also receive a jab to protect them against measles, mumps and rubella – highly infectious diseases that can spread rapidly – before the age of two.
Figures show there has been a 1.1 percent decrease in the proportion of toddlers receiving their MMR vaccines in North Lincolnshire, with 91.9 percent of those who turned two in the same period vaccinated on time, below the 95 percent target.
While the NHS immunisation programme operated throughout the pandemic PHE statisticians say the introduction of physical distancing measures may have contributed to missed appointments.
And the Royal Society of Public Health says fear of Covid-19 exposure and the “stay at home” message during lockdowns may have deterred parents from taking their children for jabs.
Across England, 91.6 percent of babies in the same cohort received their six-in-one jabs on time, a drop from 92.7 percent over the same period in 2020.
Uptake of the MMR vaccination also dropped slightly nationally from 90.8 percent to 89.3 percent.
The RSPH say it is deeply concerning to see a "persistent decline" in uptake accompanied by a rise in vaccine preventable diseases.
The organisation has called for an investigation into whether disinformation campaigns surrounding the roll-out of Covid-19 vaccines lessened confidence in other immunisation programmes.
Spokeswoman Laura Furness called on the Government to review factors contributing to the fall in uptake and to implement its “long overdue” immunisation strategy.
She said GPs should recall babies who missed vaccines, adding: “The peculiarity of the challenges in accessing health services since March 2020 should not allow us to overlook the fact that the fall in childhood vaccination coverage rates did not begin with the Covid-19 pandemic.
“Remedial action cannot only be left to GP practices and local systems.”
Public Health England said the drop in vaccination levels was concerning and warned of potential disease outbreaks after the lifting of coronavirus restrictions.
Head of immunisation, Dr Mary Ramsay, said: "It is vital that children attend routine vaccination appointments and catch up on any vaccinations they have missed to prevent a resurgence of serious and sometimes life-threatening diseases.”
The organisation is working with the NHS and Government to contact those who have missed vaccines.
A Department of Health and Social Care spokesperson said vaccines were one of the best defences in public health and that the Government was committed to improving uptake.