A new study published in the journal Clinical Infectious Diseases (CID) shows that flu vaccination protected children against serious flu illness even when they were infected with a flu virus that was antigenically different from the vaccine virus, the United States Centers for Disease Control and Prevention (CDC) said recently.
The study titled ‘Vaccine Effectiveness Against Life-Threatening Influenza Illness in US Children’, authored by Dr Samantha M. Olson of the CDC’s, National Center for Immunization and Respiratory Diseases reported that that flu vaccination reduced the risk of severe flu in children by 78% against similar flu A viruses and 47% against flu A viruses that had drifted from the vaccine virus.
Further, the vaccine was 76% effective at preventing life-threatening influenza, which included invasive mechanical ventilation, CPR, and other severe complications including death the researchers said.
“This study highlights that flu can cause serious illness in children, but flu vaccines can be lifesaving. This is very good news” CDC Director Dr Rochelle P. Walensky said.
“It’s especially important that children get a flu vaccine in addition to their recommended COVID-19 vaccines this season. Flu season has started and currently, flu vaccination is down in children, so now is the best time to get your child vaccinated if you have not already,” she added.
Flu viruses are constantly changing through a process called antigenic drift, especially H3N2 viruses, which often cause more severe flu, CDC said.
The CDC said that the current study adds to evidence showing that some people who are vaccinated still get sick, but the vaccination can decrease illness severity.
This large CDC study summarises findings from a CDC vaccine effectiveness network that looks at how well flu vaccines work at preventing serious flu illness in children.
“This network is now called the Overcoming COVID19 Network and will investigate how well COVID19 vaccines work to prevent COVID19 hospitalisations in children in addition to how well flu vaccines protect children against flu hospitalisation during 2022,” the CDC added.
Researchers looked at data from the 2019–2020 flu season, during which a record-breaking 199 flu deaths in children were reported to the CDC and when most flu activities were caused by two viruses that were antigenically different from their corresponding vaccine viruses.
During a season when vaccine-mismatched influenza viruses predominated, vaccination was associated with a reduced risk of critical and life-threatening influenza illness in children, the study concluded