States with low Covid-19 vaccination rates also saw low rates of flu vaccinations in 2021, according to a study published in the New England Journal of Medicine, suggesting that beliefs about Covid-19 vaccines affected how people felt about flu vaccines.
For the study, researchers looked at CDC data on both Covid-19 and flu vaccine uptake through January 2022.
During the first year of the pandemic, the researchers found that flu vaccination rates held fairly steady compared with previous years. However, during the second year of the pandemic when Covid-19 vaccines became available and were being promoted, flu vaccination rates dropped 4.5 percentage points in states that saw below-average Covid-19 vaccination rates.
There was also a positive effect among states with high Covid-19 vaccination rates, as those states saw a 3.8 percentage point increase of flu vaccination rates.
Vaccination rates for both shots varied significantly, with Covid-19 vaccination rates ranging from 50% in Alabama to 81% in Rhode Island and flu vaccination rates ranging from 31% in Mississippi to 59% in Connecticut.
In all, the researchers estimated that a state's Covid-19 vaccination rate could predict 60% of its flu vaccination rate.
The researchers concluded that "[t]he polarizing nature of vaccination against coronavirus disease 2019 (Covid-19) within the United States threatens public health and has contributed to variable statewide vaccine uptake that ranged from 50 to 80% as of January 2022."
The researchers wrote that the effects of Covid-19 vaccination on flu vaccination could be explained by "belief generalization," with those who supported or opposed Covid-19 vaccinations feeling they should believe the same about other vaccines. However, they noted that the observational study didn't directly measure people's beliefs or prove that mistrust of vaccines or the government caused flu vaccination rates to fall.
At the same time, the researchers noted one reassuring finding—flu vaccination levels remained fairly stable among those ages 65 and older.
Richard Leuchter, a resident physician at UCLA Health and lead author on the study, said he's concerned that people who previously never declined life-saving vaccines are now electing not to get them because of the controversy surrounding Covid-19 vaccines.
"This supports what I have seen in my clinical practice and suggests that information and policies specific to Covid-19 vaccines may be eroding more general faith in medicine and our government's role in public health," he said. (Schnirring, CIDRAP News, 6/16; Schoonover, Becker's Hospital Review, 6/17)