Objective:

To examine the association between media statements promoting vitamin A as a treatment for measles and the increase in internet searches related to vitamin A and cod liver oil during the 2025 US measles outbreak.

Approach:

• Study Design: A cross-sectional study using Google Search Trends to analyze daily US search activity for 'vitamin A' measles and 'cod liver' measles from January 1 to June 1, 2025.
• Data Analysis: Utilized relative search fraction as a measure of public interest, calculated mean relative search fraction estimates and 95% confidence intervals (CIs), and performed interrupted time-series analysis with Bayesian segmented regression.

Key Findings:

• Search interest for 'vitamin A' measles peaked at 44% on March 22, 2025.
• Search interest for 'cod liver' measles peaked on March 5, 2025.
• Vitamin A search interest was a mean 7.5 percentage points higher than counterfactual estimates after media coverage began.
• Cod liver oil search interest was 1.3 percentage points higher than expected.

Interpretation:

The findings indicate an association between media statements and increased search interest in vitamin A and cod liver oil.

Limitations:

• The study could not determine if increased search activity led to actual use of vitamin A or cod liver oil.
• The analysis was limited to Google Search Trends data, reflecting search interest rather than broader public behavior or clinical outcomes.
• No control search terms were reported in the analysis.

Conclusion:

The study highlights the correlation between media statements and public interest in vitamin A during a measles outbreak.

Sources:

• JAMA Network Open