KJ Seung, the chief of strategy and policy for Massachusetts Covid Response from Partners in Health, who helped set up the contact tracing system, said it had been difficult for contact tracing authorities to clearly demonstrate that people were infected with the virus in small private gatherings infected.
Public revelations, like those at a factory or a wedding, were easier for them to follow. People often didn’t share the evenings when they had a cousin for dinner or drove a friend home from work, either out of shame or forgetfulness – and when they did, they were reluctant to give names.
“Small social gatherings are the hardest places to keep track of,” he said. But “when we spoke to tracers across the country, they said, yes, people get infected at these little gatherings.”
So much of the behavior related to the pandemic – including using masks and taking vaccines – seems to differ between people’s political party. However, the study found that birthdays in Republican and Democratic areas of the country resulted in similar increases in Covid infections. This suggests that while Democratic households were more likely to wear a mask when going for a walk, they may have been less different than Republicans in visiting a trusted friend.
“This element of your home is definitely a safe place and when you have your friends and family at home it just doesn’t feel risky,” said Dr. Ashish Jha, the dean of the School of Public Health at Brown University, who called the paper “creative” for finding an unusual way to capture disease transmissions that are otherwise difficult to measure.
For many Americans, birthday parties have become a lot safer in the past few months. The Centers for Disease Control and Prevention say it is safe for fully vaccinated individuals to gather indoors without wearing face coverings.
But for those who remain unvaccinated, the study is a reminder that even activities that feel safest pose a risk of infection. In many parts of the country, unvaccinated people are grouped by region or social group, which means birthday parties – and other festive, private occasions – can still be risky.