I’m a contact tracer who’s seen people lie about this virus. We need vaccine mandates.

I breathed a sigh of relief when I saw that governments and major workplaces like Google and Facebook had started to mandate Covid-19 vaccinations. President Joe Biden announced Thursday that all federal workers will be required to get them or face regular testing, following in the footsteps of employee mandates imposed by New York City, where I live, and California. Both were coronavirus epicenters in which tens of thousands were killed. Among them was my uncle, who shared my name and died of the virus in January, mere days before he qualified for a lifesaving vaccine as a senior.

As a community engagement specialist for New York City Health and Hospitals’ Covid Test and Trace program, I’ve encountered many families with similar experiences — but also households where members won’t get the vaccination even though it’s now available to them. While they might feel they have a personal right to refuse to be vaccinated and put their own health on the line, the bigger issue is how they might endanger those around them.

Vaccine mandates are crucial to protect others from the actions of those who have refused the treatment — particularly to protect them from loved ones who have concealed their behavior and decisions from those closest to them, putting them most at risk.

My contact tracing and vaccine outreach work has shown how mandates can protect us when family members won’t. This is extra important because the devastation of the illness is compounded by the emotional toll of anger and guilt within families when one member has endangered another.

I have spent the past year visiting households in northern Manhattan to inform people of their diagnosis if testing centers haven’t succeeded in reaching them by phone; to ask them about others they might have exposed to the virus; and to let them know what resources New York City has to help them isolate and keep others safe, particularly vaccines. At times, I’ve come across households where every member has caught the virus. Deception sometimes plays a role.

In one case, an immunocompromised matriarch lived with her adult children, all of whom had agreed to be tested to avoid masking at home. But one of her sons didn’t tell her he’d tested positive for Covid after socializing with infected friends. When I showed up and explained the reason for my visit — I’d been dispatched because he wasn’t answering our phone calls for contact tracing after his diagnosis — she was furious. She realized his dishonesty could have killed her.

During another visit, a man adamantly denied testing positive for Covid — or even going for a test in the first place — despite my showing him it was in the system under his name and address. His refusal to participate in our survey about things like contacts and current health status combined with his denials made me wonder if there were things he was keeping from his family. I eventually suspected his caginess stemmed from an affair he was keeping secret from his unwittingly exposed wife and children.

Unfortunately, even many people who normally welcome vaccinations have been skeptical about the Covid vaccine. Much of that is due to the politicized nature of the debate over Covid, wearing masks and getting immunized. Mandates can be necessary in this type of environment.

At the same time, the fact that those who don’t want to get the vaccination under the mandates are often being offered the option to get regularly tested instead could help minimize pushback. Even though this can allow the virus to spread, as people might not know they are infected until they are tested, it allows those who are hesitant to change their views as information comes out.

As a tracer, I was trained as a “vaccine ambassador” with techniques to overcome doubt, many of which stemmed from the expedited emergency use authorization of the vaccines. I explained how a vaccine works to boost immunity, how the full array of clinical trials had been conducted concurrently to save time and that the global urgency meant multiple countries putting their best researchers and massive amounts of government money forward. The few skeptics I came across nearly always listened respectfully to what I was saying, asked thoughtful questions and indicated that they would consider what I’d shared.

I myself never needed convincing because I already had seen what it could be like to not have a vaccination. One of the best tweets in favor of the Covid vaccine comes from human rights and environmental activist Mohamad Safa: “Remember that time you got Polio? No, you don’t. Because your parents got you vaccinated.” But I do remember how my brother suffered from rubella for not having been inoculated.

My four siblings and I span a 10-year age range that fell across the MMR — measles, mumps and rubella — vaccine divide. My baby sister and I were vaccinated; my older brother was not. In 1974, he developed rubella, or German measles. I can still remember him listless in bed, feverish and covered in a rash, as my parents were consumed with worry. With the MMR vaccine a requirement in most schools now, these are thankfully distant memories.

But some diseases still desperately need vaccines. In the 1990s, when I was doing work similar to tracing in the HIV field, I and many of my colleagues often talked of our hope for a vaccine that would mean our efforts would no longer be needed with such intense urgency. Now with Covid we have that lifesaving treatment, but people are still refusing to get it. Requiring vaccinations is a step in the right direction, a way to continue to save lives.