#: Viruses like parties — doctors who specialize in infectious diseases give their verdict on New Year’s Eve

Everyone dreads that post-party contact-tracing email or group text to say someone has tested positive for the virus. They go something like this: “Thanks for making New Year’s Eve so special. I am sorry to say that Mildred came down with symptoms of COVID-19 and tested positive the morning after.”

As the second Christmas of the coronavirus pandemic approaches with an atmosphere of nervous optimism, cases continue to rise. COVID-19 has killed 787,064 Americans. As of Dec. 6, the daily average case count in the U.S. was 119,751, up 28% in two weeks, according to the New York Times tracker.

A Christmas party for the employees of a renewable energy company in Norway was blamed for being a “super-spreader event” for the highly contagious omicron variant, which scientists are closely tracking to see how immune it is to the current array of vaccines on the market, and how much serious illness it causes.

“Our working hypothesis is that at least half of the 120 participants were infected with the omicron variant during the party. This makes this, for now, the largest omicron outbreak outside South Africa,” Preben Aavitsland, a senior physician at the Norwegian Institute of Public Health, told Reuters.

Like the delta variant, omicron has spread around the world with speed, but public-health officials have said the structure of this variant has made it more powerful at reinfecting people who have already had COVID-19 and/or had a vaccine. But it has not — thus far — led to a spike in hospitalizations.

Still, some questions need to be asked before RSVP-ing to that end of year invitation: How many people will be there? Will there be good ventilation? Will the party be indoors or outdoors — a moot point if you’re living in a cold climate. How many households will be there? Will they all be vaccinated?

“Decision making has only become more complicated. There are no absolute answers,” said Dr. Andrew Pavia, the George and Esther Gross Presidential Professor at the University of Utah and head of the university hospital’s pediatric infectious-diseases unit.

In addition to how many people will be there, who will be there? Is this their first party of the season — or their 10th? “You might even consider the party behavior,” he added. “A crowded, drunken, and chaotic party like the archetype of an office party is different than a more modest gathering.”

Would he personally attend a New Year’s Eve party, if invited? “I would be comfortable attending a gathering of three to four households if the answers to the questions above were re-assuring,” Pavia told MarketWatch. “A bit boring perhaps, but it is a safe way to be around friends and family.”

Other factors: “Has everyone been boosted? Booster doses decrease the risk of breakthrough infection substantially, hence make the party safer. How careful are the attendees when not at the party?” he said. “If you know the others wear masks in crowded indoor spaces and are conscientious, the risk is reduced.”

About those boosters. While roughly 60% of the U.S. population are vaccinated, only 24% have received a booster shot so far. Research shows that Pfizer-BioNTech 
PFE,
-0.62%

BNTX,
-3.55%
and Moderna 
MRNA,
+0.37%
 boosters offer more antibodies, but Johnson & Johnson 
JNJ,
+0.60%
 boosters do still improve your immunity.

‘It’s a holidisaster’

Other medical experts advise against attending a party where coronavirus threatens to be an uninvited guest. “Would you and I go into a building where we can see smoke and hear fire alarms? That’s what omicron is,” said Dr. Gregory Poland, who studies the immunogenetics of vaccine response at the Mayo Clinic.

There are no good answers to the checklist of questions, he said. “Is there is a holiday party where there is no singing, dancing and standing in close quarters? If I were the virus, I’d be rubbing my hands in glee,” Poland said. “It’s not a holiday. It’s a holidisaster! Of course, America does not want to hear that.”

Some people are taking note. Earlier this month, Rio cancelled its famous New Year’s Eve celebrations for the second year running. Eduardo Paes, mayor of the Brazilian city, wrote on Twitter
TWTR,
+2.83%
on Saturday: “We respect science.” Similarly, Poland said Americans should also respect the science.

“Even in the face of delta, one out of every 405 Americas are dead from a virus that can be prevented with a 25-cent mask, a bit of distance and a free vaccine. This is unfathomable,” Poland told MarketWatch. “The virus is learning how to evade vaccine-induced immunity and virus-induced immunity.”

The Norwegian holiday party should be a warning for all partygoers, he added. “It’s the same way we got delta. People are getting infected with more than one variant. What’s to stop people getting infected with omicron and another coronavirus — something as infectious as omicron and deadly as delta?”

COVID-19 has killed more people in the U.S. than the estimated 675,000 deaths here from the 1918 influenza. “They didn’t even understand the nature of viruses yet,” Poland said. “We’ve allowed a scientific and economic problem to become a political and even a religious problem, and used as a tool to divide us.”

Luis Ostrosky, division director and professor, infectious diseases at the Department of Internal Medicine at the University of Texas in Houston, said he was discussing the issue of parties with his wife when MarketWatch came calling. “I feel that it’s OK to have small gatherings or two to three families,” Ostrosky said.

However, he added some important caveats: “Where everyone is vaccinated and/or boosted, where people understand that if they don’t feel well they should stay at home, and where there’s good ventilation and plenty of space along with a few dispensers of alcohol gel. Outdoor spaces are a plus.”

Treat each party invitation separately, advises Preeti Malani, chief health officer in the divisions of infectious diseases and geriatric medicine at the University of Michigan and a fellow of the Infectious Diseases Society of America. “Yes, I would consider going to a party with multiple households,” she told MarketWatch.

It’s safer to say no, she said, but staying home comes with increased isolation. “If party goers traveled for the Christmas holiday, I might consider that risk, which can be managed with additional testing.  If younger kids are coming — not yet eligible for vaccination — you might also consider testing depending on risk.”

Don’t be afraid to ask if everyone is vaccinated. “The better you know your fellow partygoers, the easier it is to know that everyone is fully vaccinated,” Malani said. “It could be a bit awkward to ask for documentation but reasonable to set this out as an expectation and a way to help reassure everyone.”

Poland might be persuaded to RSVP depending on where the party’s at. “Last year, the target was relatively stable,” he said. “Now the target is far less stable. It’s such a moving target. If I were in New York City, no way would I go. If I were in Podunk, Kansas, I might consider going.”

Related: 3 ways to protect against COVID-19 omicron variant during the holiday season — even if you’re vaccinated