Connecticut officials say they will be much more prepared than they were for COVID-19 if a deadly flu virus now affecting dairy cows and other animals makes the jump to humans.

But questions remain about what the state is doing to protect its milk supply, keep farm workers safe and prepare for the possibility of another human pandemic.

"We've been planning for avian flu for decades," Dr. Manisha Juthani, commissioner of the state Department of Public Health, said in an interview Thursday. "We're very, very alert and aware, because this is one of those threats that we've been waiting for."

Experts agree the country is on much better footing when it comes to pandemic preparedness than it was in early 2020, when COVID exposed problems with the nation's public health infrastructure. But they say gaps still remain.

Meanwhile, state officials have not shared details about some of their own preparedness steps.

"Connecticut, I think we're doing as well as any state," said Dr. Dr. Megan Ranney, an emergency room physician and the dean of the Yale School of Public Health.

"But I do worry about that federal backup," Ranney added.

A flu that started in birds circles the globe and jumps to mammals — even sporadically to humans.

Influenza A, or H5N1 — more commonly called "bird flu," "avian flu" or "avian influenza" — began to spread in poultry in China around 1997 after it was first discovered in wild birds, according to the U.S. Centers for Disease Control and Prevention.

Bird flu continued to spread through poultry farms around the world in the early- and mid-2000s, picking up new genetic traits and splitting into new virus strains as it went.

The current worldwide outbreak of H5N1 started in 2022 when the virus began to spread widely in poultry farms and domestic chickens in the United States and Canada, according to the CDC.

Alarm bells went off in late 2022 and early 2023, when bird flu began to spread widely in mammals — reportedly killing tens of thousands of seals and sea lions, including at least 300 in New England.

The virus was first detected in dairy cows in March, according to the CDC. Since then, it's infected at least 36 herds in nine different states — a number experts have said is likely an undercount.

Recently the U.S. Department of Agriculture released viral sequencing data from cattle on different farms across multiple states indicating the current H5N1 outbreak originates from the same source. This means the different infected herds are likely due to cow-to-cow transmission, some likely asymptomatic, a USDA study shows.

To date, there have been 888 cases of people contracting H5N1 from animals, and 463 deaths, according to the World Health Organization — a fatality rate of about 52 percent.

But despite these cases of animal-to-human transmission, there's no evidence so far that H5N1 can spread easily between people — what scientists call "human-to-human" transmission. But the fact that it's spreading so widely among mammals has raised concerns about a potential human outbreak.

"That doesn't necessarily mean that it will jump to humans," said Dr. Albert Ko, who teaches epidemiology at the Yale School of Public Health.

"But certainly," Ko added, "much more surveillance is required."

How dairy farms in Connecticut are handling the outbreak

Connecticut's Avian Influenza Monitoring and Response Plan was last updated in 2017, before the current outbreak, and does not address how to protect cattle or dairy farms.

But bird flu hasn't been detected in dairy cattle or farm workers in Connecticut to date, and state agricultural officials say they've been working closely with public health officials, local dairies and industry groups to monitor the situation.

State Agriculture Commissioner Bryan P. Hulbert said his agency has emphasized the importance of measures to keep dairy animals and workers safe. It has advised dairies what the disease reporting requirements are and what to look for in animals and farm workers should they become symptomatic, according to Hulbert

"I think dairy farmers are very well aware," he said. "If there's a market scare regarding the safety of consuming milk, that's going to severely impact their operations."

The USDA has ordered dairy cattle be tested prior to being shipped between states, whether or not they have symptoms. It has also issued guidance that includes excluding birds and cats from livestock areas, not moving sick or exposed cows and using personal protective equipment like masks and gloves.

CT Insider queried three local dairies, local milk producer Hood and the Dairy Farmers of America milk marketing cooperative. about what biosecurity or testing measures they have in place. Two local dairies responded.

The UConn Dairy said it has stopped giving public tours and made respirators and gloves available to its workers, although it does not require its workers to use them. UConn also keeps its dairy and poultry operations strictly separate, according to Mary-Margaret Smith, who manages educational programs for the UConn Animal Science Department.

"We have a closed herd, so we don't receive any cows," Smith said. "If we were selling animals to another farm or breeder and it was a lactating cow, her milk would have to be tested."

Dairy Farmers of America, a marketing cooperative of 11,000 dairy farms that owns the Garelick Farms milk brand, said in a written statement it continues to "work closely with the industry and regulatory agencies such as the USDA to guide farmers."

The company did not say how many of its dairies, national or local, were implementing additional protective measures.

The state department of agriculture said it plans to make N95 masks and other personal protective equipment from the state's stockpile available to dairy farm workers but has not done so yet.

"The intent is to make PPE available as soon as possible," wrote Connecticut Department of Agriculture spokesperson Rebecca Eddy in an email received on May 9. "Our team met with DPH earlier today to determine the stockpile of PPE available. We will be notifying livestock farm workers and workers who may be in contact with raw milk with information on how they can obtain PPE."

Milk is safe, officials say — as long as it's pasteurized

The Food and Drug Administration found that about 20 percent of commercial milk it tested contained dead avian flu virus. The agency has, thus far, been unable to grow avian influenza from commercial, pasteurized milk samples — meaning that so far, there have been no living remnants of the virus. The FDA has, so far, said that the commercial, pasteurized milk supply is safe.

The FDA wrote a lengthy statement to CT Insider saying that it did not test milk from Connecticut specifically for H5N1. The agency stated that its efforts were designed to "study and assess the safety of pasteurized milk products at a national level."

"The pooled pre-pasteurization milk study is for the purpose of better understanding the viable virus levels in milk being sent to processing plants for pasteurization," wrote an FDA spokesperson. "As such, only states with confirmed H5N1 dairy herd infections were eligible to participate in this study, which did not include Connecticut."

The agency said that its retail sampling effort was "not designed to measure or detect the presence of H5N1 on specific premises" but to confirm the effectiveness of pasteurization on the virus. Retail milk processors may process milk from multiple herds in multiple states making retail products a bad candidates for identifying where H5N1 might be, the agency wrote.

"What we are identifying with H5N1 is that having gone through the pasteurization process, yes there were fragments, but these fragments are not infectious," Dr. Juthani said.

The prevalence of these fragments indicated there may be undetected herds of H5N1-positive dairy cattle, according to Juthani.

"To be clear, I would not recommend raw milk for any number of reasons, H5N1 being just the most recent reason," she said.

It's legal to sell raw milk in Connecticut, but those dairies must meet more stringent health and sanitation requirements that look at coliform bacterial levels and "somatic cell count." The bacteria levels indicate whether milk has been stored properly. High somatic cell counts can indicate a sick animal, according to the USDA. Failure to meet those standards can lead to recalls.

Officials say testing can be ramped up if needed; experts raise questions

Commissioner Juthani said Connecticut is not proactively screening either cows or dairy workers for H5N1 unless they show symptoms — something that hasn't happened so far.

"That is not a recommendation (from federal officials) at this moment," she said, adding that "the recommendation is to test those with some sort of symptom."

For now, Juthani said, any testing would take place at the state health lab at UConn, with positive tests confirmed by the CDC.

Testing capacity was a major bottleneck early in the country's response to the COVID pandemic. Juthani said she has asked federal officials whether something similar might happen with H5N1. They told her private labs could quickly begin testing for the virus so the public health response would not need to rely solely on federal and state testing capacity, she said.

"We've been reassured that if that was necessary, that could be ramped up," said Juthani.

For now, Juthani said, "We have the capacity to test any patient who comes forward in a situation where testing is required."

Still, some experts think federal officials aren't doing enough to monitor for H5N1 as it spreads.

Dr. Gail Hansen, the former state veterinarian of Kansas, said the USDA — and, by extension the, whole country — did not have a good emerging disease surveillance program in place. On top of that there's fear in the industry that finding H5N1 on a farm could lead people to stop buying milk.

If you're a dairy farmer, she asked, "Do you want to go down that road?"

"I've done a lot of disease surveillance in my time, and to do it right it takes some planning," Hansen said, explaining that you needed buy-in, planning and resources. "But there's this 'head in the sand' (idea) ... that if you don't look for disease, you won't find it."

She said this fear was exacerbated by the COVID pandemic and the general aura of disinformation and mistrust between the public and the government.

"COVID brought that mistrust to the surface," Hansen said. "If you think people were reluctant to get vaccinated themselves, what are you going to do if all of a sudden there's a vaccine for cattle but it's unknown if you can ship those cattle overseas? Will people be reluctant to buy milk from animals that have been vaccinated?"

Testing cows and dairy workers isn't just about protecting the milk supply or keeping workers safe, according to Ranney, as important as those goals are.

The more H5N1 spills over from animals into people, the more chances it has to mutate — and potentially evolve to spread from person to person.

"To my knowledge, there have been no cases of human-to-human transmission," Ranney said. "And that is the thing we have to prevent. And that involves monitoring and testing."

Questions about Conn. pandemic preparedness

If H5N1 does start spreading in people, officials say the state will be much better prepared than it was at the beginning of the COVID outbreak in early 2020.

"We're ahead of the game because we know the virus," Juthani said.

The state is currently redesigning its Pandemic Influenza Response Plan, which was last updated in late 2010, a spokesperson for the Department of Public Health said.

The Connecticut National Guard maintained a stockpile of COVID tests, personal protective equipment and other pandemic supplies at the state commodities warehouse in New Britain until March 2020, when it handed the warehouse over to the Department of Public Health.

"On an ongoing basis, we're not replenishing and having that active," Juthani said. "But we have a lot of stock."

In response to follow-up questions, the Department of Public Health said the stockpile currently has enough doses of Tamiflu — an antiviral drug that may be an effective treatment for H5N1 — to treat 4,699 patients. Those pills expire in October 2026, the department said.

The state stockpile also has 6.2 million N95 masks, which can protect the wearer from airborne viruses and other particles; 9 million surgical masks, which offer a lower level of respiratory protection; 5.1 million medical gowns; 4.3 million pairs of medical gloves; along with thousands of cots, face shields and body bags, according to the Department of Public Health.

Many hospitals and healthcare systems also now maintain their own stockpiles of protective equipment, Ranney said.

The department said the stockpile does not include lab supplies like nasal swabs, shortages of which contributed to testing backlogs early in the COVID pandemic.

Any ventilators received during the pandemic have either been distributed to hospitals or returned to the federal government, state officials said.

The Strategic National Stockpile, maintained by the federal government, also has stocks of personal protective equipment, ventilators, antiviral drugs and medical equipment that could be distributed to the states. However, the Strategic National Stockpile is only meant as "a short-term, stopgap buffer" to supplement state supplies and the private market, according to its website.

A separate federal stockpile, the National Pre-Pandemic Influenza Vaccine Stockpile, would supply the core components of a vaccine in the event of a human H5N1 pandemic. Two potential H5N1 vaccines are currently in clinical trials. Both require two doses. Federal officials have said they could produce enough vaccine within the first four months of a pandemic to inoculate about 68 million people, or a fifth of the country.

That raises one big question, according to Ko: "Can we make enough vaccine to protect everyone who's at risk?"

Ko, who advised the Lamont administration on its COVID response, said the state learned a lot about how to roll out large scale vaccine campaigns during the pandemic. Its 83 percent primary COVID vaccination rate is a testament to the success of that campaign, Ko said.

In the event of another pandemic, the state would rely on its 2021 Mass Vaccination Plan, a spokesperson said.

Still, the state can only distribute the antivirals or vaccines that it has — and that would depend largely on the federal government, Ranney said.

"An individual state government can do only so much to incentivize the production of antivirals and vaccines," Ranney said. "It really does need the federal government to lean in. I am concerned that there is inadequate investment."